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Rudolf-Scholik J, Lilek D, Maier M, Reischenböck T, Maisl C, Allram J, Herbinger B, Rechthaler J. Increasing protein identifications in bottom-up proteomics of T. castaneum - Exploiting synergies of protein biochemistry and bioinformatics. J Chromatogr B Analyt Technol Biomed Life Sci 2024; 1240:124128. [PMID: 38759531 DOI: 10.1016/j.jchromb.2024.124128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 03/29/2024] [Accepted: 04/14/2024] [Indexed: 05/19/2024]
Abstract
Depending on the respective research question, LC-MS/MS based bottom-up proteomics poses challenges from the initial biological sample all the way to data evaluation. The focus of this study was to investigate the influence of sample preparation techniques and data analysis parameters on protein identification in Tribolium castaneum by applying free software proteomics platform Max Quant. Multidimensional protein extraction strategies in combination with electrophoretic or chromatographic off-line protein pre-fractionation were applied to enhance the spectrum of isolated proteins from T. castaneum and reduce the effect of co-elution and ion suppression effects during nano-LC-MS/MS measurements of peptides. For comprehensive data analysis, MaxQuant was used for protein identification and R for data evaluation. A wide range of parameters were evaluated to gain reproducible, reliable, and significant protein identifications. A simple phosphate buffer, pH 8, containing protease and phosphatase inhibitor cocktail and application of gentle extraction conditions were used as a first extraction step for T.castaneum proteins. Furthermore, a two-dimensional extraction procedure in combination with electrophoretic pre-fractionation of extracted proteins and subsequent in-gel digest resulted in almost 100% increase of identified proteins when compared to chromatographic fractionation as well as one-pot-analysis. The additionally identified proteins could be assigned to new molecular functions or cell compartments, emphasizing the positive effect of extended sample preparation in bottom-up proteomics. Besides the number of peptides during post-processing, MaxQuant's Match between Runs exhibited a crucial effect on the number of identified proteins. A maximum relative standard deviation of 2% must be considered for the data analysis. Our work with Tribolium castaneum larvae demonstrates that sometimes - depending on matrix and research question - more complex and time-consuming sample preparation can be advantageous for isolation and identification of additional proteins in bottom-up proteomics.
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Affiliation(s)
- J Rudolf-Scholik
- University of Applied Sciences Wiener Neustadt, Biotech Campus Tulln, AUSTRIA.
| | - D Lilek
- University of Applied Sciences Wiener Neustadt, Biotech Campus Tulln, AUSTRIA
| | - M Maier
- University of Applied Sciences Wiener Neustadt, Biotech Campus Tulln, AUSTRIA
| | - T Reischenböck
- University of Applied Sciences Wiener Neustadt, Biotech Campus Tulln, AUSTRIA
| | - C Maisl
- University of Applied Sciences Wiener Neustadt, Biotech Campus Tulln, AUSTRIA
| | - J Allram
- University of Applied Sciences Wiener Neustadt, Biotech Campus Tulln, AUSTRIA
| | - B Herbinger
- University of Applied Sciences Wiener Neustadt, Biotech Campus Tulln, AUSTRIA
| | - J Rechthaler
- University of Applied Sciences Wiener Neustadt, Biotech Campus Tulln, AUSTRIA
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Doppler M, Bueschl C, Kluger B, Koutnik A, Lemmens M, Buerstmayr H, Rechthaler J, Krska R, Adam G, Schuhmacher R. Stable Isotope-Assisted Plant Metabolomics: Combination of Global and Tracer-Based Labeling for Enhanced Untargeted Profiling and Compound Annotation. Front Plant Sci 2019; 10:1366. [PMID: 31708958 PMCID: PMC6824187 DOI: 10.3389/fpls.2019.01366] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 10/04/2019] [Indexed: 05/10/2023]
