Abstract
Thiamine and O-ethoxycarbonylthiamine (OCET) are converted into thiochrome and O-ethoxycarbonylthiochrome (OCEThc), respectively by treatment with BrCN and a base such as NH_4OH and Na_2CO_3 (acylthiochrome method), whereas both of these thiamine compounds are converted into thiochrome by treatment with BrCN and NaOH (thiochrome method). Studies were made on the selective extraction of OCEThc in the presence of thiochrome, but failed. These findings suggested that fractional determination of OCET and thiamine might be difficult when acylthiochrome method was applied. Fractional determination of OCET and thiamine was successfully performed with usual thiochrome method in combination with thin layer chromatography using MN-300-Cellulose and the solvent system of n-butanol・acetic acid・water (4 : 1 : 5).
