A GC–MSD method for analysis of dimethyl sulfate in palm oil‐based esterquat

Abstract

AbstractDimethyl sulfate (DMS) is a quarternizing agent for esteramine used for the synthesis of esterquat. To date there is no reliable published method for quantification of DMS in palm‐based esterquat. Esterquat is used in the formulation of personal care and textile cleaning. The process of quaternization is usually incomplete and there will be unreacted DMS. This work presents a new simple method involving solvent extraction of DMS followed by analysis with gas chromatography–mass spectrometry detector to quantify the unreacted DMS. This method was validated as per International Council for Harmonization requirements. This novel method showed good repeatability (relative standard deviation [RSD] < 5%) and inter‐day with different analyst reproducibility (RSD < 5%). The limits of detection and quantification were 5 and 10 μg mL−1, respectively. The accuracy of the method was evaluated by the analysis of spiked samples and it was found that good recovery was found at spiking levels of 20, 30, and 50 μg mL−1 with % recovery falling within the 80%–120% acceptable limit. However, at 10 μg mL−1, the percentage recovery was slightly below the recommended limit.