[Cyanocobalamin Reference Standard (Control 891) of National Institute of Hygienic Sciences].

Cyanocobalamin was tested for preparation on the "Cyanocobalamin Reference Standard (Control 891)". Analytical data obtained were as follows: loss on drying, 9.77%; infrared spectrum, same as that of the Cyanocobalamin Reference Standard (Control 871); thin-layer chromatography, five contaminants were detected; high-performance liquid chromatography, nine contaminants were detected; assay, 100.00% by JP XI method and 99.79% by HPLC method in terms of the JP Reference Standard (Control 871), respectively. On the basis of the above results, this material was authorized as the Japanese Pharmacopoeia Standard (Control 891).