1
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Jones SM, Kirkwood-Donelson KI, Alexander GM, Perera L, Dudek SM, Jarmusch AK. Characterization of spironolactone and metabolites derivatized using Girard's reagent P using mass spectrometry and ion mobility spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2024; 38:e9775. [PMID: 38807480 DOI: 10.1002/rcm.9775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 04/26/2024] [Accepted: 05/07/2024] [Indexed: 05/30/2024]
Abstract
RATIONALE Spironolactone is a steroidal drug prescribed for a variety of medical conditions and is extensively metabolized quickly after administration. Measurement of spironolactone and its metabolites remains challenging using mass spectrometry (MS) due to in-source fragmentation and relatively poor ionization using electrospray ionization. Therefore, improved methods of measurements are needed, particularly in the case of small sample volumes. METHODS Girard's reagent P (GP) derivatization of spironolactone was employed to improve response and provide an MS-based solution to the measurement of spironolactone and its metabolites. We performed ultra-high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UHPLC-ESI-MS/MS) and ion mobility spectrometry (IMS)-high-resolution mass spectrometry (HRMS) to fully characterize the GP derivatization products. Analytes were studied in positive ionization mode, and MS/MS was performed using nonresonance and resonance excitation collision-induced dissociation. RESULTS We observed the successful GP derivatization of spironolactone and its metabolites using authentic chemical standards. A signal enhancement of 1-2 orders of magnitude was observed for GP-derivatized versions of spironolactone and its metabolites. Further, GP derivatization eliminated in-source fragmentation. Finally, we performed GP derivatization and ultra-high-performance liquid chromatography-high-resolution mass spectrometry (UHPLC-HRMS) in a small volume of murine serum (20 μL) from spironolactone-treated and control animals and observed multiple spironolactone metabolites only in the spironolactone-treated group. CONCLUSIONS GP derivatization was proven to have advantageous mass spectral performance (e.g., limiting in-source fragmentation, enhancing signals, and eliminating isobaric analytes) for spironolactone and its metabolites. This work and the detailed characterization using ultra-high-performance liquid chromatography-high-resolution tandem mass spectrometry (UHPLC-HRMS/MS) and IMS serve as the foundation for future developments in reaction optimization and/or quantitative assay development.
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Affiliation(s)
- Stephanie M Jones
- Neurobiology Laboratory, Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - Kaylie I Kirkwood-Donelson
- Immunity, Inflammation, and Disease Laboratory, Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - Georgia M Alexander
- Neurobiology Laboratory, Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - Lalith Perera
- Genome Integrity and Structural Biology Laboratory, Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - Serena M Dudek
- Neurobiology Laboratory, Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
| | - Alan K Jarmusch
- Immunity, Inflammation, and Disease Laboratory, Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
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2
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Venter P. The effects of modifiers on electrospray ionization for small-to-medium-sized molecules in comparison with solution-phase ionization. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2024; 38:e9749. [PMID: 38634146 DOI: 10.1002/rcm.9749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 03/20/2024] [Accepted: 03/21/2024] [Indexed: 04/19/2024]
Abstract
Modifiers are essential additives in electrospray ionization (ESI) mass spectrometric analysis to enhance the production of ionic species in the gas phase for the detection of small-to-medium-sized molecules in biological and aqueous samples. Therefore, an appropriate modifier, in conjunction with the right ionization polarity, is crucial for sensitive ESI mass spectrometric analysis. However, the charge carried by basic and acidic functional groups in solution is neither quantitatively nor qualitatively reflected in the MS spectrum. For example, adding an acidic modifier will cause sufficient protonation of a basic functional group in solution; however, this may result in inferior positive ESI compared to using a basic modifier. Another example is when the MS spectrum does not reflect the charge distribution of multiply charged molecules in solution. Therefore, this review will summarize and discuss the proposed mechanisms by which modifiers induce and influence ESI. It will also cover molecular characteristics that affect ESI, such as charge state and polarity, which result in a difference between solution-phase ionization and ESI.
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Affiliation(s)
- Pieter Venter
- Biomedical Research and Innovation Platform, South African Medical Research Council, Tygerberg, South Africa
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3
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Spesyvyi A, Žabka J, Polášek M, Malečková M, Khawaja N, Schmidt J, Kempf S, Postberg F, Charvat A, Abel B. Selected ice nanoparticle accelerator hypervelocity impact mass spectrometer (SELINA-HIMS): features and impacts of charged particles. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2024; 382:20230208. [PMID: 38736336 DOI: 10.1098/rsta.2023.0208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Accepted: 04/02/2024] [Indexed: 05/14/2024]
Abstract
The selected ice nanoparticle accelerator, SELINA, was used to prepare beams of single ice particles with positive or negative charge. Positively charged particles were prepared from deionized water and 0.05-0.2 molar solutions of sodium chloride in water, and negatively charged ice particles were generated from water without salt. Depending on the electrospray source configuration, the measured particles vary from 50 to 1000 nm in diameter. The kinetic energy per charge for all particles was set to 200 eV by the collisional equilibration in quadrupoles, which resulted in primary velocities up to 600 m/s for the lowest m/z particles. The electrospray ionization and thus particle formation from SELINA become less efficient with increasing salt concentration, resulting in a lower detected particle frequency and size. Good instrument operation is achievable for concentrations below 0.2 M. After we have verified and characterized positively and negatively charged ice particles, we have combined SELINA with a target and time-of-flight spectrometer for a 'proof-of-principle' post acceleration of 120 nm particles towards hypervelocity (v ~ 3000 m/s) and detection of fragments from the particle impact (SELINA-HIMS). General conditions are discussed for the acceleration of particles between 50 and 1000 nm to velocities well above 3000 m/s with SELINA-HIMS instrument. This article is part of the theme issue 'Dust in the Solar System and beyond'.
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Affiliation(s)
- Anatolii Spesyvyi
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences , Prague 18223, Czechia
| | - Ján Žabka
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences , Prague 18223, Czechia
| | - Miroslav Polášek
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences , Prague 18223, Czechia
| | - Michaela Malečková
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences , Prague 18223, Czechia
| | - Nozair Khawaja
- Institute of Geological Sciences, Freie Universität Berlin , Berlin, 12249, Germany
| | - Jürgen Schmidt
- Institute of Geological Sciences, Freie Universität Berlin , Berlin, 12249, Germany
| | - Sascha Kempf
- Laboratory for Atmospheric and Space Physics, University of Colorado , Boulder, CO, 80303, USA
| | - Frank Postberg
- Institute of Geological Sciences, Freie Universität Berlin , Berlin, 12249, Germany
| | - Ales Charvat
- Institute of Chemical Technology and Wilhelm Ostwald-Institute of Physical and Theoretical Chemistry , Leipzig, 04103, Germany
- Leibniz Institute of Surface Engineering , Leipzig, 04318, Germany
| | - Bernd Abel
- Institute of Chemical Technology and Wilhelm Ostwald-Institute of Physical and Theoretical Chemistry , Leipzig, 04103, Germany
- Leibniz Institute of Surface Engineering , Leipzig, 04318, Germany
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4
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Tu M, Xu W, Zhai Y. A Miniature Orthogonal Injection Ion Funnel (MO-IF) Providing Enhanced Performance for the Miniature Mass Spectrometer. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2024; 35:1363-1369. [PMID: 38683544 DOI: 10.1021/jasms.4c00100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/01/2024]
Abstract
The sensitivity of the miniature mass spectrometer (mini-MS) is largely restricted by the ion transmission in rough vacuum region. Even though various "in-line" ion transfer devices have improved mini-MS sensitivity, the severe dynamic gas is still weakening the efficiency of ion transmission in this region. Inspired by the "off-axis" ion funnel design in the lab-scale mass spectrometers, a miniature orthogonal injection ion funnel (MO-IF) was developed in this study for the mini-MS with a continuous atmospheric pressure interface. Capable of directing injected ions by 90° and then transport them forward to the downstream skimmer, the MO-IF enabled the separation of ions from the dynamic gas flow jetted out of the inlet capillary. The key factors were optimized for the MO-IF, including the effects of RF amplitude, DC electric fields, and the position of the repeller. Under optimized conditions, the MO-IF minimized the negative effects of dynamic gas and improved the ion transmission efficiency by ∼2-fold in comparison with the in-line injection ion funnel. As a result, a lower limit of detection of 0.5 ng/mL were obtained with good linearity for hypaconitine. Additionally, the MO-IF further decreased the buffer gas pressure in the second vacuum chamber and improved the mass resolution by 1.1-1.5 times at different scan rates.
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Affiliation(s)
- Min Tu
- School of Medical Technology, Beijing Institute of Technology, Beijing 100081, P. R. China
| | - Wei Xu
- School of Medical Technology, Beijing Institute of Technology, Beijing 100081, P. R. China
| | - Yanbing Zhai
- School of Medical Technology, Beijing Institute of Technology, Beijing 100081, P. R. China
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5
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Malaker SA. Glycoproteomics: Charting new territory in mass spectrometry and glycobiology. JOURNAL OF MASS SPECTROMETRY : JMS 2024; 59:e5034. [PMID: 38726698 DOI: 10.1002/jms.5034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 04/01/2024] [Accepted: 04/04/2024] [Indexed: 05/24/2024]
Abstract
Glycosylation is an incredibly common and diverse post-translational modification that contributes widely to cellular health and disease. Mass spectrometry is the premier technique to study glycoproteins; however, glycoproteomics has lagged behind traditional proteomics due to the challenges associated with studying glycosylation. For instance, glycans dissociate by collision-based fragmentation, thus necessitating electron-based fragmentation for site-localization. The vast glycan heterogeneity leads to lower overall abundance of each glycopeptide, and often, ion suppression is observed. One of the biggest issues facing glycoproteomics is the lack of reliable software for analysis, which necessitates manual validation and serves as a massive bottleneck in data processing. Here, I will discuss each of these challenges and some ways in which the field is attempting to address them, along with perspectives on how I believe we should move forward.
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Affiliation(s)
- Stacy A Malaker
- Department of Chemistry, Yale University, New Haven, Connecticut, USA
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6
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Nie CZ, Liu H, Huang XH, Zhou DY, Wang XS, Qin L. Prediction of mass spectrometry ionization efficiency based on COSMO-RS and machine learning algorithms. Analyst 2024; 149:3140-3151. [PMID: 38629585 DOI: 10.1039/d4an00301b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Non-targeted analysis of high-resolution mass spectrometry (MS) can identify thousands of compounds, which also gives a huge challenge to their quantification. The aim of this study is to investigate the impact of mass spectrometry ionization efficiency on various compounds in food at different solvent ratios and to develop a predictive model for mass spectrometry ionization efficiency to enable non-targeted quantitative prediction of unknown compounds. This study covered 70 compounds in 14 different mobile phase ratio environments in positive ion mode to analyze the rules of the matrix effect. With the organic phase ratio from low to high, most compounds changed by 1.0 log units in log IE. The addition of formic acid enhanced the signal but also promoted the matrix effect, which often occurred in compounds with strong ionization capacity. It was speculated that the matrix effect was mainly in the form of competitive charge and charged droplet' gasification sites during MS detection. Subsequently, we present a log IE prediction method built using the COSMO-RS software and the artificial neural network (ANN) algorithm to address this difficulty and overcome the shortcomings of previous models, which always ignore the matrix effect. This model was developed following the principles of QSAR modeling recommended by the Organization for Economic Cooperation and Development (OECD). Furthermore, we validated this approach by predicting the log IE of 70 compounds, including those not involved in the log IE model development. The results presented demonstrate that the method we put forward has an excellent prediction accuracy for log IE (R2pred = 0.880), which means that it has the potential to predict the log IE of new compounds without authentic standards.
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Affiliation(s)
- Cheng-Zhen Nie
- School of Food Science and Technology, State Key Laboratory of Marine Food Processing & Safety Control, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian 116034, China.
| | - Hao Liu
- School of Food Science and Technology, State Key Laboratory of Marine Food Processing & Safety Control, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian 116034, China.
| | - Xu-Hui Huang
- School of Food Science and Technology, State Key Laboratory of Marine Food Processing & Safety Control, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian 116034, China.
| | - Da-Yong Zhou
- School of Food Science and Technology, State Key Laboratory of Marine Food Processing & Safety Control, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian 116034, China.
| | - Xu-Song Wang
- School of Food Science and Technology, State Key Laboratory of Marine Food Processing & Safety Control, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian 116034, China.
| | - Lei Qin
- School of Food Science and Technology, State Key Laboratory of Marine Food Processing & Safety Control, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian 116034, China.
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7
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Hoang C, Uritboonthai W, Hoang L, Billings EM, Aisporna A, Nia FA, Derks RJE, Williamson JR, Giera M, Siuzdak G. Tandem Mass Spectrometry across Platforms. Anal Chem 2024; 96:5478-5488. [PMID: 38529642 PMCID: PMC11007677 DOI: 10.1021/acs.analchem.3c05576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 02/12/2024] [Accepted: 03/18/2024] [Indexed: 03/27/2024]
Abstract
PubChem serves as a comprehensive repository, housing over 100 million unique chemical structures representing the breadth of our chemical knowledge across numerous fields including metabolism, pharmaceuticals, toxicology, cosmetics, agriculture, and many more. Rapid identification of these small molecules increasingly relies on electrospray ionization (ESI) paired with tandem mass spectrometry (MS/MS), particularly by comparison to genuine standard MS/MS data sets. Despite its widespread application, achieving consistency in MS/MS data across various analytical platforms remains an unaddressed concern. This study evaluated MS/MS data derived from one hundred molecular standards utilizing instruments from five manufacturers, inclusive of quadrupole time-of-flight (QTOF) and quadrupole orbitrap "exactive" (QE) mass spectrometers by Agilent (QTOF), Bruker (QTOF), SCIEX (QTOF), Waters (QTOF), and Thermo QE. We assessed fragment ion variations at multiple collisional energies (0, 10, 20, and 40 eV) using the cosine scoring algorithm for comparisons and the number of fragments observed. A parallel visual analysis of the MS/MS spectra across instruments was conducted, consistent with a standard procedure that is used to circumvent the still prevalent issue of mischaracterizations as shown for dimethyl sphingosine and C20 sphingosine. Our analysis revealed a notable consistency in MS/MS data and identifications, with fragment ions' m/z values exhibiting the highest concordance between instrument platforms at 20 eV, the other collisional energies (0, 10, and 40 eV) were significantly lower. While moving toward a standardized ESI MS/MS protocol is required for dependable molecular characterization, our results also underscore the continued importance of corroborating MS/MS data against standards to ensure accurate identifications. Our findings suggest that ESI MS/MS manufacturers, akin to the established norms for gas chromatography mass spectrometry instruments, should standardize the collision energy at 20 eV across different instrument platforms.
