Chromium(III) ion Selective PVC Membrane Electrode Based on a Schiff base Ligand, 3-Aminoacetophenonethiosemicarbazone

An attempt has been made to develop a highly selective Cr3+-ion selective PVC membrane electrode based on a 5% newly synthesized 3-aminoacetophenonethiosemicarbazone as an ionophore with 62% DBP, 30% PVC and 3% NaTPB as an anion excluder. The electrode exhibits a near Nernstian potential response of 19.7±0.2 mV per decade over a wide concentration range (1.0×10-8 M to 1.0×10-1 M) with a detection limit of 7.4×10-8 between pH 1.5-6.8 with a fast response time (10 s). The selectivity coefficient values were determined by matched potential method (MPM), indicate higher selectivity for chromium(III) ion with improved performance as compared to other carriers reported earlier. The proposed electrode exhibits an adequate shelf life (14 weeks) without any considerable divergence in potentials. Further the electrode was also successfully applied to determine the content of chromium in water samples collected from different sites of river Yamuna in Delhi.