Abstract
Untargeted approaches and thus biological interpretation of metabolomics results are still hampered by the reliable assignment of the global metabolome as well as classification and (putative) identification of metabolites. In this work we present an liquid chromatography-mass spectrometry (LC-MS)-based stable isotope assisted approach that combines global metabolome and tracer based isotope labeling for improved characterization of (unknown) metabolites and their classification into tracer derived submetabolomes. To this end, wheat plants were cultivated in a customized growth chamber, which was kept at 400 ± 50 ppm 13CO2 to produce highly enriched uniformly 13C-labeled sample material. Additionally, native plants were grown in the greenhouse and treated with either 13C9-labeled phenylalanine (Phe) or 13C11-labeled tryptophan (Trp) to study their metabolism and biochemical pathways. After sample preparation, liquid chromatography-high resolution mass spectrometry (LC-HRMS) analysis and automated data evaluation, the results of the global metabolome- and tracer-labeling approaches were combined. A total of 1,729 plant metabolites were detected out of which 122 respective 58 metabolites account for the Phe- and Trp-derived submetabolomes. Besides m/z and retention time, also the total number of carbon atoms as well as those of the incorporated tracer moieties were obtained for the detected metabolite ions. With this information at hand characterization of unknown compounds was improved as the additional knowledge from the tracer approaches considerably reduced the number of plausible sum formulas and structures of the detected metabolites. Finally, the number of putative structure formulas was further reduced by isotope-assisted annotation tandem mass spectrometry (MS/MS) derived product ion spectra of the detected metabolites. A major innovation of this paper is the classification of the metabolites into submetabolomes which turned out to be valuable information for effective filtering of database hits based on characteristic structural subparts. This allows the generation of a final list of true plant metabolites, which can be characterized at different levels of specificity.
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Affiliation(s)
- Maria Doppler
- Department of Agrobiotechnology (IFA-Tulln), Institute of Bioanalytics and Agro-Metabolomics, University of Natural Resources and Life Sciences, Vienna (BOKU), Tulln, Austria
| | - Christoph Bueschl
- Department of Agrobiotechnology (IFA-Tulln), Institute of Bioanalytics and Agro-Metabolomics, University of Natural Resources and Life Sciences, Vienna (BOKU), Tulln, Austria
| | - Bernhard Kluger
- Department of Agrobiotechnology (IFA-Tulln), Institute of Bioanalytics and Agro-Metabolomics, University of Natural Resources and Life Sciences, Vienna (BOKU), Tulln, Austria
| | - Andrea Koutnik
- Department of Agrobiotechnology (IFA-Tulln), Institute of Bioanalytics and Agro-Metabolomics, University of Natural Resources and Life Sciences, Vienna (BOKU), Tulln, Austria
| | - Marc Lemmens
- Department of Agrobiotechnology (IFA-Tulln), Institute for Biotechnology in Plant Production, University of Natural Resources and Life Sciences, Vienna (BOKU), Tulln, Austria
| | - Hermann Buerstmayr
- Department of Agrobiotechnology (IFA-Tulln), Institute for Biotechnology in Plant Production, University of Natural Resources and Life Sciences, Vienna (BOKU), Tulln, Austria
| | - Justyna Rechthaler
- University of Applied Sciences Wr. Neustadt, Degree Programme Biotechnical Processes (FHWN-Tulln), Tulln, Austria
| | - Rudolf Krska
- Department of Agrobiotechnology (IFA-Tulln), Institute of Bioanalytics and Agro-Metabolomics, University of Natural Resources and Life Sciences, Vienna (BOKU), Tulln, Austria
