PRECOLUMN DERIVATIZATION AND CAPILLARY LIQUID CHROMATOGRAPHIC FRIT-FAST ATOM BOMBARDMENT MASS-SPECTROMETRIC ANALYSIS OF CYTOKININS IN ARABIDOPSIS-THALIANA/

New cytokinin derivatives with high surface activity were developed fo r capillary liquid chromatography/frit-fast atom bombardment (FAB) mas s spectrometry. Propionyl ester derivatives of cytokinin nucleosides a nd glucosides and benzylamine derivatives of cytokinin bases gave stro nger [M + H](+) ion currents than the underivatized compounds. In trac e analysis by selective reaction monitoring, low (fmole) detection lim its were found. In qualitative analysis by BIE-linked scanning, the de rivatives also gave more spectral information, owing to the presence o f fragment ions, diagnostic for the sugar moieties of nucleosides and glucosides, not present in the spectra of underivatized compounds. The proposed FAB method was used to identify and quantify 10 isoprenoid c ytokinins in Arabidopsis thaliana, including free bases, nucleosides, nucleotides and glucosides. (C) 1998 John Wiley & Sons, Ltd.