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Affiliation(s)
- Corey Hoang
- Scripps
Center for Metabolomics and Mass Spectrometry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Winnie Uritboonthai
- Scripps
Center for Metabolomics and Mass Spectrometry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Linh Hoang
- Scripps
Center for Metabolomics and Mass Spectrometry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Elizabeth M. Billings
- Scripps
Center for Metabolomics and Mass Spectrometry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Aries Aisporna
- Scripps
Center for Metabolomics and Mass Spectrometry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Farshad A. Nia
- Department
of Integrative Structural and Computational Biology, Department of
Chemistry, The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California 92037, United States
| | - Rico J. E. Derks
- Center
for Proteomics and Metabolomics, Leiden
University Medical Center, Albinusdreef 2, Leiden 2333ZA, Netherlands
| | - James R. Williamson
- Department
of Integrative Structural and Computational Biology, Department of
Chemistry, The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California 92037, United States
| | - Martin Giera
- Center
for Proteomics and Metabolomics, Leiden
University Medical Center, Albinusdreef 2, Leiden 2333ZA, Netherlands
- The
Novo Nordisk Foundation Center for Stem Cell Medicine (reNEW), Leiden University Medical Center, Leiden 2333ZA, The Netherlands
| | - Gary Siuzdak
- Scripps
Center for Metabolomics and Mass Spectrometry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
- Departments
of Chemistry, Molecular, and Computational Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
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8
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Fowowe M, Yu A, Wang J, Onigbinde S, Nwaiwu J, Bennett AI, Mechref Y. Suppressing the background of LC-ESI-MS analysis of permethylated glycans using the active background ion reduction device. Electrophoresis 2024. [PMID: 38573014 DOI: 10.1002/elps.202300301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2023] [Revised: 03/18/2024] [Accepted: 03/22/2024] [Indexed: 04/05/2024]
Abstract
Mass spectrometry (MS) has revolutionized analytical chemistry, enabling precise identification and quantification of chemical species, which is pivotal for biomarker discovery and understanding complex biological systems. Despite its versatility, the presence of background ions in MS analysis hinders the sensitive detection of low-abundance analytes. Therefore, studies aimed at lowering background ion levels have become increasingly important. Here, we utilized the commercially available Active Background Ion Reduction Device (ABIRD) to suppress background ions and assess its effect on the liquid chromatography-electrospray ionization (LC-ESI)-MS analyses of N-glycans on the Q Exactive HF mass spectrometer. We also investigated the effect of different solvent vapors in the ESI source on N-glycan analysis by MS. ABIRD generally had no effect on high-mannose and neutral structures but reduced the intensity of some structures that contained sialic acid, fucose, or both when methanol vapor filled the ESI source. Based on our findings on the highest number of identified N-glycans from human serum, methanol vapor in the ion source compartment may enhance N-glycan LC-ESI-MS analyses by improving the desolvation of droplets formed during the ESI process due to its high volatility. This protocol may be further validated and extended to advanced bottom-up proteomic/glycoproteomic studies for the analysis of peptide/glycopeptide ions by MS.
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Affiliation(s)
- Mojibola Fowowe
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas, USA
| | - Aiying Yu
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas, USA
| | - Junyao Wang
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas, USA
| | - Sherifdeen Onigbinde
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas, USA
| | - Judith Nwaiwu
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas, USA
| | - Andrew I Bennett
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas, USA
| | - Yehia Mechref
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas, USA
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9
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Cordes MS, Gallagher ES. Molecular Dynamics Simulations of Native Protein Charging via Proton Transfer during Electrospray Ionization with Grotthuss Diffuse H 3O . Anal Chem 2024; 96:4146-4153. [PMID: 38427846 DOI: 10.1021/acs.analchem.3c05089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/03/2024]
Abstract
Unraveling the mechanism by which native proteins are charged through electrospray ionization (ESI) has been the focus of considerable research because observable charge states can be correlated to biophysical characteristics, such as protein folding and, thus, solution conformation. Difficulties in characterizing electrosprayed droplets have catalyzed the use of molecular dynamics (MD) to provide insights into the mechanisms by which proteins are charged and transferred to the gas phase. However, prior MD studies have utilized metal ions, primarily Na+, as charge carriers, even though proteins are primarily detected as protonated ions in the mass spectra. Here, we propose a modified MD protocol for simulating discrete Grotthuss diffuse H3O+ that is capable of dynamically altering amino-acid protonation states to model electrospray charging and gaseous ion formation of model proteins, ubiquitin, and myoglobin. Application of the protocol to the evaporation of acidic droplets enables a molecular perspective of H3O+ coordination and proton transfer to/from proteins, which is unfeasible with the metal charge carriers used in previous MD studies of ESI. Our protocol recreates experimentally observed charge-state distributions and supports the charge residue model (CRM) as the dominant mechanism of native protein ionization during ESI. Additionally, our results suggest that protonation is highly specific to individual residues and is correlated to the formation of localized hydrated regions on the protein surface as droplets desolvate. Considering the use of discrete H3O+ instead of Na+, the developed protocol is a necessary step toward developing a more comprehensive model of protein ionization during ESI.
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Affiliation(s)
- Michael S Cordes
- Department of Chemistry and Biochemistry, Baylor University, Waco, Texas 76798, United States
| | - Elyssia S Gallagher
- Department of Chemistry and Biochemistry, Baylor University, Waco, Texas 76798, United States
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10
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Williams PJH, Chagunda IC, McIndoe JS. OptiMS: An Accessible Program for Automating Mass Spectrometry Parameter Optimization and Configuration. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2024; 35:449-455. [PMID: 38345910 DOI: 10.1021/jasms.3c00354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/07/2024]
Abstract
Mass spectrometers have an enormous number of user-changeable parameters that drastically affect the observed mass spectrum. Using optimal parameters can significantly improve mass spectrometric data by increasing signal stability and signal-to-noise ratio, which decreases the limit of detection, thus revealing previously unobservable species. However, ascertaining optimal parameters is time-consuming, tedious, and made further challenging by the fact that parameters can act dependently on each other. Consequently, suboptimal parameters are frequently used during characterization, reducing the quality of results. OptiMS, an open-source, cross-platform program, was developed to simplify, accelerate, and more accurately determine optimal mass spectrometer parameters for a given system. It addresses common difficulties associated with existing software such as slow performance, high costs, and limited functionality. OptiMS efficacy was demonstrated through its application to multiple systems, quickly and successfully optimizing instrument parameters unassisted to maximize a user-defined metric, such as the intensity of a particular analyte. Additionally, among other features, OptiMS allows running of a sequence of predefined parameter configurations, reducing the workload of users wishing to obtain mass spectra under multiple sets of conditions.
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Affiliation(s)
- Peter J H Williams
- Department of Chemistry, University of Victoria, PO Box 1700 STN CSC, Victoria, BC V8W 2Y2, Canada
| | - Ian C Chagunda
- Department of Chemistry, University of Victoria, PO Box 1700 STN CSC, Victoria, BC V8W 2Y2, Canada
| | - J Scott McIndoe
- Department of Chemistry, University of Victoria, PO Box 1700 STN CSC, Victoria, BC V8W 2Y2, Canada
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11
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Ochirov O, Urban PL. Spontaneous Recycling of Electrosprayed Sample by Retrograde Motion of Microdroplets. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2024; 35:631-635. [PMID: 38353427 PMCID: PMC10921457 DOI: 10.1021/jasms.3c00444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 01/17/2024] [Accepted: 01/23/2024] [Indexed: 03/07/2024]
Abstract
Here, we discuss an interesting phenomenon occurring spontaneously near the sample liquid meniscus at the tip of the electrospray emitter. While most ejected droplets move from the emitter tip toward the counter electrode, some of the droplets decelerate and move backward to the liquid meniscus. When they hit the surface of the liquid meniscus, they either merge with the bulk liquid or get recharged during intermittent contact with the liquid meniscus and immediately reaccelerate toward the counter electrode. In some cases, while in contact with the meniscus they spontaneously form a secondary Taylor cone and emit progeny droplets. This observation suggests that the amount of electric charge transferred to such a droplet is sufficient to surpass the Rayleigh limit. Similar effects were previously observed for water as well as for NaCl-water and ethanol-water mixtures. However, here we observed it for electrolyte solutions commonly used in electrospray ionization mass spectrometry: methanol-water solutions with the addition of ammonium acetate, formic acid, or ammonium hydroxide. The reported phenomenon reveals the ongoing recycling of sample liquid in electrosprays. Such recycling can contribute to enhancement of sample utilization efficiency in electrospray ionization.
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Affiliation(s)
- Ochir Ochirov
- Department of Chemistry, National
Tsing Hua University, 101, Section 2, Kuang-Fu Rd., Hsinchu 300044, Taiwan
| | - Pawel L. Urban
- Department of Chemistry, National
Tsing Hua University, 101, Section 2, Kuang-Fu Rd., Hsinchu 300044, Taiwan
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12
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Shepherd SO, Green AW, Resendiz ES, Newton KR, Kurulugama RT, Prell JS. Effects of Nano-Electrospray Ionization Emitter Position on Unintentional In-Source Activation of Peptide and Protein Ions. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2024; 35:498-507. [PMID: 38374644 DOI: 10.1021/jasms.3c00371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/21/2024]
Abstract
Native ion mobility-mass spectrometry (IM-MS) typically introduces protein ions into the gas phase through nano-electrospray ionization (nESI). Many nESI setups have mobile stages for tuning the ion signal and extent of co-solute and salt adduction. However, tuning the position of the emitter capillary in nESI can have unintended downstream consequences for collision-induced unfolding or collision-induced dissociation (CIU/D) experiments. Here, we show that relatively small variations in the nESI emitter position can shift the midpoint (commonly called the "CID50" or "CIU50") potential of CID breakdown curves and CIU transitions by as much as 8 V on commercial instruments. A spatial "map" of the shift in CID50 for the loss of heme from holomyoglobin onto the emitter position on a Waters Synapt G2-Si mass spectrometer shows that emitter positions closer to the instrument inlet can result in significantly greater in-source activation, whereas different effects are found on an Agilent 6545XT instrument for the ions studied. A similar effect is observed for CID of the singly protonated leucine enkephalin peptide and Shiga toxin 1 subunit B homopentamer on the Waters Synapt G2-Si instrument. In-source activation effects on a Waters Synapt G2-Si are also investigated by examining the RMSD between CIU fingerprints acquired at different emitter positions and the shifts in CIU50 for structural transitions of bovine serum albumin and NIST monoclonal antibody.
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Affiliation(s)
- Samantha O Shepherd
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, Oregon 97403-1253, United States
| | - Austin W Green
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, Oregon 97403-1253, United States
| | - Elizabeth S Resendiz
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, Oregon 97403-1253, United States
| | - Kenneth R Newton
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, Oregon 97403-1253, United States
- Agilent Technologies, 5301 Stevens Creek Blvd, Santa Clara, California 95051, United States
| | - Ruwan T Kurulugama
- Agilent Technologies, 5301 Stevens Creek Blvd, Santa Clara, California 95051, United States
| | - James S Prell
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, Oregon 97403-1253, United States
- Materials Science Institute, University of Oregon, Eugene, Oregon 97403-1252, United States
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13
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Baglietto M, Benedetti B, Di Carro M, Magi E. Polar licit and illicit ingredients in dietary supplements: chemometric optimization of extraction and HILIC-MS/MS analysis. Anal Bioanal Chem 2024; 416:1679-1695. [PMID: 38334794 PMCID: PMC10899327 DOI: 10.1007/s00216-024-05173-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 01/16/2024] [Accepted: 01/24/2024] [Indexed: 02/10/2024]
Abstract
Many dietary supplements claim the ability to enhance sports performance and to improve the fitness of the consumers. Occasionally, along with legal ingredients, illicit compounds may be added without being labelled, leading to unintended doping. Hence, the aim of this study was to develop an analytical method to determine a set of 12 polar (logDpH=7 from -2.0 to +0.3) compounds including diuretics, stimulants, β2-agonists, methylxanthines, and sweeteners. Hydrophilic interaction liquid chromatography was chosen as separation strategy, coupled with tandem mass spectrometry. The instrumental method was optimized using a two-step design of experiments (DoE). Firstly, a Plackett-Burman (PB) DoE was performed to identify the more influencing variables affecting peak areas and chromatographic resolution among temperature, water percentage in the mobile phase, and flow rate, as well as type and concentration of buffers. Secondly, a D-optimal DoE was set, considering only the most significant variables from the PB-DoE results, achieving a deeper understanding of the retention mechanism. Sample processing by salt-assisted liquid-liquid extraction was studied through DoE as well, and the whole method showed recoveries in the range 40-107% and procedural precision ≤11% for all analytes. Finally, it was applied to real samples, in which the four methylxanthines and two artificial sweeteners were detected and quantified in the range of 0.02-192 mg g-1. These values were compared to the quantities declared on the DS labels, when possible. Furthermore, a sequence of MS/MS scans allowed detection of a signal in one of the samples, structurally similar to the β2-agonist clenbuterol.
