Thermometric Titration of Dodecyl Sulfate and Dodecylbenzene Sulfonate Ions with Tetradecyldimethylbenzyl Ammonium

Abstract

A thermometric titration method is described for the determination of dodecyl sulfate (DS) and dodecylbenzene sulfonate (DBS) with tetradecyldimethylbenzyl ammonium (Zephiramine). Heats of the reactions of DS and DBS with Zephiramine are determined to be -84.4 and -19.8 kJ mol^-1, respectively. Addition of polyvinylalcohol (PVA) is found to inhibit the undesired coagulation of the DS- and DBS-Zephiramine precipitates, giving a sharp end point by improving the shape of the titration curves. A few mM solution of DS and DBS can be easily determined within 1 per cent.