A Systematic Approach for the Determination of B-Group Vitamins in Multivitamin Dietary Supplements by High-Performance Liquid Chromatography with Diode-Array Detection and Mass Spectrometry.

This paper describes a practical approach using an LC diode-array detector (DAD) and MS for the quantitation of B-group vitamins (thiamine, riboflavin, nicotinamide, pantothenic acid, pyridoxine, biotin, folic acid, and cyanocobalamin) in multivitamin supplements. The purpose of this study was to optimize the extraction and chromatographic conditions without application of internal standards to determine B-group vitamins in multivitamins. Chromatographic separation on a C18 column was optimized on the basis of chromatographic behavior depending on pH variation of the mobile phase. The optimized methods showed good r values, with RSD values lower than 2.44 and 3.09% for most of the B-group vitamins (except cyanocobalamin) using LC-DAD and LC-MS, respectively. The methods were also proved to be reproducible, with RSD values of 0.96 and 2.48% being obtained with LC-DAD and LC-MS, respectively. In addition, the developed analytical methods for B-group vitamins were validated using certified reference materials and were applied to commercially available multivitamin tablets.