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Affiliation(s)
- Matteo Baglietto
- Department of Chemistry and Industrial Chemistry, University of Genoa, via Dodecaneso 31, 16146, Genoa, Italy
| | - Barbara Benedetti
- Department of Chemistry and Industrial Chemistry, University of Genoa, via Dodecaneso 31, 16146, Genoa, Italy.
| | - Marina Di Carro
- Department of Chemistry and Industrial Chemistry, University of Genoa, via Dodecaneso 31, 16146, Genoa, Italy
| | - Emanuele Magi
- Department of Chemistry and Industrial Chemistry, University of Genoa, via Dodecaneso 31, 16146, Genoa, Italy
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14
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Chung NA, May JC, Robinson RAS, McLean JA. Solvent Composition Can Have a Measurable Influence on the Ion Mobility-Derived Collision Cross Section of Small Molecules. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2024; 35:234-243. [PMID: 38082535 DOI: 10.1021/jasms.3c00338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2024]
Abstract
Ion mobility (IM) is an important analytical technique for increasing identification coverage of metabolites in untargeted studies, especially when integrated into traditional liquid chromatography-mass spectrometry workflows. While there has been extensive work surrounding best practices to obtain and standardize collision cross section (CCS) measurements necessary for comparing across different IM techniques and laboratories, there has been little investigation into experimental factors beyond the mobility separation region that could potentially influence CCS measurements. The first-principles derived CCS of 15 chemical standards were evaluated across 27 aqueous:organic solvent compositions using a high-precision drift tube instrument. A small but measurable dependency of the CCS on the solvent composition was observed, with the larger analytes from this study (m/z > 400) exhibiting a characteristic increase in CCS at the intermediate (40-60%) solvent compositions. Parallels to the behavior of solvent viscosity and protonation site tautomers (protomers) were noted, although the origin of these solvent-dependent CCS trends is as yet unclear. Taken together, these findings document a solvent dependency on CCS, which, while minor (<0.5%), identifies an important need for reporting the solvent system when utilizing CCS in comparative ion mobility studies.
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Affiliation(s)
- Nadjali A Chung
- Center for Innovative Technology, Vanderbilt University, Nashville, Tennessee 37235, United States
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
- Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - Jody C May
- Center for Innovative Technology, Vanderbilt University, Nashville, Tennessee 37235, United States
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
- Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee 37235, United States
- Vanderbilt Institute for Integrative Biosystems Research and Education, Vanderbilt University, Nashville, Tennessee 37235, United States
- Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - Renã A S Robinson
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
- Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - John A McLean
- Center for Innovative Technology, Vanderbilt University, Nashville, Tennessee 37235, United States
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
- Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee 37235, United States
- Vanderbilt Institute for Integrative Biosystems Research and Education, Vanderbilt University, Nashville, Tennessee 37235, United States
- Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville, Tennessee 37235, United States
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15
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Schwenzer AK, Kruse L, Jooß K, Neusüß C. Capillary electrophoresis-mass spectrometry for protein analyses under native conditions: Current progress and perspectives. Proteomics 2024; 24:e2300135. [PMID: 37312401 DOI: 10.1002/pmic.202300135] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 05/16/2023] [Accepted: 05/23/2023] [Indexed: 06/15/2023]
Abstract
Native mass spectrometry is a rapidly emerging technique for fast and sensitive structural analysis of protein constructs, maintaining the protein higher order structure. The coupling with electromigration separation techniques under native conditions enables the characterization of proteoforms and highly complex protein mixtures. In this review, we present an overview of current native CE-MS technology. First, the status of native separation conditions is described for capillary zone electrophoresis (CZE), affinity capillary electrophoresis (ACE), and capillary isoelectric focusing (CIEF), as well as their chip-based formats, including essential parameters such as electrolyte composition and capillary coatings. Further, conditions required for native ESI-MS of (large) protein constructs, including instrumental parameters of QTOF and Orbitrap systems, as well as requirements for native CE-MS interfacing are presented. On this basis, methods and applications of the different modes of native CE-MS are summarized and discussed in the context of biological, medical, and biopharmaceutical questions. Finally, key achievements are highlighted and concluded, while remaining challenges are pointed out.
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Affiliation(s)
| | - Lena Kruse
- Department of Chemistry, Aalen University, Aalen, Germany
| | - Kevin Jooß
- Department of Chemistry and Molecular Biosciences, the Chemistry of Life Processes Institute, and the Proteomics Center of Excellence, Northwestern University, Evanston, Illinois, USA
- Division of Bioanalytical Chemistry, Amsterdam Institute of Molecular and Life Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
- Centre for Analytical Sciences Amsterdam (CASA), Amsterdam, The Netherlands
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16
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Habeck T, Maciel EVS, Kretschmer K, Lermyte F. Charge site manipulation to enhance top-down fragmentation efficiency. Proteomics 2024; 24:e2300082. [PMID: 37043727 DOI: 10.1002/pmic.202300082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 04/05/2023] [Accepted: 04/06/2023] [Indexed: 04/14/2023]
Abstract
In recent years, top-down mass spectrometry has become a widely used approach to study proteoforms; however, improving sequence coverage remains an important goal. Here, two different proteins, α-synuclein and bovine carbonic anhydrase, were subjected to top-down collision-induced dissociation (CID) after electrospray ionisation. Two high-boiling solvents, DMSO and propylene carbonate, were added to the protein solution in low concentration (2%) and the effects on the top-down fragmentation patterns of the proteins were systematically investigated. Each sample was measured in triplicate, which revealed highly reproducible differences in the top-down CID fragmentation patterns in the presence of a solution additive, even if the same precursor charge state was isolated in the quadrupole of the instrument. Further investigation supports the solution condition-dependent selective formation of different protonation site isomers as the underlying cause of these differences. Higher sequence coverage was often observed in the presence of additives, and the benefits of this approach became even more evident when datasets from different solution conditions were combined, as increases up to 35% in cleavage coverage were obtained. Overall, this approach therefore represents a promising opportunity to increase top-down fragmentation efficiency.
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Affiliation(s)
- Tanja Habeck
- Department of Chemistry, Clemens-Schöpf-Institute of Chemistry and Biochemistry, Technical University of Darmstadt, Darmstadt, Hessen, Germany
| | - Edvaldo Vasconcelos Soares Maciel
- Department of Chemistry, Clemens-Schöpf-Institute of Chemistry and Biochemistry, Technical University of Darmstadt, Darmstadt, Hessen, Germany
| | - Kevin Kretschmer
- Department of Chemistry, Clemens-Schöpf-Institute of Chemistry and Biochemistry, Technical University of Darmstadt, Darmstadt, Hessen, Germany
| | - Frederik Lermyte
- Department of Chemistry, Clemens-Schöpf-Institute of Chemistry and Biochemistry, Technical University of Darmstadt, Darmstadt, Hessen, Germany
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17
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Yang F, Urban RD, Lorenz J, Griebel J, Koohbor N, Rohdenburg M, Knorke H, Fuhrmann D, Charvat A, Abel B, Azov VA, Warneke J. Control of Intermediates and Products by Combining Droplet Reactions and Ion Soft-Landing. Angew Chem Int Ed Engl 2024; 63:e202314784. [PMID: 37917653 DOI: 10.1002/anie.202314784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 11/01/2023] [Accepted: 11/02/2023] [Indexed: 11/04/2023]
Abstract
Despite being recognized primarily as an analytical technique, mass spectrometry also has a large potential as a synthetic tool, enabling access to advanced synthetic routes by reactions in charged microdroplets or ionic thin layers. Such reactions are special and proceed primarily at surfaces of droplets and thin layers. Partial solvation of the reactants is usually considered to play an important role for reducing the activation barrier, but many mechanistic details still need to be clarified. In our study, we showcase the synergy between two sequentially applied "preparative mass spectrometry" methods: initiating accelerated reactions within microdroplets during electrospray ionization to generate gaseous ionic intermediates in high abundance, which are subsequently mass-selected and soft-landed to react with a provided reagent on a substrate. This allows the generation of products at a nanomolar scale, amenable to further characterization. In this proof-of-concept study, the contrasting reaction pathways between intrinsically neutral and pre-charged reagents, respectively, both in microdroplets and in layers generated by ion soft-landing are investigated. This provides new insights into the role of partially solvated reagents at microdroplet surfaces for increased reaction rates. Additionally, further insights into reactions of ions of the same polarity under various conditions is obtained.
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Affiliation(s)
- Fangshun Yang
- Leibniz Institute of Surface Engineering (IOM), Permoserstrasse 15, 04318, Leipzig, Germany
| | - Raphael D Urban
- Leibniz Institute of Surface Engineering (IOM), Permoserstrasse 15, 04318, Leipzig, Germany
| | - Jonas Lorenz
- Leibniz Institute of Surface Engineering (IOM), Permoserstrasse 15, 04318, Leipzig, Germany
| | - Jan Griebel
- Leibniz Institute of Surface Engineering (IOM), Permoserstrasse 15, 04318, Leipzig, Germany
| | - Nima Koohbor
- Leibniz Institute of Surface Engineering (IOM), Permoserstrasse 15, 04318, Leipzig, Germany
| | - Markus Rohdenburg
- Wilhelm-Ostwald-Institute for Physical and Theoretical Chemistry, University Leipzig, Linnéstrasse 2, 04103, Leipzig, Germany
| | - Harald Knorke
- Wilhelm-Ostwald-Institute for Physical and Theoretical Chemistry, University Leipzig, Linnéstrasse 2, 04103, Leipzig, Germany
| | - Daniel Fuhrmann
- Institute for Inorganic Chemistry, University Leipzig, Johannisallee 29, 04103, Leipzig, Germany
| | - Ales Charvat
- Leibniz Institute of Surface Engineering (IOM), Permoserstrasse 15, 04318, Leipzig, Germany
- Institute of Chemical Technology, University Leipzig, 04103, Leipzig, Germany
| | - Bernd Abel
- Leibniz Institute of Surface Engineering (IOM), Permoserstrasse 15, 04318, Leipzig, Germany
- Institute of Chemical Technology, University Leipzig, 04103, Leipzig, Germany
| | - Vladimir A Azov
- Department of Chemistry, University of the Free State, 9300, Bloemfontein, South Africa
| | - Jonas Warneke
- Leibniz Institute of Surface Engineering (IOM), Permoserstrasse 15, 04318, Leipzig, Germany
- Wilhelm-Ostwald-Institute for Physical and Theoretical Chemistry, University Leipzig, Linnéstrasse 2, 04103, Leipzig, Germany
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18
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Wei Y, Liang H, Liu S, Guan S, Ma K, Guan Y, Chen Y, Huang M, Wang X, Lan C. Development and validation of a sensitive LC-MS/MS method for the assay of four PARP inhibitors in human plasma and its application in ovarian cancer patients. J Pharm Biomed Anal 2024; 237:115758. [PMID: 37832476 DOI: 10.1016/j.jpba.2023.115758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 09/11/2023] [Accepted: 09/30/2023] [Indexed: 10/15/2023]
Abstract
PARP inhibitors have demonstrated marked efficacy in ovarian cancer patients with BRCA1/2 loss-of-function mutations. In this study, we established and validated a liquid chromatography-tandem mass spectrometry (LC-MS/MS) based method to simultaneously quantify the four frequently prescripted PARP inhibitors, namely niraparib, olaparib,fluzoparib, and pamiparib, in ovarian cancer. The mobile phase was 50 % methanol with 0.1 % formic acid at a flow rate of 0.3 mL/min, within 8 min run time. Four PARP inhibitors were separated on a Hypersil GOLD™ aQ C18 Polar Endcapped LC column (50 × 2.1 mm, 1.9 µm) at 35 ℃ and subjected to mass analysis using positive electro-spray ionization (ESI). The linear range of this method was 10-2000 ng/mL, 25-5000 ng/mL, and 50-10,000 ng/mL for niraparib, olaparib and fluzoparib, and pamiparib, respectively, with the correlation coefficients (r2) ≥ 0.99. Accuracies ranged from 93.12 %-110.71 and the inter- and intra-batch precisions were less than 15 % for all analytes in quality control samples. There was no significant matrix effect. Twenty-eight plasma samples were obtained from Sun Yat-sen University Cancer Center. The mean plasma concentrations (±SD) of niraparib and olaparib were 424.76 (±228.35) ng/mL and 1760.47 (±1739.69) ng/mL, respectively. The validated LC-MS/MS method allows the convient and efficient determination of four PARP inhibitors' exposure levels in ovarian cancer patients.
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Affiliation(s)
- Yuru Wei
- Laboratory of Drug Metabolism and Pharmacokinetics, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510060, China; Institute of Clinical Pharmacology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, Guangdong Province 510006, China; Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, Guangzhou, Guangdong Province, 510006, China
| | - Haixi Liang
- Department of Gynecologic Oncology, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou 510060, China
| | - Shu Liu
- State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou 510060, China
| | - Shaoxing Guan
- Laboratory of Drug Metabolism and Pharmacokinetics, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510060, China; Institute of Clinical Pharmacology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, Guangdong Province 510006, China; Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, Guangzhou, Guangdong Province, 510006, China
| | - Kaiyun Ma
- Laboratory of Drug Metabolism and Pharmacokinetics, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510060, China; Institute of Clinical Pharmacology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, Guangdong Province 510006, China; Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, Guangzhou, Guangdong Province, 510006, China
| | - Yanping Guan
- Laboratory of Drug Metabolism and Pharmacokinetics, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510060, China; Institute of Clinical Pharmacology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, Guangdong Province 510006, China; Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, Guangzhou, Guangdong Province, 510006, China
| | - Youhao Chen
- Laboratory of Drug Metabolism and Pharmacokinetics, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510060, China; Institute of Clinical Pharmacology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, Guangdong Province 510006, China; Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, Guangzhou, Guangdong Province, 510006, China
| | - Min Huang
- Laboratory of Drug Metabolism and Pharmacokinetics, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510060, China; Institute of Clinical Pharmacology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, Guangdong Province 510006, China; Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, Guangzhou, Guangdong Province, 510006, China
| | - Xueding Wang
- Laboratory of Drug Metabolism and Pharmacokinetics, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510060, China; Institute of Clinical Pharmacology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, Guangdong Province 510006, China; Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, Guangzhou, Guangdong Province, 510006, China.
| | - Chunyan Lan
- Department of Gynecologic Oncology, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou 510060, China.
