Novel monohydrogenphosphate ion-selective polymeric membrane sensor based on phenyl urea substituted calix[4]arene

A highly selective and sensitive PVC membrane, containing phenylurea substituted calix[4]arene was found to be a suitable ionophore for monohydrogen phosphate (HPO42−) ions that exhibited a Nernstian response (with a slope of −29.4 ± 0.3 mV decade−1). The working concentration range of the electrode was 6.0 × 10−8-1.0 × 10−1 mol L−1 with a detection limit of 2.0 × 10−8 mol L−1. The response time of the sensor in the whole concentration range is very short (<8 s), with a considerable lifetime of at least 15 weeks. The sensor possesses the advantages of short response time, low detection limit and a high selectivity towards a large number of inorganic anions. The developed sensor was used as an indicator electrode in potentiometric titration of monohydrogen phosphate ion with barium chloride. The proposed sensor was successfully applied for the direct determination of monohydrogen phosphate in real life samples.