CAPILLARY ZONE ELECTROPHORESIS AND HPLC FOR THE ANALYSIS OF FLUORESCEIN ISOTHIOCYANATE-LABELED FUMONISIN B-1

Because of the presence of charged tricarballylic acid groups, the fumonisins can be separated by electrophoretic techniques. Fluorescein isothiocyanate derivatives of fumonisins B-1 (FB1) and B-2 (FB2) and hydrolyzed fumonisin B-1 were prepared and analyzed by capillary zone electrophoresis (CZE) and reverse-phase high-performance liquid chromatography (HPLC). The limit of detection for FB1 was 2.5 x 10(-14)g (0.025 pg) by CZE and 8 x 10(-10) g (0.8 ng) by HPLC. As little as 4 ng and as much as 20 mu g of FB1 were derivatized for analysis by CZE. Derivatization of amounts of FB1 between 0.2 and 20 mu g yielded excellent agreement when measured by both HPLC and CZE (r(2) = 0.9996). FB1 added to equine serum at a level of 25 ng/mL could be detected after cleanup with an affinity column and analysis by CZE. This first reported application of capillary electrophoresis to the analysis of fumonisins.