Potentiometric Determination of Trace Amounts of Aluminium Utilizing Polyvinyl Chloride Membrane and Coated Platinum Sensors Based on E-N′-(2-Hydroxy-3-methoxybenzylidene) benzohydrazide

Abstract

Abstract This paper describes the construction and performance characteristics of novel polyvinyl chloride membrane (PME) and coated platinum (CPtE) aluminium (Al) ion selective electrodes based on E-N′-(2-hydroxy-3-methoxybenzylidene) benzohydrazide. The electrodes exhibited linear responses with near Nernstian slopes of 19.9 ± 0.3 (PME) and 20.1 ± 0.4 (CPtE) mV/decade of activity within the Al3+ ion concentration range of 3.0 × 10–7 to 1.0 × 10–2 M for the PME and 1.0 × 10–7 –1.0 × 10–2 M for the CPtE. These sensors were applicable in a pH range of 3.0 to 7.0. The LODs of the PME and CPtE were 1.7 × 10–7 and 5.6 × 10–8 M, respectively. They had a response time of less than 10 s and could be used practically for a period of at least 2 months without measurable divergence in results. The isothermal temperature coefficient of the PME was 1.12 × 10–3 V/°C, and it can tolerate partially nonaqueous media up to 25%. The electrodes showed excellent selectivity towards Al3+ ions in the presence of a wide range of alkali, alkaline earth, and transition metals ions. They were successfully applied for the direct determination of Al3+ ions in tap water, aqueduct water, mineral water, and Al–Mg syrup and as indicator electrodes in potentiometric titration of Al ions with EDTA.