1
|
van Outersterp R, Oosterhout J, Gebhardt CR, Berden G, Engelke UFH, Wevers RA, Cuyckens F, Oomens J, Martens J. Targeted Small-Molecule Identification Using Heartcutting Liquid Chromatography-Infrared Ion Spectroscopy. Anal Chem 2023; 95:3406-3413. [PMID: 36735826 PMCID: PMC9933049 DOI: 10.1021/acs.analchem.2c04904] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Infrared ion spectroscopy (IRIS) can be used to identify molecular structures detected in mass spectrometry (MS) experiments and has potential applications in a wide range of analytical fields. However, MS-based approaches are often combined with orthogonal separation techniques, in many cases liquid chromatography (LC). The direct coupling of LC and IRIS is challenging due to the mismatching timescales of the two technologies: an IRIS experiment typically takes several minutes, whereas an LC fraction typically elutes in several seconds. To resolve this discrepancy, we present a heartcutting LC-IRIS approach using a setup consisting of two switching valves and two sample loops as an alternative to direct online LC-IRIS coupling. We show that this automated setup enables us to record multiple IR spectra for two LC-features from a single injection without degrading the LC-separation performance. We demonstrate the setup for application in drug metabolism research by recording six m/z-selective IR spectra for two drug metabolites from a single 2 μL sample of cell incubation extract. Additionally, we measure the IR spectra of two closely eluting diastereomeric biomarkers for the inborn error of metabolism pyridoxine-dependent epilepsy (PDE-ALDH7A1), which shows that the heartcutting LC-IRIS setup has good sensitivity (requiring ∼μL injections of ∼μM samples) and that the separation between closely eluting isomers is maintained. We envision applications in a range of research fields, where the identification of molecular structures detected by LC-MS is required.
Collapse
Affiliation(s)
- Rianne
E. van Outersterp
- Radboud
University, Institute for Molecules and Materials, FELIX Laboratory, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands
| | - Jitse Oosterhout
- Radboud
University, Institute for Molecules and Materials, FELIX Laboratory, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands
| | | | - Giel Berden
- Radboud
University, Institute for Molecules and Materials, FELIX Laboratory, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands
| | - Udo F. H. Engelke
- Department
of Laboratory Medicine, Translational Metabolic Laboratory, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Ron A. Wevers
- Department
of Laboratory Medicine, Translational Metabolic Laboratory, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Filip Cuyckens
- Drug
Metabolism & Pharmacokinetics, Janssen R&D, Beerse 2340, Belgium
| | - Jos Oomens
- Radboud
University, Institute for Molecules and Materials, FELIX Laboratory, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands,van’t
Hoff Institute for Molecular Sciences, University
of Amsterdam, 1098XH Amsterdam, The Netherlands
| | - Jonathan Martens
- Radboud
University, Institute for Molecules and Materials, FELIX Laboratory, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands,
| |
Collapse
|
2
|
Bomhardt K, Schneider P, Rohnke M, Gebhardt CR, Dürr M. Cluster-induced desorption/ionization mass spectrometry of highlighter ink: unambiguous identification of dyes and degradation processes based on fragmentation-free desorption. Analyst 2021; 147:333-340. [PMID: 34932048 DOI: 10.1039/d1an01588e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Highlighter inks were analyzed by means of soft Desorption/Ionization induced by Neutral SO2 clusters (DINeC) in combination with mass spectrometry (MS). The dye molecules of the different inks were directly desorbed from dots of ink drawn on arbitrary substrates. Fragmentation free spectra were observed and the dyes used in the dye mixtures of the different highlighter inks were unambiguously identified. The soft nature of cluster-induced desorption was used to investigate the decomposition of the dye molecules induced by either heat or UV-light. The two processes lead to different decomposition products which are clearly distinguished in the DINeC spectra. The two different degradation processes can thus be discriminated using DINeC-MS.
