FACTORS INFLUENCING PERFORMANCE IN THE RAPID SEPARATION OF AFLATOXINS BY MICELLAR ELECTROKINETIC CAPILLARY CHROMATOGRAPHY

Micellar electrokinetic capillary chromatography (MECC) is applied to the high-speed analysis of aflatoxins. Baseline separation of the four common aflatoxins G1, G2, B1 and B2, is accomplished in less than 30 sec. Small (25-mu-m) internal diameter capillaries are found to be critical in maintaining high efficiency under rapid MECC separation conditions. Van Deemter-like plots are generated in order to study the effects of capillary diameter and organic solvent on efficiency under high electric field conditions. Other experimental parameters affecting efficiency are investigated, including buffer concentration, surfactant concentration, and detector time constant. Simple on-column laser-based fluorescence detection, employing helium-cadmium laser radiation at 325 nm for excitation, allows for limits of detection in the range of 0.05 0.9 femtomoles injected for underivatized aflatoxins. Considerations important in the analysis of aflatoxins in real matrices are presented.