IDENTIFICATION OF VITAMIN-B12 AND ANALOGS BY HIGH-PERFORMANCE CAPILLARY ELECTROPHORESIS AND COMPARISON WITH HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

High-performance capillary electrophoresis (HPCE) was compared for the identification and determination of corrinoids (hydroxy-, cyano-, 5'-desoxyadenosyl- and methyl-cobalamin and cyano-cobinamide) with high-performance liquid chromatography (HPLC). The within-run reproducibility of the retention times in HPCE and HPLC were similar (2.4 and 2.2%, respectively). The detection limit in HPCE was 20 mug/ml. HPLC can be used, in combination with radioisotope dilution assay, when very low concentrations (100 pg/ml) have to be determined in biological material. HPCE is more efficient than HPLC for the identification of corrinoids after conversion into the CN-cobalamin and CN-cobinamide forms.