Metabolic profiling by ion mobility mass spectrometry (IMMS)
Ion Mobility Mass Spectrometry (IMMS) was evaluated as an analytical method for metabolic profiling. The specific instrument used in these studies was a direct infusion (DI)-electrospray ionization (ESI)—ambient pressure ion mobility spectrometer (APIMS) coupled to a time-of-flight mass spectrometer (TOFMS). The addition of an ion mobility spectrometer to a mass spectrometer had several advantages over direct infusion electrospray mass spectrometry alone. This tandem instrument (ESI-IMMS) added a rapid separation step with high-resolution prior to mass spectrometric analysis of metabolite mixtures without extending sample preparation time or reducing the high through put potential of direct mass spectrometry. Further, IMMS also reduced the baseline noise common with ESI-MS analyses of complex samples and enabled rapid separation of isobaric metabolites. IMMS was used to analyze the metabolome of Escherichiacoli (E. coli), containing a collection of extremely diverse chemical compounds including hydrophobic lipids, inorganic ions, volatile alcohols and ketones, amino and non-amino organic acids, and hydrophilic carbohydrates. IMMS data were collected as two-dimensional spectra showing both mobility and mass of each ion detected. Using direct infusion ESI-IMMS of a non-derivatized methanol extract of an E. coli culture, more than 500 features were detected, of which over 200 intracellular metabolites were tentatively assigned as E. coli metabolites. This analytical method also allowed simultaneous separation of isomeric metabolic features.
KeywordsIon mobility spectrometry Metabolomics Mass spectrometry E coli metabolome Electrospray ionization
- Duarte, N. C., Becker, S. A., Jamshidi, N., Thiele, I., Mo, M. L., Vo, T. D., Srivas, R., & Palsson, B. O. (2007). Global reconstruction of the human metabolic network based on genomic and bibliomic data. Proceedings of the National Academy of Sciences of the United States of America, 104, 1777–1782.PubMedCrossRefGoogle Scholar
- Dwivedi, P., Bendiak, B. A., Clowers, B. H., & Hill, H. H. (2007). Rapid resolution of carbohydrate isomers by electrospray ionization ambient pressure ion mobility spectrometry-time-of-flight mass spectrometry (ESI-APIMS-TOFMS). Journal of the American Society for Mass Spectrometry, 18(7), 1163–1175.PubMedCrossRefGoogle Scholar
- Harrigan, G. G., LaPlante, R. H., Cosma, G. N., Cockerell, G., Goodacre, R., Maddox, J. F., Luyendyk, J. P., Ganey, P. E., & Roth, R. A. (2004). Application of high-throughput Fourier-transform infrared spectroscopy in toxicology studies: Contribution to a study on the development of an animal model for idiosyncratic toxicity. Toxicology Letters, 146, 197–205.PubMedCrossRefGoogle Scholar
- Johnson, H. E., Broadhurst, D., Kell, D. B., Theodorou, M. K., Merry, R. J., & Griffith, G. W. (2004). High-throughput metabolic fingerprinting of legume silage fermentations via Fourier transform infrared spectroscopy and chemometrics. Applied and Environmental Microbiology, 70, 1583–1592.PubMedCrossRefGoogle Scholar
- Steiner, W. E., Clowers, B. H., Fuhrer, K., Gonin, M., Matz, L. M., Siems, W. F., Schultz, A. J., & Hill, H. H. (2001). Electrospray ionization with ambient pressure ion mobility separation and mass analysis by orthogonal time-of-flight mass spectrometry. Rapid Communications in Mass Spectrometry, 15, 2221–2226.PubMedCrossRefGoogle Scholar