Gas chromatographic analysis of nonionic surfactants by acid cleavage of ether linkages

The gas chromatographic analysis of various kinds of nonionic surfactants has been carried out after chemical decomposition using the mixed anhydride of acetic and p-toluene sulfonic acids which acts as a reagent for cleavage of ether linkages. The gas chromatographic peaks of the reaction products show the alkyl distributions of the hydrophobic groups of ethylene oxide adducts. The alkyl compositions closely agree with those of the starting materials. In this way, the hydrophobic groups of polyoxyethylene alkyl ether, polyoxyethylene alkyl phenol ether, polyoxyethylene alkyl amine, and polyoxyethylene alkyl thioether have been analyzed. At the same time, the hydrophilic group, namely polyoxyethylene group, can be identified in the form of ethylene glycol diacetate.