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19
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Xu A, Tang LC, Jovanovic M, Regev O. Uncovering Distinct Peptide Charging Behaviors in Electrospray Ionization Mass Spectrometry Using a Large-Scale Dataset. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2024; 35:90-99. [PMID: 38095561 PMCID: PMC10767741 DOI: 10.1021/jasms.3c00325] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 11/20/2023] [Accepted: 11/22/2023] [Indexed: 12/26/2023]
Abstract
Electrospray ionization is a powerful and prevalent technique used to ionize analytes in mass spectrometry. The distribution of charges that an analyte receives (charge state distribution, CSD) is an important consideration for interpreting mass spectra. However, due to an incomplete understanding of the ionization mechanism, the analyte properties that influence CSDs are not fully understood. Here, we employ a machine learning-based approach and analyze CSDs of hundreds of thousands of peptides. Interestingly, half of the peptides exhibit charges that differ from what one would naively expect (the number of basic sites). We find that these peptides can be classified into two regimes (undercharging and overcharging) and that these two regimes display markedly different charging characteristics. Notably, peptides in the overcharging regime show minimal dependence on basic site count, and more generally, the two regimes exhibit distinct sequence determinants. These findings highlight the rich ionization behavior of peptides and the potential of CSDs for enhancing peptide identification.
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Affiliation(s)
- Allyn
M. Xu
- Department
of Mathematics, Courant Institute of Mathematical Sciences, New York University, New York, New York 10012, United States
| | - Lauren C. Tang
- Department
of Biological Sciences, Columbia University, New York, New York 10027, United States
| | - Marko Jovanovic
- Department
of Biological Sciences, Columbia University, New York, New York 10027, United States
| | - Oded Regev
- Computer
Science Department, Courant Institute of Mathematical Sciences, New York University, New York, New York 10012, United States
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20
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Zhuo X, He C, Cai R, Shi Q. Effect of salinity on molecular characterization of dissolved organic matter using ESI FT-ICR MS. Talanta 2024; 266:125005. [PMID: 37536107 DOI: 10.1016/j.talanta.2023.125005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 07/26/2023] [Accepted: 07/27/2023] [Indexed: 08/05/2023]
Abstract
Solid-phase extraction (SPE) coupled with negative-ion Electrospray ionization (ESI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) has been widely used for molecular characterization of dissolved organic matter (DOM). However, little attention has paid to test whether the salinity of the sample and the presence of chloride ions in water samples affect the molecular composition of DOM extracted by SPE (SPE-DOM). In this study, one natural organic matter standard and several natural waters were selected to investigate how salinity affects the molecular composition of SPE-DOM and the selectivity of chloride ion adducts formation with respect to the molecular structure of SPE-DOM in negative ion ESI FT-ICR MS analysis. The results show that the molecular composition of SPE-DOM varied in a sample made by different salinity; and the variation pattern of DOM composition was different among different water samples under the treatment of consistent salinity gradients. The chloride ions can't be completely removed from cartridges in conventional SPE, thus leading organic compounds in SPE-DOM to form [M+Cl]‾ adducts when performing ESI FT-ICR MS analysis. In addition, the molecules with high H/C and low O/C ratios were likely to form [M+Cl]‾ ions. The relative abundance of [M+Cl]‾ ions could increase with the increase of salinity. These results are instructive to guide the pretreatment and molecular characterization of DOM in water samples with different salinity. Overall, we proposed a modification to the SPE to minimum reduce the formation of chloride ion adducts during the isolation of DOM.
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Affiliation(s)
- Xiaocun Zhuo
- State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing, 102249, PR China
| | - Chen He
- State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing, 102249, PR China.
| | - Ruanhong Cai
- State Key Laboratory of Marine Environmental Science and College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361005, PR China
| | - Quan Shi
- State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing, 102249, PR China.
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21
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Qiu C, Li X, Li Z, Yang L, Wang W, Xu F, Ding CF. Simulation study of three new quadrupole ion funnels to improve low-mass ion transmission. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2023; 37:e9648. [PMID: 37953544 DOI: 10.1002/rcm.9648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 09/13/2023] [Accepted: 09/15/2023] [Indexed: 11/14/2023]
Abstract
RATIONALE By applying radio frequency (RF) and direct current (DC) voltages to corresponding ring electrodes, ion funnel (IF) can efficiently focus and transmit ions. However, IF has an inherent mass discrimination problem that will greatly limit low mass-to-charge (m/z) ion focusing and transmission. To improve the transmission efficiency (TE) of the IF, this paper explores three new profile quadrupole ion funnels (QIF). METHODS Computer simulations of the potential field distributions of QIFs and conventional IFs were performed to assess their focusing characteristics. To compare the TE, ion optics simulation programs SIMION and AXSIM were used to perform a series of simulations. Three QIF types (toroidal, cylindrical, and hyperbolic configurations) were used to improve ion TE, and their transmission and focus performance were also compared with conventional IF. RESULTS By simulating the trajectories of ions in the IF, the optimum electrical parameters for three new QIFs were obtained and compared with conventional IFs, with TE improvements recorded for m/z < 100 of 16%, 20%, and 13%. CONCLUSIONS The results indicate that studying these three new IF configurations has great research significance for improving sensitivity to low m/z ions in mass spectrometer instruments.
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Affiliation(s)
- Chaohui Qiu
- School of Material Science and Chemical Engineering, Ningbo University, Ningbo, China
| | - Xiaolong Li
- School of Material Science and Chemical Engineering, Ningbo University, Ningbo, China
| | - Zhe Li
- School of Material Science and Chemical Engineering, Ningbo University, Ningbo, China
| | - Liu Yang
- School of Material Science and Chemical Engineering, Ningbo University, Ningbo, China
| | - Weimin Wang
- School of Material Science and Chemical Engineering, Ningbo University, Ningbo, China
- Key Laboratory of Advanced Mass Spectrometry and Molecular Analysis of Zhejiang Province, Institute of Mass Spectrometry, Ningbo University, Ningbo, China
| | - Fuxing Xu
- School of Material Science and Chemical Engineering, Ningbo University, Ningbo, China
- Key Laboratory of Advanced Mass Spectrometry and Molecular Analysis of Zhejiang Province, Institute of Mass Spectrometry, Ningbo University, Ningbo, China
| | - Chuan-Fan Ding
- School of Material Science and Chemical Engineering, Ningbo University, Ningbo, China
- Key Laboratory of Advanced Mass Spectrometry and Molecular Analysis of Zhejiang Province, Institute of Mass Spectrometry, Ningbo University, Ningbo, China
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22
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Miskulin A, Wallace B, Gill C, Hore D. A strategy for the detection of benzodiazepine drugs using low-resolution paper-spray mass spectrometry for harm reduction drug checking. Drug Test Anal 2023. [PMID: 38145889 DOI: 10.1002/dta.3630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 11/02/2023] [Accepted: 12/07/2023] [Indexed: 12/27/2023]
Abstract
The ability to detect newly emerging substances is of great importance in reducing harms for people who use drugs. New psychoactive substances including novel benzodiazepines in the illicit drug supply have been linked to high rates of overdose deaths while complicating drug checking as an overdose prevention strategy. Paper-spray mass spectrometry (PS-MS) has emerged as a novel strategy to rapidly detect trace components in street drug samples. While targeted, low-resolution PS-MS methods have proven effective, newly emerging substances are often missed. To address this, a method was applied to low-resolution full-scan PS-MS data to aid in the early detection and identification of novel benzodiazepines in the unregulated drug supply. Using the developed method, true positives rates of 0.89 and 0.75 were achieved for bromazolam and etizolam in street samples obtained in a community drug checking service. The applicability of the method was further demonstrated for a novel benzodiazepine, desalkylgidazepam, that has recently emerged in the illicit drug supply.
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Affiliation(s)
- Allie Miskulin
- Department of Chemistry, University of Victoria, Victoria, British Columbia, Canada
| | - Bruce Wallace
- School of Social Work, University of Victoria, Victoria, British Columbia, Canada
- Canadian Institute for Substance Use Research, University of Victoria, Victoria, British Columbia, Canada
| | - Chris Gill
- Department of Chemistry, University of Victoria, Victoria, British Columbia, Canada
- Canadian Institute for Substance Use Research, University of Victoria, Victoria, British Columbia, Canada
- Department of Chemistry, Applied Environmental Research Laboratories (AERL), Vancouver Island University, Nanaimo, British Columbia, Canada
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, USA
| | - Dennis Hore
- Department of Chemistry, University of Victoria, Victoria, British Columbia, Canada
- Canadian Institute for Substance Use Research, University of Victoria, Victoria, British Columbia, Canada
- Department of Computer Science, University of Victoria, Victoria, British Columbia, Canada
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23
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Tamama K. Dilute and shoot approach for toxicology testing. Front Chem 2023; 11:1278313. [PMID: 38146427 PMCID: PMC10749341 DOI: 10.3389/fchem.2023.1278313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Accepted: 11/27/2023] [Indexed: 12/27/2023] Open
Abstract
Toxicology testing is performed in clinical settings, forensic settings, and for controlling doping. Drug screening is a toxicology test to determine if drugs are present in biological samples. The most common specimen type for drug testing is urine, as drugs and/or their metabolites are often more concentrated in the urine, extending the detection window of drugs. The dilute-and-shoot method is a simple procedure used in toxicology testing, where a sample is diluted before being directly injected into the liquid chromatography-mass spectrometry (LC-MS) system. This method is easy, quick, and cost-saving, and can be used for protein-poor liquid specimens such as urine. Thus, it is reasonable and attractive for busy toxicology laboratories to combine the dilute-and-shoot method with high-resolution hyphenated-MS for urine drug screening. This method has several disadvantages, including a suboptimal detection capability for certain analytes, as well as interference from co-eluting matrix components called matrix effects, in which co-eluting matrix molecules alter the ionization efficiency of the analyte molecules at the ionization source in LC-MS, altering (mostly reducing) the analyte detection capability. The matrix effect testing is essential for the validation of LC-MS-based assays. A reasonable approach to addressing these undesirable effects would be to minimize these components. The most straightforward approach is to reduce the amounts of matrix components by using a higher dilution of the specimen and a lower volume for specimen injection. Optimization of the chromatographic separation is another reasonable approach for reducing co-eluting matrix components with the analyte.
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Affiliation(s)
- Kenichi Tamama
- Clinical Laboratories, University of Pittsburgh Medical Center, Pittsburgh, PA, United States
- Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, United States
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24
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Beloborodov SS, Schneider BB, Oleschuk RD, Yves Le Blanc JC. Open Port Interface for Coupling Capillary Electrophoresis and Mass Spectrometry: Performance Evaluation for Capillary Isoelectric Focusing. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023; 34:2107-2116. [PMID: 37650584 DOI: 10.1021/jasms.3c00060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
Abstract
Capillary electrophoresis (CE) combined with mass spectrometry (MS) is a powerful analytical technique that utilizes the resolving power of CE and the mass-detection capabilities of MS. In many cases, CE is coupled to MS via a sheath-flow interface (SFI). This interface has a simple design and can be easily constructed; however, it often suffers from issues such as MS signal suppression, interference of MS and CE electrical circuits, and the inability to set an optical point of detection close to the capillary end due to the specific design of the coupling union. In this paper, we describe a novel coupling of CE and MS based upon the open port interface (OPI). The OPI differs from classical sheath flow interfaces by operating at flow rates at least 1 order of magnitude higher. In addition to the flow rate difference, the OPI provides more efficient mixing of the capillary eluates with the transport fluid and thus minimizes MS signal suppression. In this work, we compared the performance of OPI and SFI in a series of capillary isoelectric focusing (cIEF) experiments with 5 pI markers, carbonic anhydrase II and NIST antibody. The evaluation criteria for the comparison of the OPI and SFI were analytical sensitivity, reproducibility, and pI marker linearity. Given the extent of sample dilution in the OPI, we also compared the peak resolution determined using an upstream UV detector to those determined by the downstream mass spectrometer. The results suggested that the OPI configuration reduced signal suppression, with no adverse effect on peak resolution. In addition, the OPI provided better decoupling of the CE and MS potentials as well as reduced signal dependence upon the sheath liquid composition. While these results are preliminary, they suggest that the OPI is a viable approach for CE-MS coupling.
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Affiliation(s)
| | | | - Richard D Oleschuk
- Department of Chemistry, Queen's University, 90 Bader Lane, Kingston, Ontario K7L 3N6, Canada
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25
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Overdahl K, Collier JB, Jetten AM, Jarmusch AK. Signal Response Evaluation Applied to Untargeted Mass Spectrometry Data to Improve Data Interpretability. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023; 34:1941-1948. [PMID: 37524076 PMCID: PMC10485927 DOI: 10.1021/jasms.3c00220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 07/18/2023] [Accepted: 07/20/2023] [Indexed: 08/02/2023]
Abstract
Feature finding is a common way to process untargeted mass spectrometry (MS) data to obtain a list of chemicals present in a sample. Most feature finding algorithms naïvely search for patterns of unique descriptors (e.g., m/z, retention time, and mobility) and provide a list of unannotated features. There is a need for solutions in processing untargeted MS data, independent of chemical or origin, to assess features based on measurement quality with the aim of improving interpretation. Here, we report the signal response evaluation as a method by which to assess the individual features observed in untargeted MS data. The basis of this method is the ubiquitous relationship between the amount and response in all MS measurements. Three different metrics with user-defined parameters can be used to assess the monotonic or linear relationship of each feature in a dilution series or multiple injection volumes. We demonstrate this approach in metabolomics data obtained from a uniform biological matrix (NIST SRM 1950) and a variable biological matrix (murine kidney tissue). The code is provided to facilitate implementation of this data processing method.
