Determination of riboflavin, flavin mononucleotide and flavin adenine dinucleotide in biological tissues by capillary zone electrophoresis and laser-induced fluorescence detection

The separation of riboflavin, flavin mononucleotide and flavin adenine dinu cleotide was investigated by capillary zone electrophoresis using laser-ind uced fluorescence detection. In the systematic approach developed, the diff erential electrophoretic mobilities were first maximized by adjusting the p H. Increasing the buffer concentration improved the separation at the expen se of migration times. A buffer consisting of 50 mM phosphate adjusted to p H 8.5 was found to provide a very efficient and stable electrophoretic syst em. Responses were linear within the range 0.1-100 mu mol L-1 and the detec tion limits of B-2 vitamers were 0.23 nmol L-1 or less. The method was succ essfully applied to a variety of biological tissues from different animals.