APPLICATION OF LIQUID-CHROMATOGRAPHY ATMOSPHERIC-PRESSURE IONIZATION MASS-SPECTROMETRY IN NATURAL PRODUCT ANALYSIS - EVALUATION AND OPTIMIZATION OF ELECTROSPRAY AND HEATED NEBULIZER INTERFACES

A representative set of 46 secondary metabolites of plant and microbia l origin was examined with electrospray and atmospheric pressure chemi cal ionization MS in both positive and negative ion mode, in order to evaluate the applicability of atmospheric pressure ionization LC-MS as a tool for rapid identification and dereplication of bioactive compou nds in the drug screening process. MS characteristics of different com pound classes were determined on the basis of quasi-molecular ion and other adduct ion responses observed with the two LC-MS interfaces. Int erface parameters and LC mobile phase composition were optimized and a n analytical protocol applicable to a wide range of secondary metaboli tes is proposed.