Determination of the mothproofing agent Eulan WA (New) in fish tissue using gas-liquid chromatography following extractive methylation

Abstract

A method for the determination of Eulan WA (New)[active ingredient polychloro-2-(chloromethylsulphonamido) diphenyl ether (PCSD)] is described. The PCSDs are extractively methylated using tetrabutylammonium (TBA) ion, which forms ion pairs with sulphonamide at pH 10–12. This ion pair is subsequently back-extracted into the organic phase and methylated using methyl iodide. The methyl derivative of the PCSDs were quantified by gas-liquid chromatography using electron-capture detection. The coefficient of variation (p > 0.05) for perch liver was 4.82 mg kg^–1±5.6% for between-batch extractions. The minimum detectable concentration for a 5-g sample was 0.005 mg kg^–1 of fresh tissue.