A PVC‐Membrane Cationic Surfactant Sensitive Potentiometric Sensor: Potentiometric Determination of Dodecyltrimethyl Ammonium Ion

Abstract

AbstractA potentiometric poly (vinyl chloride) (PVC) membrane cationic surfactant‐selective sensor based on a dodecyltrimethylammonium‐phosphotungstate ion pair as an electroactive material was suggested for the determination of dodecyltrimethylammonium bromide. Membrane optimization studies revealed that the PVC membrane in the composition of 0.5 % dodecyltrimethylammonium‐phosphotungstate ion pair, 69.5 % o‐nitrophenyloctylether and 30.0 % PVC displayed the best potentiometric performance properties. The sensor exhibited a linear response to dodecyltrimethylammonium ions in the concentration range of 1.0×10−6–1.0×10−2 mol L−1 with a detection limit and sensitivity of 5.0×10−7 mol L−1 and 56.6 mV/decade, respectively. The response of the sensor to dodecyltrimethylammonium cation was quite stable, sensitive, selective and rapid (<10 s). The life span of the sensor was found to be about 3 months. The analytical applications of the sensor were successfully carried out with the developed sensor as an indicator electrode for the determination of the end‐point of dodecyltrimethylammonium ions titration and dodecyltrimethylammonium contents of synthetic water samples.