- School of Biological Sciences, Institute for Global Food Security, Queen's University Belfast, Belfast, United Kingdom
| | - Gerhard Adam
- Department of Applied Genetics and Cell Biology (DAGZ), University of Natural Resources and Life Sciences, Vienna (BOKU), Tulln, Austria
| | - Rainer Schuhmacher
- Department of Agrobiotechnology (IFA-Tulln), Institute of Bioanalytics and Agro-Metabolomics, University of Natural Resources and Life Sciences, Vienna (BOKU), Tulln, Austria
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3
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Meng-Reiterer J, Varga E, Nathanail AV, Bueschl C, Rechthaler J, McCormick SP, Michlmayr H, Malachová A, Fruhmann P, Adam G, Berthiller F, Lemmens M, Schuhmacher R. Tracing the metabolism of HT-2 toxin and T-2 toxin in barley by isotope-assisted untargeted screening and quantitative LC-HRMS analysis. Anal Bioanal Chem 2015; 407:8019-33. [PMID: 26335000 PMCID: PMC4595538 DOI: 10.1007/s00216-015-8975-9] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 08/10/2015] [Accepted: 08/12/2015] [Indexed: 12/02/2022]
Abstract
An extensive study of the metabolism of the type A trichothecene mycotoxins HT-2 toxin and T-2 toxin in barley using liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS) is reported. A recently developed untargeted approach based on stable isotopic labelling, LC-Orbitrap-MS analysis with fast polarity switching and data processing by MetExtract software was combined with targeted LC-Q-TOF-MS(/MS) analysis for metabolite structure elucidation and quantification. In total, 9 HT-2 toxin and 13 T-2 toxin metabolites plus tentative isomers were detected, which were successfully annotated by calculation of elemental formulas and further LC-HRMS/MS measurements as well as partly identified with authentic standards. As a result, glucosylated forms of the toxins, malonylglucosides, and acetyl and feruloyl conjugates were elucidated. Additionally, time courses of metabolite formation and mass balances were established. For absolute quantification of those compounds for which standards were available, the method was validated by determining apparent recovery, signal suppression, or enhancement and extraction recovery. Most importantly, T-2 toxin was rapidly metabolised to HT-2 toxin and for both parent toxins HT-2 toxin-3-O-β-glucoside was identified (confirmed by authentic standard) as the main metabolite, which reached its maximum already 1 day after toxin treatment. Graphical Abstract Isotope-assisted untargeted screening of HT-2 toxin and T-2 toxin metabolites in barley.
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Affiliation(s)
- Jacqueline Meng-Reiterer
- Center for Analytical Chemistry, Department of Agrobiotechnology (IFA-Tulln), University of Natural Resources and Life Sciences, Vienna (BOKU), Konrad-Lorenz-Str. 20, 3430, Tulln, Austria
- Institute for Biotechnology in Plant Production, IFA-Tulln, BOKU, Konrad-Lorenz-Str. 20, 3430, Tulln, Austria
| | - Elisabeth Varga
- Center for Analytical Chemistry, Department of Agrobiotechnology (IFA-Tulln), University of Natural Resources and Life Sciences, Vienna (BOKU), Konrad-Lorenz-Str. 20, 3430, Tulln, Austria
- Christian Doppler Laboratory for Mycotoxin Metabolism, IFA-Tulln, BOKU, Konrad-Lorenz-Str. 20, 3430, Tulln, Austria
| | - Alexis V Nathanail
- Chemistry and Toxicology Unit, Research and Laboratory Department, Finnish Food Safety Authority (Evira), Mustialankatu 3, 00790, Helsinki, Finland
| | - Christoph Bueschl
- Center for Analytical Chemistry, Department of Agrobiotechnology (IFA-Tulln), University of Natural Resources and Life Sciences, Vienna (BOKU), Konrad-Lorenz-Str. 20, 3430, Tulln, Austria
| | - Justyna Rechthaler
- University of Applied Sciences Wr. Neustadt, Degree Programme Biotechnical Processes (FHWN-Tulln), Konrad-Lorenz-Str. 10, 3430, Tulln, Austria
| | - Susan P McCormick