Collapse
Affiliation(s)
- Karolin Bomhardt
- Institut für Angewandte Physik and Zentrum für Materialforschung, Justus-Liebig-Universität Giessen, Heinrich-Buff-Ring 16, 35392 Giessen, Germany.
| | - Pascal Schneider
- Institut für Angewandte Physik and Zentrum für Materialforschung, Justus-Liebig-Universität Giessen, Heinrich-Buff-Ring 16, 35392 Giessen, Germany.
| | - Marcus Rohnke
- Physikalisch-Chemisches Institut and Zentrum für Materialforschung, Justus-Liebig-Universität Giessen, Heinrich-Buff-Ring 17, D-35392 Giessen, Germany
| | | | - Michael Dürr
- Institut für Angewandte Physik and Zentrum für Materialforschung, Justus-Liebig-Universität Giessen, Heinrich-Buff-Ring 16, 35392 Giessen, Germany.
| |
Collapse
|
3
|
Bomhardt K, Schneider P, Portz A, Gebhardt CR, Dürr M. Analysis of Complex Molecules and Their Reactions on Surfaces by Means of Cluster-Induced Desorption/Ionization Mass Spectrometry. J Vis Exp 2020. [PMID: 32176198 DOI: 10.3791/60487] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Desorption/Ionization Induced by Neutral SO2 Clusters (DINeC) is employed as a very soft and efficient desorption/ionization technique for mass spectrometry (MS) of complex molecules and their reactions on surfaces. DINeC is based on a beam of SO2 clusters impacting on the sample surface at low cluster energy. During cluster-surface impact, some of the surface molecules are desorbed and ionized via dissolvation in the impacting cluster; as a result of this dissolvation-mediated desorption mechanism, low cluster energy is sufficient and the desorption process is extremely soft. Both surface adsorbates and molecules of which the surface is composed of can be analyzed. Clear and fragmentation-free spectra from complex molecules such as peptides and proteins are obtained. DINeC does not require any special sample preparation, in particular no matrix has to be applied. The method yields quantitative information on the composition of the samples; molecules at a surface coverage as low as 0.1 % of a monolayer can be detected. Surface reactions such as H/D exchange or thermal decomposition can be observed in real-time and the kinetics of the reactions can be deduced. Using a pulsed nozzle for cluster beam generation, DINeC can be efficiently combined with ion trap mass spectrometry. The matrix-free and soft nature of the DINeC process in combination with the MSn capabilities of the ion trap allows for very detailed and unambiguous analysis of the chemical composition of complex organic samples and organic adsorbates on surfaces.
Collapse
Affiliation(s)
- Karolin Bomhardt
- Institute of Applied Physics and Center for Materials Research (LaMa), Justus Liebig University Giessen
| | - Pascal Schneider
- Institute of Applied Physics and Center for Materials Research (LaMa), Justus Liebig University Giessen
| | - André Portz
- Institute of Applied Physics and Center for Materials Research (LaMa), Justus Liebig University Giessen
| | | | - Michael Dürr
- Institute of Applied Physics and Center for Materials Research (LaMa), Justus Liebig University Giessen;
| |
Collapse
|
4
|
Heep J, Tuchecker PHK, Gebhardt CR, Dürr M. Combination of Thin-Layer Chromatography and Mass Spectrometry Using Cluster-Induced Desorption/Ionization. ACS Omega 2019; 4:22426-22430. [PMID: 31909324 PMCID: PMC6941192 DOI: 10.1021/acsomega.9b03060] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 11/26/2019] [Indexed: 06/10/2023]
Abstract
Desorption/ionization induced by neutral clusters (DINeC) was employed for mass spectrometry (MS) of oligopeptides and lipids after separation by means of thin-layer chromatography (TLC). Clear and fragmentation-free spectra were obtained from the TLC plates without any further sample treatment. Mass-resolved chromatograms were deduced when scanning the TLC plates with the cluster beam along the direction of solvent movement. Using vancomycin and noncovalently bound complexes, the soft nature of DINeC was demonstrated also when used in combination with TLC. As a test application, TLC and DINeC-MS were employed to separate and detect different phospholipids obtained from egg yolk.
