HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY CONTINUOUS-FLOW LIQUID SECONDARY-ION MASS-SPECTROMETRY OF FLAVONOID GLYCOSIDES IN LEGUMINOUS PLANT-EXTRACTS

A method for the identification of flavonoid glycosides utilizing cont inuous-flow liquid secondary ion mass spectrometry (CF-LSIMS) is prese nted. Minimum detectable quantities (MDQs) were determined for three m odel flavonoid glycosides (rutin, naringin and esculin) by both positi ve ion direct insertion probe (DIP)-LSIMS (1.6 nmol, 1.7 nmol and 730 pmol, respectively) and positive ion CF-LSIMS (330 pmol, 340 pmol and 290 pmol, respectively). Optimization of CF-LSIMS instrumental paramet ers was performed using the model compound rutin. Parameters optimized included mobile phase composition, glycerol concentration, mobile pha se dow rate, ion source temperature, acceleration lens potential (ampl itude and polarity) and Cs+ primary ion energy. Final instrumental opt imization yielded an MDQ of 1.0 ng (1.6 pmol) for rutin by flow-inject ion CF-LSIMS. The optimization parameters were utilized in the identif ication of flavonoid glucosides in alfalfa (Medicago sativa L) and chi ckpea (Cicer arietinum) extracts by high-performance liquid chromatogr aphy/CF-LSIMS. The results support the controversial identification of a major extract component as formonentin-7-O-glucoside-6 ''-malonate as opposed to afrormosin-7-O-glucoside-6 ''-malonate.