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

A 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. © 2023 Wiley-VCH GmbH.