Collapse
Affiliation(s)
- Julian Heep
- Institut
für Angewandte Physik and Zentrum für Materialforschung, Justus-Liebig-Universität Giessen, Heinrich-Buff-Ring 16, D-35392 Giessen, Germany
| | - Paul H. K. Tuchecker
- Institut
für Angewandte Physik and Zentrum für Materialforschung, Justus-Liebig-Universität Giessen, Heinrich-Buff-Ring 16, D-35392 Giessen, Germany
| | | | - Michael Dürr
- Institut
für Angewandte Physik and Zentrum für Materialforschung, Justus-Liebig-Universität Giessen, Heinrich-Buff-Ring 16, D-35392 Giessen, Germany
| |
Collapse
|
5
|
Portz A, Gebhardt CR, Dürr M. Real-Time Investigation of the H/D Exchange Kinetics of Porphyrins and Oligopeptides by Means of Neutral Cluster-Induced Desorption/Ionization Mass Spectrometry. J Phys Chem B 2017; 121:11031-11036. [PMID: 29160071 DOI: 10.1021/acs.jpcb.7b06897] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The kinetics of the H/D exchange reaction in angiotensin II, hexaglycine (Gly6), Co(II)tetra(3-carboxyphenyl)porphyrin, and tetra(4-carboxyphenyl)porphyrin were followed in real time by mass spectrometry employing desorption/ionization induced by neutral SO2 clusters. The change of the isotope patterns with increasing degree of deuteration was recorded as a function of D2O exposure and the underlying H/D exchange kinetics, i.e., the dependence of the different degrees of deuteration on time, were deduced. The results were modeled by means of Monte Carlo simulations taking into account different reaction constants for the H/D exchange reaction at different functional groups. In the case of the investigated porphyrins, the rate constants were directly assigned to the functional groups involved; in the case of the peptides, reaction at the explicit functional groups and the backbone chain of the molecules could be discriminated.
Collapse
Affiliation(s)
- André Portz
- Institut für Angewandte Physik, Justus-Liebig-Universität Giessen , Heinrich-Buff-Ring 16, D-35392 Giessen, Germany
| | | | - Michael Dürr
- Institut für Angewandte Physik, Justus-Liebig-Universität Giessen , Heinrich-Buff-Ring 16, D-35392 Giessen, Germany
| |
Collapse
|
6
|
Portz A, Baur M, Gebhardt CR, Frank AJ, Neuderth P, Eickhoff M, Dürr M. Influence of the cluster constituents' reactivity on the desorption/ionization process induced by neutral SO 2 clusters. J Chem Phys 2017; 146:134705. [PMID: 28390387 DOI: 10.1063/1.4979488] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The influence of the chemical nature of the cluster constituents on the desorption/ionization process was investigated for desorption/ionization induced by neutral SO2 clusters (DINeC). The polar clusters act as a transient matrix in which the desorbed analyte molecules are dissolved during the desorption process. For drop-cast samples, the desorption/ionization efficiency was found to be largely independent of the pH value of the initial solution the samples were prepared from; positive ions were almost always dominant and no multiply charged negative ions were observed. The results were traced back to the interaction of SO2 with water present in the samples. Both H/D exchange experiments and surface charge measurements showed that SO2 from the cluster beam interacts with water on and in the sample forming sulfurous acid. The latter then acts as an efficient proton supply leading to an enhanced ionization efficiency. The results demonstrate the possibility to control the ionization efficiency when using reactive cluster constituents in desorption-based ionization methods such as DINeC and cluster-based secondary ion mass spectrometry.
