Abstract
Studies of the chromatographic behavior of vitamin B_<12> on columns of ion exchange resin led the authors to establish a simple method of determination of vitamin B_<12> in vitamin mixtures by using a strongly basic anion exchange resin, IRA-410. The results obtained by this method showed a good accordance with those of microbiological assay. We also confirmed that vitamin B_<12> was not decomposed during the chromatographic procedures of this method.
