Influence of Temperature and Solar Radiation on Persistence of Vitamin B12, Thiamine, and Biotin in Seawater1

Ecologically important concentrations of vitamin B12 and thiamine in charcoal-treated, filter-sterilized seawater stored in the dark at 5, 18, 28, and 37 C generally did not change over a 9-week period, although there was some breakdown of B12 at 37 C. Biotin activity under similar conditions generally increased, indicating its decomposition to more active products. Solutions kept at-20 C had unchanged vitamin activity. B12 and biotin in seawater exposed to sunlight were rapidly destroyed. The course of thiamine destruction in sunlight indicated a breakdown to a stable, biologically active product(s)).