Collapse
Affiliation(s)
- A Portz
- Institut für Angewandte Physik, Justus-Liebig-Universität Giessen, Heinrich-Buff-Ring 16, D-35392 Giessen, Germany
| | - M Baur
- Institut für Angewandte Physik, Justus-Liebig-Universität Giessen, Heinrich-Buff-Ring 16, D-35392 Giessen, Germany
| | - C R Gebhardt
- Bruker Daltonik GmbH, Fahrenheitstr. 4, D-28359 Bremen, Germany
| | - A J Frank
- I. Physikalisches Institut, Justus-Liebig-Universität Giessen, Heinrich-Buff-Ring 16, D-35392 Giessen, Germany
| | - P Neuderth
- I. Physikalisches Institut, Justus-Liebig-Universität Giessen, Heinrich-Buff-Ring 16, D-35392 Giessen, Germany
| | - M Eickhoff
- I. Physikalisches Institut, Justus-Liebig-Universität Giessen, Heinrich-Buff-Ring 16, D-35392 Giessen, Germany
| | - M Dürr
- Institut für Angewandte Physik, Justus-Liebig-Universität Giessen, Heinrich-Buff-Ring 16, D-35392 Giessen, Germany
| |
Collapse
|
7
|
Martens J, Berden G, Gebhardt CR, Oomens J. Infrared ion spectroscopy in a modified quadrupole ion trap mass spectrometer at the FELIX free electron laser laboratory. Rev Sci Instrum 2016; 87:103108. [PMID: 27802712 DOI: 10.1063/1.4964703] [Citation(s) in RCA: 124] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We report on modifications made to a Paul-type quadrupole ion trap mass spectrometer and discuss its application in infrared ion spectroscopy experiments. Main modifications involve optical access to the trapped ions and hardware and software coupling to a variety of infrared laser sources at the FELIX infrared free electron laser laboratory. In comparison to previously described infrared ion spectroscopy experiments at the FELIX laboratory, we find significant improvements in efficiency and sensitivity. Effects of the trapping conditions of the ions on the IR multiple photon dissociation spectra are explored. Enhanced photo-dissociation is found at lower pressures in the ion trap. Spectra obtained under reduced pressure conditions are found to more closely mimic those obtained in the high-vacuum conditions of an Fourier transform ion cyclotron resonance mass spectrometer. A gas-mixing system is described enabling the controlled addition of a secondary gas into helium buffer gas flowing into the trap and allows for ion/molecule reactions in the trap. The electron transfer dissociation (ETD) option of the mass spectrometer allows for IR structure characterization of ETD-generated peptide dissociation products.
Collapse
Affiliation(s)
- Jonathan Martens
- Radboud University, Institute for Molecules and Materials, FELIX Laboratory, Toernooiveld 7c, 6525ED Nijmegen, The Netherlands
| | - Giel Berden
- Radboud University, Institute for Molecules and Materials, FELIX Laboratory, Toernooiveld 7c, 6525ED Nijmegen, The Netherlands
| | | | - Jos Oomens
- Radboud University, Institute for Molecules and Materials, FELIX Laboratory, Toernooiveld 7c, 6525ED Nijmegen, The Netherlands
| |
Collapse
|
8
|
Baur M, Gebhardt CR, Dürr M. Desorption/ionization induced by neutral cluster impact as a soft and efficient ionization source for ion trap mass spectrometry of biomolecules. Rapid Commun Mass Spectrom 2014; 28:290-296. [PMID: 24375880 DOI: 10.1002/rcm.6781] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Revised: 10/31/2013] [Accepted: 10/31/2013] [Indexed: 06/03/2023]
Abstract
RATIONALE Desorption and ionization induced by neutral clusters (DINeC) using SO2 as cluster constituents was previously shown to produce clear and fragmentation-free spectra with low background from samples prepared with standard oligopeptides. Here we demonstrate a more general applicability of this method based on examples from different classes of (bio-)molecules. In order to make better use of the ions generated during the millisecond cluster-pulse, the DINeC source was combined with an ion trap mass spectrometer. METHODS Desorption and ionization was induced by neutral SO2 clusters with a mean size of 10(3) to 10(4) molecules seeded in a pulsed He beam. The desorbed ions were accumulated in an ion trap over the whole pulse duration prior to mass spectrometric analysis. Samples were prepared by simply drop casting the respective aqueous solution of biomolecules on Si/SiO2 substrates. RESULTS Clear and fragmentation-free spectra of oligopeptides were detected in single pulse operation mode. The very soft nature of the desorption process was demonstrated for phosphopeptides. DINeC spectra from bovine serum albumin samples after tryptic digest led to a clear identification of the original sequence using mass fingerprinting analysis. MS(n) capability was illustrated with two types of rhodamine dyes. CONCLUSIONS Desorption and ionization induced by neutral clusters can efficiently be combined with ion trap mass spectrometry since the pulse width and repetition rate of a typical pulsed cluster beam correspond well to the discontinuous accumulation time as well as the spectral rate of the ion trap. Clear mass spectra were obtained with such a setup for a variety of biosamples demonstrating the wider applicability of the DINeC process.
