Gas Chromatographic Analysis of Sodium Lauryl Sulfate in Soy Sauce

Abstract

A method has been developed for the determination of sodium lauryl sulphate in soy sauce by gas chromatography. Sodium lauryl (La-OH) sulphate in soy sauce is hydrolyzed to lauryl alcohol with concentrated hydrochloric acid. Lauryl alcohol is extracted from soy sauce with ether and evaporated to dryness. Lauryl alcohol contained in the ethanolic solution of the residue is quantitatively determined with a thermal conductivity detector. The gas chromatographic conditions are described. Sodium lauryl sulphate at a concentration of about 50ppm in soy sauce can be detected.