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Affiliation(s)
- Kirsten
E. Overdahl
- Immunity, Inflammation, and Disease
Laboratory, Division of Intramural Research, National Institute of
Environmental Health Sciences, National
Institutes of Health, Research
Triangle Park, North Carolina 27709, United States
| | - Justin B. Collier
- Immunity, Inflammation, and Disease
Laboratory, Division of Intramural Research, National Institute of
Environmental Health Sciences, National
Institutes of Health, Research
Triangle Park, North Carolina 27709, United States
| | - Anton M. Jetten
- Immunity, Inflammation, and Disease
Laboratory, Division of Intramural Research, National Institute of
Environmental Health Sciences, National
Institutes of Health, Research
Triangle Park, North Carolina 27709, United States
| | - Alan K. Jarmusch
- Immunity, Inflammation, and Disease
Laboratory, Division of Intramural Research, National Institute of
Environmental Health Sciences, National
Institutes of Health, Research
Triangle Park, North Carolina 27709, United States
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26
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Wang T, Li H, Allen N, Ferraro I, Li A. Ultra-low current electrospray ionization of chloroform solution for the analysis of perfluorinated sulfonic acids. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2023; 37 Suppl 1:e9501. [PMID: 36879515 DOI: 10.1002/rcm.9501] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 02/13/2023] [Accepted: 03/03/2023] [Indexed: 06/18/2023]
Abstract
RATIONALE Femtoamp and picoamp electrospray ionization (ESI) characteristics of a nonpolar solvent were explored. The direct ESI mass spectrometry analysis of chloroform extract solution enabled rapid analysis of perfluorinated sulfonic acid analytes in drinking water. METHODS Neat chloroform solvent and extracts were directly used in a typical wire-in ESI setup using micrometer emitter tips. Ionization currents were measured with femtoamp sensitivity while ramping the spray voltage from 0 to -5000 V. Methanol was used as a comparison to illustrate the characteristics of electrospraying chloroform. The effects of spray voltage and inlet temperature were studied. A liquid-liquid extraction workflow was developed to analyze perfluorooctanoate sulfonate (PFOS) in drinking water using an ion-trap mass spectrometer. RESULTS The ionization onset of chloroform solution was 41 ± 17 fA at 300 V. The ionization current gradually increased with voltage while remaining below 100 pA when using voltages up to -5000 V. The ion signal of PFOS was significantly enhanced to improve the limit of detection (LoD) to 25 ppt in chloroform. Coupled with a liquid-liquid extraction workflow, LoD of 0.38-5.1 ppt and a quantitation range of 5-400 ppt were achieved for perfluorinated sulfonic compounds in 1-ml water samples. CONCLUSIONS Femtoamp and picoamp modes expand the solvent compatibility range of ESI and can enable quantitative analysis in parts per trillion (ppt) concentrations.
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Affiliation(s)
| | - Huishan Li
- University of New Hampshire, Durham, NH, USA
| | | | - Ian Ferraro
- University of New Hampshire, Durham, NH, USA
| | - Anyin Li
- University of New Hampshire, Durham, NH, USA
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27
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Saw YL, Boughton JR, Wroniuk FL, Mostafa ME, Pellegrinelli PJ, Calvez SA, Kaplitz AS, Perez LJ, Edwards JL, Grinias JP. Use of N-(4-aminophenyl)piperidine derivatization to improve organic acid detection with supercritical fluid chromatography-mass spectrometry. J Sep Sci 2023; 46:e2300343. [PMID: 37603367 DOI: 10.1002/jssc.202300343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 07/28/2023] [Accepted: 07/31/2023] [Indexed: 08/22/2023]
Abstract
The analysis of organic acids in complex mixtures by LC-MS can often prove challenging, especially due to the poor sensitivity of negative ionization mode required for detection of these compounds in their native (i.e., underivatized or untagged) form. These compounds have also been difficult to measure using supercritical fluid chromatography (SFC)-MS, a technique of growing importance for metabolomic analysis, with similar limitations based on negative ionization. In this report, the use of a high proton affinity N-(4-aminophenyl)piperidine derivatization tag is explored for the improvement of organic acid detection by SFC-MS. Four organic acids (lactic, succinic, malic, and citric acids) with varying numbers of carboxylate groups were derivatized with N-(4-aminophenyl)piperidine to achieve detection limits down to 0.5 ppb, with overall improvements in detection limit ranging from 25-to-2100-fold. The effect of the derivatization group on sensitivity, which increased by at least 200-fold for compounds that were detectable in their native form, and mass spectrometric detection are also described. Preliminary investigations into the separation of these derivatized compounds identified multiple stationary phases that could be used for complete separation of all four compounds by SFC. This derivatization technique provides an improved approach for the analysis of organic acids by SFC-MS, especially for those that are undetectable in their native form.
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Affiliation(s)
- Yih Ling Saw
- Department of Chemistry & Biochemistry, Rowan University, Glassboro, New Jersey, USA
| | - John R Boughton
- Department of Chemistry & Biochemistry, Rowan University, Glassboro, New Jersey, USA
| | - Faith L Wroniuk
- Department of Chemistry & Biochemistry, Rowan University, Glassboro, New Jersey, USA
| | | | - Peter J Pellegrinelli
- Department of Chemistry & Biochemistry, Rowan University, Glassboro, New Jersey, USA
| | - Samantha A Calvez
- Department of Chemistry & Biochemistry, Rowan University, Glassboro, New Jersey, USA
| | - Alexander S Kaplitz
- Department of Chemistry & Biochemistry, Rowan University, Glassboro, New Jersey, USA
| | - Lark J Perez
- Department of Chemistry & Biochemistry, Rowan University, Glassboro, New Jersey, USA
| | - James L Edwards
- Department of Chemistry, Saint Louis University, St. Louis, Missouri, USA
| | - James P Grinias
- Department of Chemistry & Biochemistry, Rowan University, Glassboro, New Jersey, USA
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28
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Penanes P, Gorshkov V, Ivanov MV, Gorshkov MV, Kjeldsen F. Potential of Negative-Ion-Mode Proteomics: An MS1-Only Approach. J Proteome Res 2023; 22:2734-2742. [PMID: 37395192 PMCID: PMC10407931 DOI: 10.1021/acs.jproteome.3c00307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Indexed: 07/04/2023]
Abstract
Current proteomics approaches rely almost exclusively on using the positive ionization mode, resulting in inefficient ionization of many acidic peptides. This study investigates protein identification efficiency in the negative ionization mode using the DirectMS1 method. DirectMS1 is an ultrafast data acquisition method based on accurate peptide mass measurements and predicted retention times. Our method achieves the highest rate of protein identification in the negative ion mode to date, identifying over 1000 proteins in a human cell line at a 1% false discovery rate. This is accomplished using a single-shot 10 min separation gradient, comparable to lengthy MS/MS-based analyses. Optimizing separation and experimental conditions was achieved by utilizing mobile buffers containing 2.5 mM imidazole and 3% isopropanol. The study emphasized the complementary nature of data obtained in positive and negative ion modes. Combining the results from all replicates in both polarities increased the number of identified proteins to 1774. Additionally, we analyzed the method's efficiency using different proteases for protein digestion. Among the four studied proteases (LysC, GluC, AspN, and trypsin), trypsin and LysC demonstrated the highest protein identification yield. This suggests that digestion procedures utilized in positive-mode proteomics can be effectively applied in the negative ion mode. Data are deposited to ProteomeXchange: PXD040583.
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Affiliation(s)
- Pelayo
A. Penanes
- Department
of Biochemistry and Molecular Biology, University
of Southern Denmark, DK-5230 Odense M, Denmark
| | - Vladimir Gorshkov
- Department
of Biochemistry and Molecular Biology, University
of Southern Denmark, DK-5230 Odense M, Denmark
| | - Mark V. Ivanov
- V.
L. Talrose Institute for Energy Problems of Chemical Physics, N. N. Semenov Federal Research Center for Chemical
Physics, Russian Academy of Sciences, 38 Leninsky Pr., Bld. 2, Moscow 119334, Russia
| | - Mikhail V. Gorshkov
- V.
L. Talrose Institute for Energy Problems of Chemical Physics, N. N. Semenov Federal Research Center for Chemical
Physics, Russian Academy of Sciences, 38 Leninsky Pr., Bld. 2, Moscow 119334, Russia
| | - Frank Kjeldsen
- Department
of Biochemistry and Molecular Biology, University
of Southern Denmark, DK-5230 Odense M, Denmark
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29
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Karatt TK, Muhammed Ajeebsanu M, Karakka Kal AK, Subhahar MB, Sathiq MA, Laya S. Electrospray ionization mass spectrometry adduct formation by mobile phase additives: A case study using nitrile functional groups containing selective androgen receptor modulators. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2023; 37:e9530. [PMID: 37125537 DOI: 10.1002/rcm.9530] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 04/27/2023] [Accepted: 04/27/2023] [Indexed: 06/17/2023]
Abstract
RATIONALE The formation of mass adducts is common during electrospray ionization mass spectrometry (ESI-MS). However, the mechanism that leads to adduct formation is poorly understood and difficult to control. Multiplication of mass adducts at once will adversely impact the sensitivity of mass analysis and cause misinterpretation of the level of detection. Prior studies on selective androgen receptor modulators (SARMs) revealed an immense mass adduct formation in both positive and negative ESI modes. METHODS In this study, additives in the mobile phases are investigated as a potential means of controlling mass adduct formation in various SARMs. RESULTS The first evidence of chloride adduct formation when SARMs are detected via ESI-MS has been reported in this research. A series of mobile phase combinations were tested to achieve the optimal condition for HPLC-MS. A comparison was also made between adduct formation on various grades of water used for preparing the mobile phase. A validation study using equine urine and plasma was also conducted to assess the suitability of the developed method. CONCLUSION The results of this study will allow for a more accurate identification of SARMs, which will make it easier to investigate their illicit use in horse racing.
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Affiliation(s)
- Tajudheen Kunhamu Karatt
- Equine Forensic Unit, Central Veterinary Research Laboratory, Dubai, United Arab Emirates
- Post Graduate and Research Department of Chemistry, Jamal Mohamed College (Affiliated to Bharathidasan University), Tiruchirappalli, India
| | | | | | | | - Mohamedkhani Anwar Sathiq
- Post Graduate and Research Department of Chemistry, Jamal Mohamed College (Affiliated to Bharathidasan University), Tiruchirappalli, India
| | - Saraswathy Laya
- Department of Chemistry, College of Science, United Arab Emirates University, Al Ain, United Arab Emirates
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30
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Potiszil C, Yamanaka M, Sakaguchi C, Ota T, Kitagawa H, Kunihiro T, Tanaka R, Kobayashi K, Nakamura E. Organic Matter in the Asteroid Ryugu: What We Know So Far. Life (Basel) 2023; 13:1448. [PMID: 37511823 PMCID: PMC10381145 DOI: 10.3390/life13071448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 06/20/2023] [Accepted: 06/21/2023] [Indexed: 07/30/2023] Open
Abstract
The Hayabusa2 mission was tasked with returning samples from the C-complex asteroid Ryugu (1999 JU3), in order to shed light on the formation, evolution and composition of such asteroids. One of the main science objectives was to understand whether such bodies could have supplied the organic matter required for the origin of life on Earth. Here, a review of the studies concerning the organic matter within the Ryugu samples is presented. This review will inform the reader about the Hayabusa2 mission, the nature of the organic matter analyzed and the various interpretations concerning the analytical findings including those concerning the origin and evolution of organic matter from Ryugu. Finally, the review puts the findings and individual interpretations in the context of the current theories surrounding the formation and evolution of Ryugu. Overall, the summary provided here will help to inform those operating in a wide range of interdisciplinary fields, including planetary science, astrobiology, the origin of life and astronomy, about the most recent developments concerning the organic matter in the Ryugu return samples and their relevance to understanding our solar system and beyond. The review also outlines the issues that still remain to be solved and highlights potential areas for future work.
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Affiliation(s)
- Christian Potiszil
- The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University, Yamada 827, Misasa, Tottori 682-0193, Japan
| | - Masahiro Yamanaka
- The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University, Yamada 827, Misasa, Tottori 682-0193, Japan
| | - Chie Sakaguchi
- The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University, Yamada 827, Misasa, Tottori 682-0193, Japan
| | - Tsutomu Ota
- The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University, Yamada 827, Misasa, Tottori 682-0193, Japan
| | - Hiroshi Kitagawa
- The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University, Yamada 827, Misasa, Tottori 682-0193, Japan
| | - Tak Kunihiro
- The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University, Yamada 827, Misasa, Tottori 682-0193, Japan
| | - Ryoji Tanaka
- The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University, Yamada 827, Misasa, Tottori 682-0193, Japan
| | - Katsura Kobayashi
- The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University, Yamada 827, Misasa, Tottori 682-0193, Japan
| | - Eizo Nakamura
- The Pheasant Memorial Laboratory for Geochemistry and Cosmochemistry, Institute for Planetary Materials, Okayama University, Yamada 827, Misasa, Tottori 682-0193, Japan
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31
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Liu Y, Ma C, Sun J. Integrated FT-ICR MS and metabolome reveals diatom-derived organic matter by bacterial transformation under warming and acidification. iScience 2023; 26:106812. [PMID: 37213222 PMCID: PMC10197009 DOI: 10.1016/j.isci.2023.106812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 02/21/2023] [Accepted: 05/01/2023] [Indexed: 05/23/2023] Open
Abstract
Bacterial transformation and processing of diatom-derived organic matter (OM) is extremely important for the cycling of production and energy in marine ecosystems; this process contributes to the production of microbial food webs. In this study, a cultivable bacterium (Roseobacter sp. SD-R1) from the marine diatom Skeletonema dohrnii were isolated and identified. A combined Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS)/untargeted metabolomics approach was used to synthesize the results of bacterial transformation with dissolved OM (DOM) and lysate OM (LOM) under warming and acidification through laboratory experiments. Roseobacter sp. SD-R1 had different preferences for the conversion of molecules in S. dohrnii-derived DOM and LOM treatments. The effects of warming and acidification contribute to the increased number and complexity of molecules of carbon, hydrogen, oxygen, nitrogen, and sulfur after the bacterial transformation of OM. The chemical complexity generated by bacterial metabolism provides new insights into the mechanisms that shape OM complexity.
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Affiliation(s)
- Yang Liu
- Institute for Advance Marine Research, China University of Geosciences, Guangzhou 511462, China
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China
- Institute of Marine Science and Technology, Shandong University, Qingdao 266237, China
| | - Chao Ma
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Jun Sun
- Institute for Advance Marine Research, China University of Geosciences, Guangzhou 511462, China
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China
- Corresponding author
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32
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Zhang DX, Wang MY, Lin WB, Qu S, Ji L, Xu C, Kan H, Dong K. Recent advances in emerging application of functional materials in sample pretreatment methods for liquid chromatography-mass spectrometry analysis of plant growth regulators: A mini-review. J Chromatogr A 2023; 1704:464130. [PMID: 37302252 DOI: 10.1016/j.chroma.2023.464130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 05/04/2023] [Accepted: 06/03/2023] [Indexed: 06/13/2023]
Abstract
Plant growth regulators (PGRs) are a class of small molecular compounds, which can remarkably affect the physiological process of plants. The complex plant matrix along with a wide polarity range and unstable chemical properties of PGRs hinder their trace analysis. In order to obtain a reliable and accurate result, a sample pretreatment process must be carried out, including eliminating the interference of the matrix effect and pre-concentrating the analytes. In recent years, the research of functional materials in sample pretreatment has experienced rapid growth. This review comprehensively overviews recent development in functional materials covering one-dimensional materials, two-dimensional materials, and three-dimensional materials applied in the pretreatment of PGRs before liquid chromatography-mass spectrometry (LC-MS) analysis. Besides, the advantages and limitations of the above functionalized enrichment materials are discussed, and their future trends have been prospected. The work could be helpful to bring new insights for researchers engaged in functional materials in sample pretreatment of PGRs based on LC-MS.
