C18 Reversed-Phase Liquid Chromatography Column Coupled with Ion Chromatography: a Method for the Determination of Trimethylamine Hydrochloride Residues in Cationic Etherifying Agent

This method demonstrated an ion chromatography (IC) technique with suppressed conductance for the determination of residual trimethylamine hydrochloride (TMAC) in the synthesis of 3-chloro-2-hydroxypropyl trimethyl ammonium chloride (CHPTAC). The key point is the silicon-based C18 reversed-phase liquid chromatography column coupled with ion suppression chromatography for analysis. Due to the matrix of CHPTAC having a significant effect on the accuracy of ion chromatography (IC) determination, a standard addition method was used to calculate the influence of the matrix in CHPTAC samples on the accuracy of detection substances. The detection limit of this method was 0.1 μg mL −1 (signal to noise, S/N = 3), and the recovery of standard addition of TMAC was in the range 98.0–102.0%. The relative standard deviation (RSD) ranged from 0.8 to 1.26%, which showed that this optimized method has a good measurement precision and demonstrates satisfactory reliabilities. The experimental results showed that using a C18 reversed-phase chromatographic column can significantly reduce the problem of IC being susceptible to matrix effects and significantly improve the detection sensitivity of IC on the detection of TMAC in CHPTAC.