Performance Evaluation of Gas Chromatography鈥揂tmospheric Pressure Chemical Ionization鈥揟ime-of-Flight Mass Spectrometry for Metabolic Fingerprinting and Profiling
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- 作者：Christian J. Wachsmuth ; Martin F. Almstetter ; Magdalena C. Waldhier ; Michael A. Gruber ; Nadine N眉rnberger ; Peter J. Oefner ; Katja Dettmer
- 刊名：Analytical Chemistry
- 出版年：2011
- 出版时间：October 1, 2011
- 年：2011
- 卷：83
- 期：19
- 页码：7514-7522
- 全文大小：814K
- 年卷期：v.83,no.19(October 1, 2011)
- ISSN：1520-6882
文摘
Gas chromatography鈥揳tmospheric-pressure chemical ionization鈥搕ime-of-flight mass spectrometry (GC鈥揂PCI鈥揟OFMS) was compared to GC 脳 GC鈥揺lectron ionization (EI)鈥揟OFMS, GC鈥揈I鈥揟OFMS, GC鈥揷hemical ionization (CI)鈥搎uadrupole mass spectrometry (qMS), and GC鈥揈I鈥搎MS in terms of reproducibility, dynamic range, limit of detection, and quantification using a mix of 43 metabolites and 12 stable isotope-labeled standards. Lower limits of quantification for GC鈥揂PCI鈥揟OFMS ranged between 0.06 and 7.81 渭M, and relative standard deviations for calibration replicates were between 0.4% and 8.7%. For all compounds and techniques, except in four cases, R2 values were above 0.99. Regarding limits of quantification, GC鈥揂PCI鈥揟OFMS was inferior to only GC 脳 GC鈥揈I鈥揟OFMS, but outperformed all other techniques tested. GC鈥揂PCI鈥揟OFMS was further applied to the metabolic fingerprinting of two Escherichia coli strains. Of 45 features that differed significantly (false discovery rate < 0.05) between the strains, 25 metabolites were identified through highly accurate and reproducible (螖m 卤 SD below 5 mDa over m/z 190鈥?22) mass measurements. Starting from the quasimolecular ion, six additional metabolites were identified that had not been found in a previous study using GC 脳 GC鈥揈I鈥揟OFMS and an EI mass spectral library for identification purposes. Silylation adducts formed in the APCI source assisted the identification of unknown compounds, as their formation is structure-dependent and is not observed for compounds lacking a carboxylic group.