IDENTIFICATION OF INTACT GLUCOSINOLATES USING DIRECT COUPLING OF HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY WITH CONTINUOUS-FLOW FRIT FAST-ATOM-BOMBARDMENT TANDEM MASS-SPECTROMETRY

Intact glucosinolates have been separated and identified in standard mixtures using liquid chromatography (LC) and continuous-flow frit fast atom bombardment tandem mass spectrometry. The separation of individual glucosinolates is achieved by using a conventional-bore LC column with an aqueous ammonium acetate-acetonitrile gradient. The mandatory flow rate reduction is achieved by using a pneumatic splitter. The daughter ion spectra after collision-induced dissociation of the characteristic [M - H]- anion glucosinates yields extensive structure information. Both group- and compound-specific fragments and group-characteristic neutral losses are observed. Strategies for identification of unknown glucosinolates in a mixture from their negative ion tandem mass spectra are indicated.