Interaction of Thiamine Hydrochloride (Vitamine B1) with Anionic Surfactants in Aqueous Medium

Abstract

The interaction between thiaminehydrochloride, ThmHCl (Vitamine B₁) and sodium salts of long chain alkyl sulfates, SAS (C₈, C₁₀, and C₁₉,) has been studied in aqueous solution. Conductimetric titration of thiaminehydrochloride with surfactant resulted three distinct regions. Region I and II where complexation, precipitation and separation occurs were of much interest and were investigated in detail. Values of ion-pair association constants and their dependence on surfactant alkyl chain length were determined by standard method. Standard free energy of ion-pair formation was determined for all the three surfactants in the region I. The 1:1 solubility product, and its dependence on surfactant alkyl chain length was determined for region II. Addition of surfactant solution above the critical micelle concentration resulted in the dissolution of the complex forming a clear solution, region III.