- Bacterial Foodborne Pathogens and Mycology Research Unit, National Center for Agricultural Utilization Research, U.S. Department of Agriculture, 1815 N. University Street, Peoria, IL, 61604, USA
| | - Herbert Michlmayr
- Department of Applied Genetics and Cell Biology, BOKU, Konrad-Lorenz-Str. 24, 3430, Tulln, Austria
| | - Alexandra Malachová
- Center for Analytical Chemistry, Department of Agrobiotechnology (IFA-Tulln), University of Natural Resources and Life Sciences, Vienna (BOKU), Konrad-Lorenz-Str. 20, 3430, Tulln, Austria
- Christian Doppler Laboratory for Mycotoxin Metabolism, IFA-Tulln, BOKU, Konrad-Lorenz-Str. 20, 3430, Tulln, Austria
| | - Philipp Fruhmann
- Department of Applied Genetics and Cell Biology, BOKU, Konrad-Lorenz-Str. 24, 3430, Tulln, Austria
- Institute of Applied Synthetic Chemistry, Vienna University of Technology, Getreidemarkt 9/163, 1060, Vienna, Austria
| | - Gerhard Adam
- Department of Applied Genetics and Cell Biology, BOKU, Konrad-Lorenz-Str. 24, 3430, Tulln, Austria
| | - Franz Berthiller
- Center for Analytical Chemistry, Department of Agrobiotechnology (IFA-Tulln), University of Natural Resources and Life Sciences, Vienna (BOKU), Konrad-Lorenz-Str. 20, 3430, Tulln, Austria
- Christian Doppler Laboratory for Mycotoxin Metabolism, IFA-Tulln, BOKU, Konrad-Lorenz-Str. 20, 3430, Tulln, Austria
| | - Marc Lemmens
- Institute for Biotechnology in Plant Production, IFA-Tulln, BOKU, Konrad-Lorenz-Str. 20, 3430, Tulln, Austria
| | - Rainer Schuhmacher
- Center for Analytical Chemistry, Department of Agrobiotechnology (IFA-Tulln), University of Natural Resources and Life Sciences, Vienna (BOKU), Konrad-Lorenz-Str. 20, 3430, Tulln, Austria.
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Kluger B, Bueschl C, Neumann N, Stückler R, Doppler M, Chassy AW, Waterhouse AL, Rechthaler J, Kampleitner N, Thallinger GG, Adam G, Krska R, Schuhmacher R. Untargeted profiling of tracer-derived metabolites using stable isotopic labeling and fast polarity-switching LC-ESI-HRMS. Anal Chem 2014; 86:11533-7. [PMID: 25372979 PMCID: PMC4255957 DOI: 10.1021/ac503290j] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Accepted: 11/05/2014] [Indexed: 02/02/2023]
Abstract
An untargeted metabolomics workflow for the detection of metabolites derived from endogenous or exogenous tracer substances is presented. To this end, a recently developed stable isotope-assisted LC-HRMS-based metabolomics workflow for the global annotation of biological samples has been further developed and extended. For untargeted detection of metabolites arising from labeled tracer substances, isotope pattern recognition has been adjusted to account for nonlabeled moieties conjugated to the native and labeled tracer molecules. Furthermore, the workflow has been extended by (i) an optional ion intensity ratio check, (ii) the automated combination of positive and negative ionization mode mass spectra derived from fast polarity switching, and (iii) metabolic feature annotation. These extensions enable the automated, unbiased, and global detection of tracer-derived metabolites in complex biological samples. The workflow is demonstrated with the metabolism of (13)C9-phenylalanine in wheat cell suspension cultures in the presence of the mycotoxin deoxynivalenol (DON). In total, 341 metabolic features (150 in positive and 191 in negative ionization mode) corresponding to 139 metabolites were detected. The benefit of fast polarity switching was evident, with 32 and 58 of these metabolites having exclusively been detected in the positive and negative modes, respectively. Moreover, for 19 of the remaining 49 phenylalanine-derived metabolites, the assignment of ion species and, thus, molecular weight was possible only by the use of complementary features of the two ion polarity modes. Statistical evaluation showed that treatment with DON increased or decreased the abundances of many detected metabolites.
