GENERAL-APPROACH FOR THE ANALYSIS OF VARIOUS ALKALOID CLASSES USING CAPILLARY ELECTROPHORESIS AND CAPILLARY ELECTROPHORESIS MASS-SPECTROMETRY

The analysis of various alkaloid classes employing capillary electroph oresis (CE) and on-line combined CE-mass spectrometry (CE-MS) is descr ibed. A CE method is presented for the analysis of alkaloids without d erivatisation or purification. The separation of four different groups of alkaloids consisting of monoterpenoid indole alkaloids, protoberbe rines/benzophenanthridines, beta-carboline alkaloids, and isoquinoline s from poppy by free zone capillary electrophoresis has been obtained using a 1:1 mixture of 100 mmol l(-1) ammonium acetate (pH 3.1) and ac etonitrile. The influence of alkaloid structure on the electrophoretic mobility is discussed. The CE-MS reconstructed total ion current (RIC ) of the indole- and the opium-type standard alkaloids shows a decreas ed signal-to-noise ratio compared to CE using only UV detection. As ex pected the single-ion traces (or individual mass traces) of the [M+H]( +) ions show higher signal-to-noise ratios than the RIC. The electrosp ray MS data of the alkaloids are dominated by the protonated molecules and the Na+-, and K+-adducts. They display the typical pattern result ing from cluster formation or doubly charged species.