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Affiliation(s)
- Dong-Xue Zhang
- College of Chinese Medicinal Materials, Jilin Agricultural University, 2888 Xincheng Street, Changchun 130118, Jilin, China
| | - Ming-Yue Wang
- College of Chinese Medicinal Materials, Jilin Agricultural University, 2888 Xincheng Street, Changchun 130118, Jilin, China
| | - Wen-Bo Lin
- College of Chinese Medicinal Materials, Jilin Agricultural University, 2888 Xincheng Street, Changchun 130118, Jilin, China
| | - Shuai Qu
- Biology Institute of Jilin province, 1244 Qianjin Street, Changchun 130012, Jilin, China
| | - Li Ji
- College of Chinese Medicinal Materials, Jilin Agricultural University, 2888 Xincheng Street, Changchun 130118, Jilin, China
| | - Chen Xu
- College of Chinese Medicinal Materials, Jilin Agricultural University, 2888 Xincheng Street, Changchun 130118, Jilin, China
| | - Hong Kan
- College of Chinese Medicinal Materials, Jilin Agricultural University, 2888 Xincheng Street, Changchun 130118, Jilin, China.
| | - Kai Dong
- College of Chinese Medicinal Materials, Jilin Agricultural University, 2888 Xincheng Street, Changchun 130118, Jilin, China.
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33
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Thoben C, Raddatz CR, Tataroglu A, Kobelt T, Zimmermann S. How to Improve the Resolving Power of Compact Electrospray Ionization Ion Mobility Spectrometers. Anal Chem 2023; 95:8277-8283. [PMID: 37192335 DOI: 10.1021/acs.analchem.3c00471] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Every drift tube ion mobility spectrometer (IMS) has an optimum drift voltage to reach maximum resolving power. This optimum depends, among other things, on the temporal and spatial width of the injected ion packet and the pressure within the IMS. A reduction of the spatial width of the injected ion packet leads to improved resolving power, higher peak amplitudes when operating the IMS at optimum resolving power, and thus a better signal-to-noise ratio despite the reduced number of injected ions. Hereby, the performance of electrospray ionization (ESI)-IMS can be considerably improved. By setting the ion shutter opening time to just 5 μs and slightly increasing the pressure, a high resolving power RP > 150 can be achieved with a given drift length of just 75 mm. At such high resolving power, even a mixture of the herbicides isoproturon and chlortoluron having similar ion mobility can be well separated despite short drift length.
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Affiliation(s)
- Christian Thoben
- Institute of Electrical Engineering and Measurement Technology, Department of Sensors and Measurement Technology, Leibniz University Hannover, Appelstraße 9A, 30167 Hannover, Germany
| | - Christian-Robert Raddatz
- Institute of Electrical Engineering and Measurement Technology, Department of Sensors and Measurement Technology, Leibniz University Hannover, Appelstraße 9A, 30167 Hannover, Germany
| | - Aykut Tataroglu
- Institute of Electrical Engineering and Measurement Technology, Department of Sensors and Measurement Technology, Leibniz University Hannover, Appelstraße 9A, 30167 Hannover, Germany
| | - Tim Kobelt
- Institute of Electrical Engineering and Measurement Technology, Department of Sensors and Measurement Technology, Leibniz University Hannover, Appelstraße 9A, 30167 Hannover, Germany
| | - Stefan Zimmermann
- Institute of Electrical Engineering and Measurement Technology, Department of Sensors and Measurement Technology, Leibniz University Hannover, Appelstraße 9A, 30167 Hannover, Germany
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34
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Krmar J, Stojadinović LT, Đurkić T, Protić A, Otašević B. Predicting liquid chromatography-electrospray ionization/mass spectrometry signal from the structure of model compounds and experimental factors; case study of aripiprazole and its impurities. J Pharm Biomed Anal 2023; 233:115422. [PMID: 37150055 DOI: 10.1016/j.jpba.2023.115422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 04/24/2023] [Accepted: 04/24/2023] [Indexed: 05/09/2023]
Abstract
A priori estimation of analyte response is crucial for the efficient development of liquid chromatography-electrospray ionization/mass spectrometry (LC-ESI/MS) methods, but remains a demanding task given the lack of knowledge about the factors affecting the experimental outcome. In this research, we address the challenge of discovering the interactive relationship between signal response and structural properties, method parameters and solvent-related descriptors throughout an approach featuring quantitative structure-property relationship (QSPR) and design of experiments (DoE). To systematically investigate the experimental domain within which QSPR prediction should be undertaken, we varied LC and instrumental factors according to the Box-Behnken DoE scheme. Seven compounds, including aripiprazole and its impurities, were subjected to 57 different experimental conditions, resulting in 399 LC-ESI/MS data endpoints. To obtain a more standard distribution of the measured response, the peak areas were log-transformed before modeling. QSPR predictions were made using features selected by Genetic Algorithm (GA) and providing Gradient Boosted Trees (GBT) with training data. Proposed model showed satisfactory performance on test data with a RMSEP of 1.57 % and a of 96.48 %. This is the first QSPR study in LC-ESI/MS that provided a holistic overview of the analyte's response behavior across the experimental and chemical space. Since intramolecular electronic effects and molecular size were given great importance, the GA-GBT model improved the understanding of signal response generation of model compounds. It also highlighted the need to fine-tune the parameters affecting desolvation and droplet charging efficiency.
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Affiliation(s)
- Jovana Krmar
- Department of Drug Analysis, University of Belgrade-Faculty of Pharmacy, Vojvode Stepe 450, 11221 Belgrade, Serbia
| | | | - Tatjana Đurkić
- Department of Environmental Engineering, University of Belgrade-Faculty of Technology and Metallurgy, Karnegijeva 4, 11000 Belgrade, Serbia
| | - Ana Protić
- Department of Drug Analysis, University of Belgrade-Faculty of Pharmacy, Vojvode Stepe 450, 11221 Belgrade, Serbia
| | - Biljana Otašević
- Department of Drug Analysis, University of Belgrade-Faculty of Pharmacy, Vojvode Stepe 450, 11221 Belgrade, Serbia.
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Thoben C, Hartner NT, Hitzemann M, Raddatz CR, Eckermann M, Belder D, Zimmermann S. Regarding the Influence of Additives and Additional Plasma-Induced Chemical Ionization on Adduct Formation in ESI/IMS/MS. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023; 34:857-868. [PMID: 37052511 PMCID: PMC10161231 DOI: 10.1021/jasms.2c00348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Ion mobility spectrometers (IMS) separate ions based on their ion mobility, which depends mainly on collision cross-section, mass, and charge of the ions. However, the performance is often hampered in electrospray ionization (ESI) by the appearance of multiple ion mobility peaks in the spectrum for the same analyte due to clustering and additional sodium adducts. In this work, we investigate the influence of solvents and buffer additives on the detected ion mobility peaks using ESI. Additionally, we investigate the effects of an additional chemical ionization (CI) induced by plasma ionization on the ions formed by electrospray. For this purpose, we coupled our high-resolution IMS with a resolving power of Rp = 100 to a time-of-flight mass spectrometer. Depending on the analyte and the chosen additives, the ionization process can be influenced during the electrospray process. For the herbicide isoproturon, the addition of 5 mM sodium acetate results in the formation of the sodium adduct [M + Na]+, which is reflected in the ion mobility K0 of 1.22 cm2/(V·s). In contrast, the addition of 5 mM ammonium acetate yields the protonated species [M + H]+ and a correspondingly higher K0 of 1.29 cm2/(V·s). In some cases, as with the herbicide pyrimethanil, the addition of sodium acetate can completely suppress ionizations. By carefully choosing the solvent additive for ESI-IMS or additional CI, the formation of different ion mobility peaks can be observed. This can facilitate the assignment of ions to ion mobility peaks using IMS as a compact, stand-alone instrument, e.g., for on-site analysis.
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Affiliation(s)
- Christian Thoben
- Leibniz University Hannover, Institute of Electrical Engineering and Measurement Technology, Department of Sensors and Measurement Technology, Appelstr. 9A, 30167 Hannover, Germany
| | - Nora T Hartner
- Leipzig University, Institute of Analytical Chemistry, Linnéstraße 3, 04103 Leipzig, Germany
| | - Moritz Hitzemann
- Leibniz University Hannover, Institute of Electrical Engineering and Measurement Technology, Department of Sensors and Measurement Technology, Appelstr. 9A, 30167 Hannover, Germany
| | - Christian-Robert Raddatz
- Leibniz University Hannover, Institute of Electrical Engineering and Measurement Technology, Department of Sensors and Measurement Technology, Appelstr. 9A, 30167 Hannover, Germany
| | - Manuel Eckermann
- Leibniz University Hannover, Institute of Electrical Engineering and Measurement Technology, Department of Sensors and Measurement Technology, Appelstr. 9A, 30167 Hannover, Germany
| | - Detlev Belder
- Leipzig University, Institute of Analytical Chemistry, Linnéstraße 3, 04103 Leipzig, Germany
| | - Stefan Zimmermann
- Leibniz University Hannover, Institute of Electrical Engineering and Measurement Technology, Department of Sensors and Measurement Technology, Appelstr. 9A, 30167 Hannover, Germany
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36
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Allen N, Li H, Wang T, Li A. Gigaohm and Teraohm Resistors in Femtoamp and Picoamp Electrospray Ionization. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023; 34:913-921. [PMID: 37052599 DOI: 10.1021/jasms.2c00369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The femtoamp electrospray ionization (femtoESI) mode has been shown to exhibit unique characteristics that may facilitate ionization efficiency studies and experiments requiring low ion beam flux. Investigation of femtoESI was hindered by a tiny, applied voltage window of 10-100 V, beyond which ionization currents quickly jumped to nanoamps. This window was difficult to locate because the exact onset voltage fluctuates due to variations in ion source alignments. Large resistors (0.1-100 TΩ) in series effectively expanded the femtoESI applied voltage range, up to 1400 V. By swapping resistors, rapid alternation allows for the comparison of both ESI modes under the same alignment. In peptide mixtures, analytes with lower surface activity are suppressed in the nanoESI mode whereas the femtoESI mode shows signal enhancement of less surface-active species. For protein solutions, there is little change in the charge states generated but the femtoESI mode does show a decrease in the average charge state of protein peaks. Peptides and proteins analyzed in the femtoESI mode also tend to generate higher intensity sodiated peaks over protonated peaks at specific charge states compared with nanoESI mode operation.
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Affiliation(s)
- Nicholas Allen
- Department of Chemistry, University of New Hampshire, 23 Academic Way, Durham, New Hampshire 03824, United States
| | - Huishan Li
- Department of Chemistry, University of New Hampshire, 23 Academic Way, Durham, New Hampshire 03824, United States
| | - Taoqing Wang
- Department of Chemistry, University of New Hampshire, 23 Academic Way, Durham, New Hampshire 03824, United States
| | - Anyin Li
- Department of Chemistry, University of New Hampshire, 23 Academic Way, Durham, New Hampshire 03824, United States
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37
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Mostafa ME, Hayes MM, Grinias JP, Bythell BJ, Edwards JL. Supercritical Fluid Nanospray Mass Spectrometry: II. Effects on Ionization. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023. [PMID: 37097105 DOI: 10.1021/jasms.2c00372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Nanospraying supercritical fluids coupled to a mass spectrometer (nSF-MS) using a 90% supercritical fluid CO2 carrier (sCO2) has shown an enhanced desolvation compared to traditional liquid eluents. Capillaries of 25, 50, and 75 μm internal diameter (i.d.) with pulled emitter tips provided high MS detection sensitivity. Presented here is an evaluation of the effect of proton affinity, hydrophobicity, and nanoemitter tip size on the nSF-MS signal. This was done using a set of primary, secondary, tertiary, and quaternary amines with butyl, hexyl, octyl, and decyl chains as analytes. Each amine class was analyzed individually to evaluate hydrophobicity and proton affinity effects on signal intensity. The system has shown a mass sensitive detection on a linear dynamic range of 0.1-100 μM. Results indicate that hydrophobicity has a larger effect on the signal response than proton affinity. Nanospraying a mixture of all amine classes using the 75 μm emitter has shown a quaternary amine signal not suppressed by competing analytes. Competing ionization was observed for primary, secondary, and tertiary amines. The 75 and 50 μm emitters demonstrated increased signal with increasing hydrophobicity. Surprisingly, the 25 μm i.d. emitter yielded a signal decrease as the alkyl chain length increased, contrary to conventional understanding. Nanospraying the evaporative fluid in a sub-500 nm emitter likely resulted in differences in the ionization mechanism. Results suggest that 90% sCO2 with 9.99% methanol and 0.01% formic acid yielded fast desolvation, high ionization efficiency, and low matrix effect, which could benefit complex biological matrix analysis.