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Affiliation(s)
- Bernhard Kluger
- Center
for Analytical Chemistry, Department for Agrobiotechnology (IFA-Tulln), University of Natural Resources and Life Sciences
Vienna (BOKU), Konrad-Lorenz-Strasse
20, 3430 Tulln, Austria
| | - Christoph Bueschl
- Center
for Analytical Chemistry, Department for Agrobiotechnology (IFA-Tulln), University of Natural Resources and Life Sciences
Vienna (BOKU), Konrad-Lorenz-Strasse
20, 3430 Tulln, Austria
| | - Nora Neumann
- Center
for Analytical Chemistry, Department for Agrobiotechnology (IFA-Tulln), University of Natural Resources and Life Sciences
Vienna (BOKU), Konrad-Lorenz-Strasse
20, 3430 Tulln, Austria
| | - Romana Stückler
- Department
of Applied Genetics and Cell Biology, University
of Natural Resources and Life Sciences Vienna (BOKU), Konrad-Lorenz-Strasse 24, 3430 Tulln, Austria
| | - Maria Doppler
- Center
for Analytical Chemistry, Department for Agrobiotechnology (IFA-Tulln), University of Natural Resources and Life Sciences
Vienna (BOKU), Konrad-Lorenz-Strasse
20, 3430 Tulln, Austria
| | - Alexander W. Chassy
- Department
of Viticulture and Enology, University of
California Davis, Davis, California 95616, United States
| | - Andrew L. Waterhouse
- Department
of Viticulture and Enology, University of
California Davis, Davis, California 95616, United States
| | - Justyna Rechthaler
- University
of Applied Sciences Wr. Neustadt, Degree Programme Biotechnical Processes
(FHWN-Tulln), Konrad
Lorenz Strasse 10, 3430 Tulln, Austria
| | - Niklas Kampleitner
- University
of Applied Sciences Wr. Neustadt, Degree Programme Biotechnical Processes
(FHWN-Tulln), Konrad
Lorenz Strasse 10, 3430 Tulln, Austria
| | - Gerhard G. Thallinger
- Bioinformatics
Group, Institute for Knowledge Discovery, Graz University of Technology, Petersgasse 14, 8010, Graz, Austria
- BioTechMed OMICS Center
Graz, Stiftingtalstraße 24, 8010, Graz, Austria
| | - Gerhard Adam
- Department
of Applied Genetics and Cell Biology, University
of Natural Resources and Life Sciences Vienna (BOKU), Konrad-Lorenz-Strasse 24, 3430 Tulln, Austria
| | - Rudolf Krska
- Center
for Analytical Chemistry, Department for Agrobiotechnology (IFA-Tulln), University of Natural Resources and Life Sciences
Vienna (BOKU), Konrad-Lorenz-Strasse
20, 3430 Tulln, Austria
| | - Rainer Schuhmacher
- Center
for Analytical Chemistry, Department for Agrobiotechnology (IFA-Tulln), University of Natural Resources and Life Sciences
Vienna (BOKU), Konrad-Lorenz-Strasse
20, 3430 Tulln, Austria
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Rechthaler J, Pittenauer E, Schaub TM, Allmaier G. Detection of amine impurity and quality assessment of the MALDI matrix α-cyano-4-hydroxy-cinnamic acid for peptide analysis in the amol range. J Am Soc Mass Spectrom 2013; 24:701-710. [PMID: 23595260 DOI: 10.1007/s13361-013-0614-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Revised: 02/07/2013] [Accepted: 03/19/2013] [Indexed: 06/02/2023]
Abstract
We have studied sample preparation conditions to increase the reproducibility of positive UV-MALDI-TOF mass spectrometry of peptides in the amol range. By evaluating several α-cyano-4-hydroxy-cinnamic acid (CHCA) matrix batches and preparation protocols, it became apparent that two factors have a large influence on the reproducibility and the quality of the generated peptide mass spectra: (1) the selection of the CHCA matrix, which allows the most sensitive measurements and an easier finding of the "sweet spots," and (2) the amount of the sample volume deposited onto the thin crystalline matrix layer. We have studied in detail the influence of a contaminant, coming from commercial CHCA matrix batches, on sensitivity of generated peptide mass spectra in the amol as well as fmol range of a tryptic peptide mixture. The structure of the contaminant, N,N-dimethylbutyl amine, was determined by applying MALDI-FT-ICR mass spectrometry experiments for elemental composition and MALDI high energy CID experiments utilizing a tandem mass spectrometer (TOF/RTOF). A recrystallization of heavily contaminated CHCA batches that reduces or eliminates the determined impurity is described. Furthermore, a fast and reliable method for the assessment of CHCA matrix batches prior to tryptic peptide MALDI mass spectrometric analyses is presented.
