Chromatographic determination of riboflavin and its derivatives in food

Three elution methods on two different reversed-phase C-18 columns were dev eloped to determine flavin(1) derivatives in raw egg white, raw egg yolk, e gg powder, pasteurised milk, fermented milk products and liver (chicken, ca lf and pig). Additionally, 11 thin-layer chromatography solvent systems wer e used to confirm presence of flavins detected in assessed products. It was found that an Alphabond C-18 column was not as effective as a Symmetry C-1 8 column. Method A (mobile phase gradient of methanol-0.05 M ammonium aceta te, pH 6.0 applied on an Alphabond C-18 column) can be used for determinati on of flavin adenine dinucleotide, flavin mononucleotide, riboflavin 4',5'- cyclic phosphate, riboflavin, 10-formylmethylflavin and 10-hydroxyethylflav in in products that do not contain 7 alpha-hydroxyriboflavin. Method B (mob ile phase gradient of methanol-demineralized water, on an Alphabond C-18 co lumn) can be useful to separate flavin coenzymes from other flavin compound s or to confirm the presence of 7 alpha-hydroxyriboflavin and 10-hydroxyeth ylflavin in analysed samples. Method C (mobile phase gradient of methanol-0 .05 M ammonium acetate, pH 6.0, on a Symmetry C-18 column) allows separatio n of all flavins detected in tested products: flavin adenine dinucleotide, flavin mononucleotide, riboflavin 4',5'-cyclic phosphate, riboflavin, 10-fo rmylmethylflavin, 10-hydroxyethylflavin, 7 alpha-hydroxyriboflavin, ribofla vin-beta-D-galactoside and riboflavin-alpha-D-glucoside. (C) 2000 Elsevier Science BN. All rights reserved.