17th International Mass Spectrometry Conference :: Prague, 2006
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|Presentation date:||Mon, Aug 28, 2006|
|Presentation time:||14:30 – 16:00|
Moritz Frommberger1, Katrin Wieland2, Matthias Englmann1, Bioern Thiele2, Ulrich Schurr2, Philippe Schmitt-Kopplin11 GSF - National Research Center for Environment and Health, Neuherberg/Munich, Germany
Correspondence address: Moritz Frommberger, GSF - National Research Center for Environment and Health, Institute of Ecological Chemistry, Ingolstaedter Landstrasse 1, Neuherberg/Munich, 85764 Germany.
Keywords: Alkaloids; Mass Spectrometry, Fourier Transform; Metabolic Profiling; MS/MS, Capillary Electrophoresis.
Novel aspect: FTICR/On-Chip Nanospray Mass Spectrometry of Fresh and Aged Tobaccco Leaves, Multiple Cell Analysis by Capillary Electrophoresis/Mass Spectrometry
Two complementary strategies for the analysis of alkaloid metabolites from tobacco tissues in different development stages and from different origin within the plant are presented.
Because of its ultrahigh resolution in excess of 200,000 FWHM in broad band measurements (or up to 1,000,000 FWHM in high resolution mode) and a mass accuracy of routinely less than 0.5 ppm, high field Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) allows for an advanced chemical characterization of metabolites of known and hitherto unknown structure in complex and heterogenous samples of biological origin like plant extracts, natural or artificial oligo- and multispecies systems.
Tobacco leaf extracts show very high complexity in FTICR mass spectrometry with more than 3000 resolved peaks detected in a single analysis. A general strategy for identification of targets in these complex samples from plant origin, starting with metabolite profiling and going downward to single analytes, is presented. Several characteristic metabolites (mainly products of the nicotine metabolism) could be identified in crude methanol extracts.
From target analysis upward, capillary electrophoresis with UV detection and capillary electrophoresis coupled to electrospray ionization-mass spectrometry (CE/MS) has been used for the analysis of alkaloids in single cell samples obtained from different leaf tissues of tobacco plants and from single trichoma of the leaf surface. Complementary results from ultra-pressure liquid chromatography (UPLCTM) are also presented.
An electrolyte consisting of ammonium acetate and 10 % v/v 2-propanol adjusted to pH 3.6 was found to yield best separation efficiency in CE/MS. Samples from the epidermis, from mesophyll and from trichomes of tobacco leaves were pooled and extracted. 13 different alkaloids could be distinguished by CE-MS analysis
The results indicate differences in the alkaloid composition in different leaf tissues and confirm previous results on pooled cells from plants under different fertilization regimes as measured by capillary electrophoresis with UV detection.