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Affiliation(s)
- Justyna Rechthaler
- Institute of Chemical Technologies and Analytics, Vienna University of Technology, Vienna, Austria
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Rechthaler J, Pelzing M, Ingendoh A, Kukovecz A, Prato M, Kuzmany H, Allmaier G. LDI and ESI MS as well as low energy CID of a self-assembling nanorod-forming fullerene derivative. J Mass Spectrom 2011; 46:1108-1114. [PMID: 22124981 DOI: 10.1002/jms.1996] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
An amphiphatic fullerene derivative (8-(N-Methyl-Fullero-Pyrrolidinium-1-yl-chloride)-3,6-Dioxaoctan-1-Ammonium Chloride (MFPDAC)), which is of great interest in nanotechnology due to the fact that it forms self-assembling fullerenic nanorods, has been structurally characterized with emphasis to its purity and thermal treatment of a formed nanorod film (on a LDI target) by means of laser desorption/ionization (LDI) coupled with high-resolution curved field reflectron time-of-flight (TOF) mass spectrometry, and by low energy MS/MS as well as in-source fragmentation experiments applying an quadrupole ion trap (QIT) combined with a two-stage reflectron TOF analyzer. The interpretation of LDI results has been supplemented by ESI QIT MS(n) (n = 1-3), as well as high-resolution ESI reflectron TOF mass spectrometric experiments. Based on the experimental data obtained by both desorption/ionization techniques, various types of analyzers and sample treatments, we could completely characterize MFPDAC and further found out that the investigated sample was not entirely free of impurities. Furthermore, the envisaged loss of the derivative sidechain upon the heat treatment in vacuum of the self-assembled nanorod sample film on a metallic substrate could be successfully monitored by LDI MS.
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Affiliation(s)
- Justyna Rechthaler
- Institute of Chemical Technologies and Analysis, Vienna University of Technology, Getreidemarkt 9/164, A-1060, Vienna, Austria
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Häubl G, Berthiller F, Hametner C, Rechthaler J, Jaunecker G, Freudenschuss M, Krska R, Schuhmacher R. Characterization of (13C24) T-2 toxin and its use as an internal standard for the quantification of T-2 toxin in cereals with HPLC–MS/MS. Anal Bioanal Chem 2007; 389:931-40. [PMID: 17668191 DOI: 10.1007/s00216-007-1493-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2007] [Revised: 06/29/2007] [Accepted: 07/04/2007] [Indexed: 10/23/2022]
Abstract
In this paper, the structure and the identity of fully 13C-substituted T-2 toxin were confirmed using high-resolution mass spectrometry, 1H-NMR, 13C-NMR, tandem mass spectrometry and HPLC-DAD. The purity of this compound was estimated to be at least 98.8% according to UV data. The isotopic distribution of (13C(24)) T-2 toxin indicated a total isotopic enrichment of 98.2 +/- 1.0 atom% 13C, and the application of different MS measurement modes revealed the MS/MS fragmentation pattern of T-2 toxin. Furthermore, a stable isotope dilution mass spectrometry method for the quantification of T-2 toxin was developed using (13C(24)) T-2 toxin as internal standard. The method was evaluated with and without conventional clean-up and validated for maize and oats. Both cereals showed strong matrix enhancement effects, which could be compensated for through the application of the isotope-substituted internal standard.
