Abstract
Analyses of α-sulfofatty acids may generally be performed by sulfur-determination, S-benzylthi-uronium salt method, chelatometric method, pH titration, semi-micro methylene blue backtitration method (M.B. method) and photometry.
Particularly, α-sulfofatty acid in a reaction mixture, which is contaminated with unreacted sulfur trioxide, fatty acid and carbon tetrachloride can be determined by only two methods, the M.B. method and photometry.
In this paper, the results of the pH titration applied to the analysis of α-sulfofatty acid were described, and newly developed photometric method was compared with the M.B. method.
α-Sulfopalmitic acid was precipitated as copper salt in the aqueous medium, and the copper ion remaining in the solution was determined photometrically. Then the α-sulfopalmitic acid in the sample was calculated.
The results of the proposed and the M.B. methods showed good agreement.
It has been found that the proposed method was applicable to the determination of the other surface active agents.α-Sulfofatty acid reacted with copper sulfate in the mole ratio of 2 : 1.