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Affiliation(s)
- Mahmoud Elhusseiny Mostafa
- Department of Chemistry and Biochemistry, Saint Louis University, 3501 Laclede Ave., St. Louis, Missouri 63103, United States
| | - Madisyn M Hayes
- Department of Chemistry and Biochemistry, Ohio University, 307 Chemistry Building, Athens, Ohio 45701, United States
| | - James P Grinias
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Rd., Glassboro, New Jersey 08028, United States
| | - Benjamin J Bythell
- Department of Chemistry and Biochemistry, Ohio University, 307 Chemistry Building, Athens, Ohio 45701, United States
| | - James L Edwards
- Department of Chemistry and Biochemistry, Saint Louis University, 3501 Laclede Ave., St. Louis, Missouri 63103, United States
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Sedláčková S, Hubálek M, Vrkoslav V, Blechová M, Kozlík P, Cvačka J. Positive Effect of Acetylation on Proteomic Analysis Based on Liquid Chromatography with Atmospheric Pressure Chemical Ionization and Photoionization Mass Spectrometry. Molecules 2023; 28:molecules28093711. [PMID: 37175121 PMCID: PMC10180487 DOI: 10.3390/molecules28093711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 04/14/2023] [Accepted: 04/21/2023] [Indexed: 05/15/2023] Open
Abstract
A typical bottom-up proteomic workflow comprises sample digestion with trypsin, separation of the hydrolysate using reversed-phase HPLC, and detection of peptides via electrospray ionization (ESI) tandem mass spectrometry. Despite the advantages and wide usage of protein identification and quantification, the procedure has limitations. Some domains or parts of the proteins may remain inadequately described due to inefficient detection of certain peptides. This study presents an alternative approach based on sample acetylation and mass spectrometry with atmospheric pressure chemical ionization (APCI) and atmospheric pressure photoionization (APPI). These ionizations allowed for improved detection of acetylated peptides obtained via chymotrypsin or glutamyl peptidase I (Glu-C) digestion. APCI and APPI spectra of acetylated peptides often provided sequence information already at the full scan level, while fragmentation spectra of protonated molecules and sodium adducts were easy to interpret. As demonstrated for bovine serum albumin, acetylation improved proteomic analysis. Compared to ESI, gas-phase ionizations APCI and APPI made it possible to detect more peptides and provide better sequence coverages in most cases. Importantly, APCI and APPI detected many peptides which passed unnoticed in the ESI source. Therefore, analytical methods based on chymotrypsin or Glu-C digestion, acetylation, and APPI or APCI provide data complementary to classical bottom-up proteomics.
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Affiliation(s)
- Simona Sedláčková
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo Náměstí 542/2, 16000 Prague, Czech Republic
- Department of Analytical Chemistry, Faculty of Science, Charles University, Hlavova 2030/8, 12800 Prague, Czech Republic
| | - Martin Hubálek
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo Náměstí 542/2, 16000 Prague, Czech Republic
| | - Vladimír Vrkoslav
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo Náměstí 542/2, 16000 Prague, Czech Republic
| | - Miroslava Blechová
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo Náměstí 542/2, 16000 Prague, Czech Republic
| | - Petr Kozlík
- Department of Analytical Chemistry, Faculty of Science, Charles University, Hlavova 2030/8, 12800 Prague, Czech Republic
| | - Josef Cvačka
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo Náměstí 542/2, 16000 Prague, Czech Republic
- Department of Analytical Chemistry, Faculty of Science, Charles University, Hlavova 2030/8, 12800 Prague, Czech Republic
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Willemse L, Terburgh K, Louw R. A ketogenic diet alters mTOR activity, systemic metabolism and potentially prevents collagen degradation associated with chronic alcohol consumption in mice. Metabolomics 2023; 19:43. [PMID: 37076659 PMCID: PMC10115735 DOI: 10.1007/s11306-023-02006-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 03/31/2023] [Indexed: 04/21/2023]
Abstract
INTRODUCTION A ketogenic diet (KD), which is a high fat, low carbohydrate diet has been shown to inhibit the mammalian target of rapamycin (mTOR) pathway and alter the redox state. Inhibition of the mTOR complex has been associated with the attenuation and alleviation of various metabolic and- inflammatory diseases such as neurodegeneration, diabetes, and metabolic syndrome. Various metabolic pathways and signalling mechanisms have been explored to assess the therapeutic potential of mTOR inhibition. However, chronic alcohol consumption has also been reported to alter mTOR activity, the cellular redox- and inflammatory state. Thus, a relevant question that remains is what effect chronic alcohol consumption would have on mTOR activity and overall metabolism during a KD-based intervention. OBJECTIVES The aim of this study was to evaluate the effect of alcohol and a KD on the phosphorylation of the mTORC1 target p70S6K, systemic metabolism as well as the redox- and inflammatory state in a mouse model. METHODS Mice were fed either a control diet with/without alcohol or a KD with/without alcohol for three weeks. After the dietary intervention, samples were collected and subjected towards western blot analysis, multi-platform metabolomics analysis and flow cytometry. RESULTS Mice fed a KD exhibited significant mTOR inhibition and reduction in growth rate. Alcohol consumption alone did not markedly alter mTOR activity or growth rate but moderately increased mTOR inhibition in mice fed a KD. In addition, metabolic profiling showed alteration of several metabolic pathways as well as the redox state following consumption of a KD and alcohol. A KD was also observed to potentially prevent bone loss and collagen degradation associated with chronic alcohol consumption, as indicated by hydroxyproline metabolism. CONCLUSION This study sheds light on the influence that a KD alongside alcohol intake can exert on not just mTOR, but also their effect on metabolic reprogramming and the redox state.
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Affiliation(s)
- Luciano Willemse
- Human Metabolomics, Faculty of Natural and Agricultural Sciences, North-West University (Potchefstroom Campus), Private Bag X6001, Potchefstroom, South Africa
| | - Karin Terburgh
- Human Metabolomics, Faculty of Natural and Agricultural Sciences, North-West University (Potchefstroom Campus), Private Bag X6001, Potchefstroom, South Africa
| | - Roan Louw
- Human Metabolomics, Faculty of Natural and Agricultural Sciences, North-West University (Potchefstroom Campus), Private Bag X6001, Potchefstroom, South Africa.
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40
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Stepanovic S, Hopfgartner G. Predicting Preferences for Adduct Formation in Electrospray Ionization: The Case Study of Succinic Acid. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023; 34:562-569. [PMID: 36944084 DOI: 10.1021/jasms.2c00297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
A simple theoretical approach is developed that can be used to predict the preference of ion adduct formation (with alkali Li+, Na+, K+ and alkaline earth Ca2+, Mg2+ metals) in electrospray ionization mass spectrometry (ESI-MS) of succinic acid, associated with several protonation/deprotonation equilibria. The applied strategy consists of using a vacuum environment as well as both implicit and explicit solvation of reactive sites and density functional theory as the method of choice. These distinct levels of theory mimic the smooth transition between the condensed environment and free ion in the gas phase. Good correlation between the Gibbs free energies for protonation/adduct formation processes with peak observation in the obtained mass spectra provide insight into the physical basis behind adduct preference and selectivity. This signifies the relationship between microscopic interactions, ionization efficiency, and types of ions that reach the detector.
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Affiliation(s)
- Stepan Stepanovic
- Life Sciences Mass Spectrometry, Department of Inorganic and Analytical Chemistry, University of Geneva, CH-1211 Geneva 4 Switzerland
- Institute of Chemistry, Technology and Metallurgy, University of Belgrade, Njegoševa 12, 11000 Belgrade, Serbia
| | - Gérard Hopfgartner
- Life Sciences Mass Spectrometry, Department of Inorganic and Analytical Chemistry, University of Geneva, CH-1211 Geneva 4 Switzerland
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41
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Brookhart A, Arora M, McCullagh M, Wilson ID, Plumb RS, Vissers JP, Tanna N. Understanding mobile phase buffer composition and chemical structure effects on electrospray ionization mass spectrometry response. J Chromatogr A 2023; 1696:463966. [PMID: 37054638 DOI: 10.1016/j.chroma.2023.463966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2023] [Revised: 04/01/2023] [Accepted: 04/03/2023] [Indexed: 04/15/2023]
Abstract
Mobile phase selection is of critical importance in liquid chromatography - mass spectrometry (LC-MS) based studies, since it affects retention, chromatographic selectivity, ionization, limits of detection and quantification, and linear dynamic range. Generalized LC-MS mobile phase selection criteria, suitable for a broad class of chemical compounds, do not exist thus far. Here we have performed a large-scale qualitative assessment of the effect of solvent composition used for reversed-phase LC separations on electrospray ionization (ESI) response for 240 small molecular weight drugs, representing various chemical compound classes. Of these 240 analytes 224 were detectable using ESI. The main chemical structural features affecting ESI response were found to all be surface area or surface charge-related. Mobile phase composition was found to be less differentiating, although for some compounds a pH effect was noted. Unsurprisingly, chemical structure was found to be the dominant factor for ESI response for the majority of the investigated analytes, representing about 85% of the replicating detectable complement of the sample data set. A weak correlation between ESI response and structure complexity was observed. Solvents based on isopropanol, and those containing phosphoric or di- and trifluoracetic acids, performed relatively poorly in terms of chromatographic or ESI response, whilst the best performing 'generic' LC solvents were based on methanol, acetonitrile using formic acid and ammonium acetate as buffer components, consistent with current practice in many laboratories.
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Affiliation(s)
- Allison Brookhart
- Department of Biochemistry and Molecular Biology, University of Massachusetts Amherst, MA
| | - Mahika Arora
- Manning College of Information and Computer Sciences, University of Massachusetts Amherst, MA
| | | | - Ian D Wilson
- Computational & Systems Medicine, Department of Metabolism, Digestion and Reproduction, Imperial College, United Kingdom
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42
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Parise RJ, Dassanayake DR, Levis RJ. Pulse Duration Effects on Solution-Phase Protein Desorption in Laser Electrospray Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023; 34:701-709. [PMID: 36947866 DOI: 10.1021/jasms.2c00362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
The effect of laser pulse duration on the ablation of aqueous myoglobin is investigated using laser electrospray mass spectrometry (LEMS). Pulse durations of 55 femtoseconds (fs), 56 piscoseconds (ps), and 10 nanoseconds (ns) were used to ablate aqueous myoglobin from stainless-steel and quartz substrates. The integrated signal intensity of myoglobin increases with decreasing pulse duration for both substrates. Laser-induced thermal effects are assessed by the relative amount of solvent adduction and number of phosphate moieties adducted to myoglobin by each laser pulse duration. The mass spectra for 55 fs vaporization shows myoglobin with appreciable solvent and phosphate adduction and baseline elevation. The mass spectra for 10 ns ablation have minimal adduction and limited baseline elevation. Heat-induced conformation changes in myoglobin were used to measure the amount of thermal energy deposited by each laser pulse duration. Ablation using the 55 fs pulse revealed the highest ratio of unfolded to folded myoglobin in comparison to the 56 ps and 10 ns measurements due to increased droplet lifetime and consequent interaction with the acid in the electrospray solvent. Collisional activation and heated capillary temperature were employed to reduce the droplet lifetime and demonstrate that fs ablation preserves approximately 2 times more myoglobin folded conformation in comparison to ps and ns pulses.
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Affiliation(s)
- Rachel J Parise
- Department of Chemistry, Temple University, 1901 North 13th Street, Philadelphia, Pennsylvania 19122, United States
- Center for Advanced Photonics Research, Temple University, 1901 North 13th Street, Philadelphia, Pennsylvania 19122, United States
| | - Dilini R Dassanayake
- Department of Chemistry, Temple University, 1901 North 13th Street, Philadelphia, Pennsylvania 19122, United States
- Center for Advanced Photonics Research, Temple University, 1901 North 13th Street, Philadelphia, Pennsylvania 19122, United States
| | - Robert J Levis
- Department of Chemistry, Temple University, 1901 North 13th Street, Philadelphia, Pennsylvania 19122, United States
- Center for Advanced Photonics Research, Temple University, 1901 North 13th Street, Philadelphia, Pennsylvania 19122, United States
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43
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Xu AM, Tang LC, Jovanovic M, Regev O. A high-throughput approach reveals distinct peptide charging behaviors in electrospray ionization mass spectrometry. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.31.535171. [PMID: 37066236 PMCID: PMC10103939 DOI: 10.1101/2023.03.31.535171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Electrospray ionization is a powerful and prevalent technique used to ionize analytes in mass spectrometry. The distribution of charges that an analyte receives (charge state distribution, CSD) is an important consideration for interpreting mass spectra. However, due to an incomplete understanding of the ionization mechanism, the analyte properties that influence CSDs are not fully understood. Here, we employ a machine learning-based high-throughput approach and analyze CSDs of hundreds of thousands of peptides. Interestingly, half of the peptides exhibit charges that differ from what one would naively expect (number of basic sites). We find that these peptides can be classified into two regimes-undercharging and overcharging-and that these two regimes display markedly different charging characteristics. Strikingly, peptides in the overcharging regime show minimal dependence on basic site count, and more generally, the two regimes exhibit distinct sequence determinants. These findings highlight the rich ionization behavior of peptides and the potential of CSDs for enhancing peptide identification.
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Affiliation(s)
- Allyn M. Xu
- Department of Mathematics, Courant Institute of Mathematical Sciences, New York University, NY, USA
| | - Lauren C. Tang
- Department of Biological Sciences, Columbia University, New York, NY, USA
| | - Marko Jovanovic
- Department of Biological Sciences, Columbia University, New York, NY, USA
| | - Oded Regev
- Computer Science Department, Courant Institute of Mathematical Sciences, New York University, NY, USA
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44
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Zhou Z, Fu QL, Fujii M, Waite TD. Complementary Elucidation of the Molecular Characteristics of Groundwater Dissolved Organic Matter Using Ultrahigh-Resolution Mass Spectrometry Coupled with Negative- and Positive-Ion Electrospray Ionization. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:4690-4700. [PMID: 36905367 DOI: 10.1021/acs.est.2c08816] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
The formula assignment of the Fourier transform ion cyclotron resonance mass spectrometry coupled with positive-ion electrospray ionization [ESI(+)-FT-ICR MS] is challenging because of the extensive occurrence of adducts. However, there is a paucity of automated formula assignment methods for ESI(+)-FT-ICR MS spectra. The novel automated formula assignment algorithm for ESI(+)-FT-ICR MS spectra developed herein has been applied to elucidate the composition of dissolved organic matter (DOM) in groundwater during air-induced ferrous [Fe(II)] oxidation. The ESI(+)-FT-ICR MS spectra of groundwater DOM were profoundly impacted by [M + Na]+ adducts and, to a lesser extent, [M + K]+ adducts. Oxygen-poor and N-containing compounds were frequently detected when the FT-ICR MS was operated in the ESI(+) mode, while the components with higher carbon oxidation states were preferentially ionized in the negative-ion electrospray ionization [ESI(-)] mode. Values for the difference between double-bond equivalents and the number of oxygen atoms from -13 to 13 are proposed for the formula assignment of the ESI(+)-FT-ICR MS spectra of aquatic DOM. Furthermore, for the first time, the Fe(II)-mediated formation of highly toxic organic iodine species was reported in groundwater rich in Fe(II), iodide, and DOM. The results of this study not only shed light on the further algorithm development for comprehensive characterization of DOM by ESI(-)-FT-ICR MS and ESI(+)-FT-ICR MS but also highlight the importance of appropriate treatment of specific groundwater prior to use.