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Affiliation(s)
- G Häubl
- Christian Doppler Laboratory for Mycotoxin Research, Department for Agrobiotechnology (IFA-Tulln), University of Natural Resources and Applied Life Sciences, Vienna, Konrad Lorenz Str. 20, 3430 Tulln, Austria
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8
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Häubl G, Berthiller F, Rechthaler J, Jaunecker G, Binder EM, Krska R, Schuhmacher R. Characterization and application of isotope-substituted (13C15)-deoxynivalenol (DON) as an internal standard for the determination of DON. ACTA ACUST UNITED AC 2006; 23:1187-93. [PMID: 17071521 DOI: 10.1080/02652030600654390] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
The powerful combination of liquid chromatography and mass spectrometry (MS) is often limited by matrix effects during ionization in the MS ion source. The use of fully isotope-substituted (13C15)-deoxynivalenol ((13C15)-DON) as an internal standard (IS) corrects matrix effects and improves the accuracy of analytical methods using mass spectrometry for the quantitative determination of the Fusarium mycotoxin deoxynivalenol (DON). The IS was characterized with respect to its chromatographic purity by liquid chromatography-ultraviolet light and its isotope distribution by time-of-flight mass spectrometry. Its low-energy collision-induced dissociation behaviour was compared with DON. Moreover, this work describes the successful application of (13C15)-DON as IS for the determination of DON in maize using high-performance liquid chromatography (HPLC) electrospray (ESI) with tandem mass spectrometry. The results demonstrate that the IS can successfully correct for fluctuations during extraction and clean-up of the sample as well as the ionization of DON in the MS ion source. Random variations in ionization affect the IS in the same way as the analyte. Recoveries for DON in maize of 76% +/- 1.9% (external calibration) or 101% +/- 2.4% (internal calibration) were reached, respectively, after sample clean-up.
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Affiliation(s)
- G Häubl
- Department for Agrobiotechnology (IFA-Tulln), Center for Analytical Chemistry, Christian Doppler Laboratory for Mycotoxin Research, University of Natural Resources and Applied Life Sciences, Konrad Lorenz Str. 20, Vienna, A-3430 Tulln, Austria
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Mannsberger M, Kukovecz A, Georgakilas V, Rechthaler J, Schalko J, Hasi F, Allmaier G, Prato M, Kuzmany H. Thermal stripping of supramolecular structures: C60 nanorods. J Nanosci Nanotechnol 2005; 5:198-203. [PMID: 15853137 DOI: 10.1166/jnn.2005.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
The investigated ionic C60 derivative self-assembles into nanorods. When the functional side groups are removed by heating the nanorods to 623 K, they retain their shape. Utilization of lithographic markers allows the study of identical nanostructures before and after heat treatment by dynamic mode atomic force microscopy. Various independent techniques, including Raman spectroscopy and mass spectroscopy demonstrate that the shape-preserving mechanism is a thermal-stripping process, stabilizing the original supramolecular morphology. The latter implies two coherent sub-processes: detachment of the side groups and oligopolymerization running in parallel, eventually yielding rod-shaped C60 polymers. Synthesizing fullerenic polymers in this way can lead to several applications.
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Affiliation(s)
- Michael Mannsberger
- Institut für Materialphysik, Universität Wien, A-1090 Wien, Strudlhofgasse 4, Austria
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Rechthaler J, Allmaier G. One-way hydrophobic surface foil for UV matrix-assisted laser desorption/ionization mass spectrometry of peptides. Rapid Commun Mass Spectrom 2002; 16:899-902. [PMID: 11948823 DOI: 10.1002/rcm.652] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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