Gas Chromatographic Analysis of n-Dodecylguanidin Hydrochloride Used as Sanitary Finishing Agent in Fabrics

A gas chromatographic method was developed for the determination of n-dodecylguanidine hydrochloride used as a sanitary finishing agent in fabrics. The analytical procedure is as follows : the fabrics were refluxed in 80% methanol solution containing 0.5% of sodium hydroxide for 1 h. The mixture was filtered and the filtrate was made up to 50 ml with methanol. The n-dodecylguanidine was obtained from an aliquot of the sample solution by extraction with chloroform under alkaline conditions and then derivatized to 2-n-dodecylamino-4, 6-dimethylpyrimidine by refluxing with acetylacetone for 1 h in toluene. The reaction mixture was evaporated to dryness under reduced pressure. The residue was dissolved in ethanol. The pyrimidine derivative was measured by gas chromatography with a column of 5% diethyleneglycol succinate on Chromosorb W AW. This method was applied to the determination of n-dodecylguanidine hydrochloride in commercial men's socks and other textile products.