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Affiliation(s)
- Ziqi Zhou
- School of Environmental Studies, China University of Geosciences, Wuhan 430078, China
- UNSW Water Research Centre, School of Civil and Environmental Engineering, The University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Qing-Long Fu
- School of Environmental Studies, China University of Geosciences, Wuhan 430078, China
| | - Manabu Fujii
- Department of Civil and Environmental Engineering, Tokyo Institute of Technology, 2-12-1, Ookayama, Meguro-Ku, Tokyo 152-8550, Japan
| | - T David Waite
- UNSW Water Research Centre, School of Civil and Environmental Engineering, The University of New South Wales, Sydney, New South Wales 2052, Australia
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Huntley AP, Hollerbach AL, Prabhakaran A, Garimella SV, Giberson CM, Norheim RV, Smith RD, Ibrahim YM. Development of a Structure for Lossless Ion Manipulations (SLIM) High Charge Capacity Array of Traps. Anal Chem 2023; 95:4446-4453. [PMID: 36820625 PMCID: PMC10634340 DOI: 10.1021/acs.analchem.2c05025] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
Enhancing the sensitivity of low-abundance ions in a complex mixture without sacrificing measurement throughput is highly desirable. This work demonstrates a way to greatly improve the sensitivity of ion mobility (IM)-selected ions by accumulating them in an array of high-capacity ion traps located inside a novel structures for lossless ion manipulations ion mobility spectrometer (SLIM-IMS) module. The array of ion traps used in this work consisted of seven independently controllable traps. Each trap was 386 mm long and possessed a charge capacity of ∼4.5 × 108 charges, with a linear range extending to ∼2.5 × 108 charges. Each ion trap could be used to extract a peak (or ions over a mobility range) from an ion mobility separation based on arrival time. Ions could be stored without losses for long times (>100 s) and then released all at once or one trap at a time. It was possible to accumulate large ion populations by extracting and storing ions over repeated IM separations. Enrichment of up to seven individual ion distributions could be performed using the seven independently controllable ion traps. Additionally, the ion trapping process effectively compressed ion populations into narrow peaks, which provides a greatly improved basis for subsequent ion manipulations. The array of high charge capacity ion traps provides a flexible addition to SLIM and a powerful tool for IMS-MS applications requiring high sensitivity.
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Affiliation(s)
- Adam P. Huntley
- Biological Sciences Division, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington, 99354, United States
| | - Adam L. Hollerbach
- Biological Sciences Division, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington, 99354, United States
| | - Aneesh Prabhakaran
- Biological Sciences Division, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington, 99354, United States
| | - Sandilya V.B. Garimella
- Biological Sciences Division, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington, 99354, United States
| | - Cameron M. Giberson
- Biological Sciences Division, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington, 99354, United States
| | - Randolph V. Norheim
- Biological Sciences Division, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington, 99354, United States
| | - Richard D. Smith
- Biological Sciences Division, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington, 99354, United States
| | - Yehia M. Ibrahim
- Biological Sciences Division, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington, 99354, United States
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46
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Schleicher S, O'Connor G, Mischnick P. Comparing 13C methyl and deuterated methyl isotopic labeling for the quantification of methyl cellulose patterns using mass spectrometry. Anal Bioanal Chem 2023; 415:1817-1828. [PMID: 36867199 PMCID: PMC10050035 DOI: 10.1007/s00216-023-04622-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 02/08/2023] [Accepted: 02/20/2023] [Indexed: 03/04/2023]
Abstract
The methyl substitution along and among the polymer chains of methyl cellulose (MC) is commonly analyzed by ESI-MS after perdeuteromethylation of the free-OH groups and partial hydrolysis to cello-oligosaccharides (COS). This method requires a correct quantification of the molar ratios of the constituents belonging to a particular degree of polymerization (DP). However, isotopic effects are most pronounced for H/D since their mass difference is 100%. Therefore, we investigated whether more precise and accurate results could be obtained for the methyl distribution of MC by MS of 13CH3 instead of CD3-etherified O-Me-COS. Internal isotope labeling with 13CH3 makes the COS of each DP chemically and physically much more similar, reducing mass fractionation effects, but at the same time requires more complex isotopic correction for evaluation. Results from syringe pump infusion ESI-TOF-MS with 13CH3 and CD3 as isotope label were equal. However, in the case of LC-MS with a gradient system, 13CH3 was superior to CD3. In the case of CD3, the occurrence of a partial separation of the isotopologs of a particular DP resulted in slight distortion of the methyl distribution since the signal response is significantly dependent on the solvent composition. Isocratic LC levels this problem, but one particular eluent-composition is not sufficient for a series of oligosaccharides with increasing DP due to peak broadening. In summary, 13CH3 is more robust to determine the methyl distribution of MCs. Both syringe pump and gradient-LC-MS measurements are possible, and the more complex isotope correction is not a disadvantage.
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Affiliation(s)
- Sarah Schleicher
- Institute of Food Chemistry, Technische Universität Braunschweig, Schleinitzstr. 20, 38106, Braunschweig, Germany.
| | - Gavin O'Connor
- Department of Biochemistry, Physikalisch-Technische-Bundesanstalt, Bundesallee 100, 38116, Braunschweig, Germany
- Department of Biochemistry and Bioinformatics, Technische Universität Braunschweig, Rebenring 56, 38106, Braunschweig, Germany
| | - Petra Mischnick
- Institute of Food Chemistry, Technische Universität Braunschweig, Schleinitzstr. 20, 38106, Braunschweig, Germany.
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47
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Scrosati PM, Konermann L. Atomistic Details of Peptide Reversed-Phase Liquid Chromatography from Molecular Dynamics Simulations. Anal Chem 2023; 95:3892-3900. [PMID: 36745777 DOI: 10.1021/acs.analchem.2c05667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Peptide separations by reversed-phase liquid chromatography (RPLC) are an integral part of bottom-up proteomics. These separations typically employ C18 columns with water/acetonitrile gradient elution in the presence of formic acid. Despite the widespread use of such workflows, the exact nature of peptide interactions with the stationary and mobile phases is poorly understood. Here, we employ microsecond molecular dynamics (MD) simulations to uncover details of peptide RPLC. We examined two tryptic peptides, a hydrophobic and a hydrophilic species, in a slit pore lined with C18 chains that were grafted onto SiO2 support. Our simulations explored peptide trapping, followed by desorption and elution. Trapping in an aqueous mobile phase was initiated by C18 contacts with Lys butyl moieties. This was followed by extensive anchoring of nonpolar side chains (Leu/Ile/Val) in the C18 layer. Exposure to water/acetonitrile triggered peptide desorption in a stepwise fashion; charged sites close to the termini were the first to lift off, followed by the other residues. During water/acetonitrile elution, both peptides preferentially resided close to the pore center. The hydrophilic peptide exhibited no contacts with the stationary phase under these conditions. In contrast, the hydrophobic species underwent multiple transient Leu/Ile/Val binding interactions with C18 chains. These nonpolar interactions represent the foundation of differential peptide retention, in agreement with the experimental elution behavior of the two peptides. Extensive peptide/formate ion pairing was observed in water/acetonitrile, particularly at N-terminal sites. Overall, this work uncovers an unprecedented level of RPLC molecular details, paving the way for MD simulations as a future tool for improving retention prediction algorithms and for the design of novel column materials.
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Affiliation(s)
- Pablo M Scrosati
- Department of Chemistry, The University of Western Ontario, London, Ontario, N6A 5B7, Canada
| | - Lars Konermann
- Department of Chemistry, The University of Western Ontario, London, Ontario, N6A 5B7, Canada
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48
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Cost-Effective Simultaneous Determination of τ- and π-Methylhistidine in Dairy Bovine Plasma from Large Cohort Studies Using Hydrophilic Interaction Ultra-High Performance Liquid Chromatography Coupled to Tandem Mass Spectrometry. SEPARATIONS 2023. [DOI: 10.3390/separations10020144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023] Open
Abstract
The isomeric metabolites τ- and π-methylhistidine (formerly referred to as 3- and 1-methylhistidine) are known biomarkers for muscle protein breakdown and meat protein intake, frequently used in studies involving humans and animals. In the present study, we report the development and validation of a simple HILIC-MS/MS method for individual determination of τ-MH and π-MH in a large cohort of blood plasma samples from dairy cows. Their separate determination was achieved mainly through a mass spectrometry fragment ion study, which revealed that the two isomers exhibited distinct mass spectrometric behaviors at different collision energies. Chromatographic conditions were optimised to achieve better separation, minimizing inter-channel interference to less than 1% in both directions. A simple and effective sample clean-up method facilitated low laboratory manual workload. The analytical method was validated for the determination of τ-MH and π-MH in bovine plasma within a concentration range of 80 to 1600 μg/L and provided good linearity (>0.99 for both curves) and precision (<10%). Overall, the developed method enabled the determination of the two isomers in an efficient and economic-friendly manner suitable for large cohort bovine studies (involving hundreds to thousands of samples) mainly to provide data for statistical use.
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49
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Kale D, Kikul F, Phapale P, Beedgen L, Thiel C, Brügger B. Quantification of Dolichyl Phosphates Using Phosphate Methylation and Reverse-Phase Liquid Chromatography-High Resolution Mass Spectrometry. Anal Chem 2023; 95:3210-3217. [PMID: 36716239 PMCID: PMC9933046 DOI: 10.1021/acs.analchem.2c03623] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Dolichyl monophosphates (DolPs) are essential lipids in glycosylation pathways that are highly conserved across almost all domains of life. The availability of DolP is critical for all glycosylation processes, as these lipids serve as membrane-anchored building blocks used by various types of glycosyltransferases to generate complex post-translational modifications of proteins and lipids. The analysis of DolP species by reverse-phase liquid chromatography-mass spectrometry (RPLC-MS) remains a challenge due to their very low abundance and wide range of lipophilicities. Until now, a method for the simultaneous qualitative and quantitative assessment of DolP species from biological membranes has been lacking. Here, we describe a novel approach based on simple sample preparation, rapid and efficient trimethylsilyl diazomethane-dependent phosphate methylation, and RPLC-MS analysis for quantification of DolP species with different isoprene chain lengths. We used this workflow to selectively quantify DolP species from lipid extracts derived of Saccharomyces cerevisiae, HeLa, and human skin fibroblasts from steroid 5-α-reductase 3- congenital disorders of glycosylation (SRD5A3-CDG) patients and healthy controls. Integration of this workflow with global lipidomics analyses will be a powerful tool to expand our understanding of the role of DolPs in pathophysiological alterations of metabolic pathways downstream of HMG-CoA reductase, associated with CDGs, hypercholesterolemia, neurodegeneration, and cancer.
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Affiliation(s)
- Dipali Kale
- Heidelberg
University Biochemistry Center (BZH), 69120Heidelberg, Germany,Leibniz-Institut
für Analytische Wissenschaften-ISAS-e.V., 44139Dortmund, Germany,
| | - Frauke Kikul
- Heidelberg
University Biochemistry Center (BZH), 69120Heidelberg, Germany
| | - Prasad Phapale
- Leibniz-Institut
für Analytische Wissenschaften-ISAS-e.V., 44139Dortmund, Germany
| | - Lars Beedgen
- Centre
for Child and Adolescent Medicine, University
Hospital Heidelberg, 69120Heidelberg, Germany
| | - Christian Thiel
- Centre
for Child and Adolescent Medicine, University
Hospital Heidelberg, 69120Heidelberg, Germany
| | - Britta Brügger
- Heidelberg
University Biochemistry Center (BZH), 69120Heidelberg, Germany,
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50
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Du S, Jia H, Xu W, Zhai Y. Field-Gradient-Focusing Ion Guide for Enhanced Transfer Efficiency of Low-Mass Ions. Anal Chem 2023; 95:2079-2086. [PMID: 36632644 DOI: 10.1021/acs.analchem.2c05014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Efficient transmission of low-mass ions in a rough vacuum pressure region has always been a challenging issue in mass spectrometry (MS). In this study, a novel ion guide, namely, field-gradient-focusing ion guide (FGF-IG), was proposed to improve the transfer efficiency of ions, especially low-mass ions in a rough vacuum region. The FGF-IG has 12 electrodes whose surfaces gradually narrowed and tilted inward, and its electric field gradually varies from dodecapole (or multipole) to quadrupole along the ion transfer route. The field radius was gradually decreased from 6 to 2 mm in the multipole region (65 mm in length) and finally remained unchanged as 2 mm in the quadrupole region (20 mm in length). By integrating into a miniature mass spectrometer (mini-MS) with a continuous atmospheric pressure interface, this ion guide was optimized in terms of inlet capillary position, radio frequency amplitude, and direct current voltage applied on it. Results showed that a reduced low-mass discrimination effect and improved efficiency of simultaneously transferring mid and low m/z ions were achieved for FGF-IG compared with a conventional ion funnel. Under optimized conditions, a limit of detection of 1 ng/mL was obtained for both reserpine (m/z 609) and arginine (m/z 175) ions by integrating FGF-IG into the mini-MS. The sensitivity of smaller arginine ions using FGF-IG was enhanced by ∼10 times than that obtained using the conventional ion funnel (10 ng/mL) in comparative experiments. The idea of smooth transfer from dodecapole to quadrupole fields could be extended to other multipole fields, as well as in lab-scale MS instruments.
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Affiliation(s)
- Shiyu Du
- School of Life Science, Beijing Institute of Technology, Beijing 100081, China
| | - Heyuan Jia
- School of Life Science, Beijing Institute of Technology, Beijing 100081, China
| | - Wei Xu
- School of Life Science, Beijing Institute of Technology, Beijing 100081, China
- Institute of Engineering Medicine, Beijing Institute of Technology, Beijing 100081, China
| | - Yanbing Zhai
- Institute of Engineering Medicine, Beijing Institute of Technology, Beijing 100081, China
- School of Medical Technology, Beijing Institute of Technology, Beijing 100081, China
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