Collapse
Affiliation(s)
- Markus Baur
- Fakultät Angewandte Naturwissenschaften, Hochschule Esslingen, Kanalstr. 33, D-73728, Esslingen, Germany
| | | | | |
Collapse
|
9
|
Lee BJ, Baur M, Gebhardt CR, Dürr M. Quantification of the ionization probability during desorption/ionization of oligopeptides induced by neutral cluster impact. Rapid Commun Mass Spectrom 2013; 27:1090-1094. [PMID: 23592213 DOI: 10.1002/rcm.6550] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Revised: 01/18/2013] [Accepted: 02/17/2013] [Indexed: 06/02/2023]
Abstract
RATIONALE Desorption-and-ionization induced by neutral cluster impact is a soft and matrix-free method, which leads to the formation of free ions of oligopeptides and smaller proteins without fragmentation. As a prerequisite for its successful application in bioanalytics, especially with respect to sensitivity, the ionization efficiency, i.e., the ion-to-neutral ratio of the desorbing molecules, was determined. METHODS Neutral SO2 clusters of 10(3) to 10(4) molecules in size were seeded in a pulsed He beam and used to desorb and ionize oligopeptides by means of cluster surface impact. The samples were prepared by drop casting a well-defined amount of substance on the substrate surface; the desorbing ions were identified by means of time-of-flight mass spectrometry. Furthermore, the ion current leaving the surface was determined for positive ions, which predominate in the investigated oligopeptides. RESULTS For angiotensin II, bradykinin (1-7), and adrenocorticotropic hormone (34-39), the number of ions desorbed from the respective samples was compared with the amount of substance applied on the substrate. Assuming that all biomolecules were desorbed during the experiment, the ion-to-neutral ratio or ionization efficiency η was determined. For the tested molecules, values of η between 0.5% and 3% were observed; the substrate material and the total amount of substance applied were shown to have a minor effect on the results. CONCLUSIONS The ion-to-neutral ratio in desorption/ionization of oligopeptides induced by neutral cluster impact was determined to be of the order of 10(-3) to 10(-2). The soft and matrix-free nature of the method in combination with this value of η might be interesting for applications in bioanalytics.
Collapse
Affiliation(s)
- B-J Lee
- Fakultät Angewandte Naturwissenschaften, Hochschule Esslingen, Esslingen, Germany
| | | | | | | |
Collapse
|
10
|
Tomsic A, Gebhardt CR. A comparative study of cluster-surface collisions: Molecular-dynamics simulations of (H2O)1000 and (SO2)1000. J Chem Phys 2007; 123:64704. [PMID: 16122332 DOI: 10.1063/1.1997109] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
A classical molecular-dynamics study of (H2O)1000 and (SO2)1000 clusters impacting with velocities between 6 x 10(2) and 8 x 10(3) ms at normal incidence on a repulsive target is presented. Using the ratio of total kinetic energy to total binding energy of the cluster as a scaling parameter, a general description of the fragmentation dynamics as well as the final fragment size distributions is achieved for the different systems. With increasing ratio, the angular distribution of the emitted monomers rapidly shifts from isotropic to anisotropic. At the highest investigated velocities, a tendency to recover more isotropic distributions is observed. Comparable transient compression of the impacting cluster is reached, on the other hand, for the same, unscaled collision velocities in both systems. For both H2O and SO2 the obtained internal temperatures of the cluster fragments are found to be independent of impact energy and close to the boiling temperature of the respective systems.
Collapse
Affiliation(s)
- A Tomsic
- Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, D-85748 Garching, Germany.
| | | |
Collapse
|
11
|
Gebhardt CR, Witte T, Kompa KL. Cover Picture: Direct Observation of Charge-Transfer Reactions in Nanoscopic Test Tubes: Self-Ionization in HNO3 Clusters (ChemPhysChem 3/2003). Chemphyschem 2003. [DOI: 10.1002/cphc.200390037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
12
|
Gebhardt CR, Witte T, Kompa KL. Direct observation of charge-transfer reactions in nanoscopic test tubes: self-ionization in HNO3 clusters. Chemphyschem 2003; 4:308-12. [PMID: 12674608 DOI: 10.1002/cphc.200390052] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Christoph R Gebhardt
- Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching, Germany
| | | | | |
Collapse
|
13
|
|