Bismuth(III)-selective membrane electrode based on inorganic ion exchanger

Abstract

Polyvinyl chloride (PVC) based membrane electrodes of antimony(III) silicate were prepared using different plasticizing materials like dibutyl phthalate (DBP), dioctylphthalate (DOP), dibutyl(butyl)phosphonate (DBBP) as plasticizers and sodium tetraphenylborate (NaTPB) as plasticizing solvent mediator and 1-chloronaphthalene (CN) as an anion excluder for Bi 3 + selective sensors. The inorganic ion exchanger based membrane electrode exhibits linearity over a wide concentration range of 2.0 x 10 - 6 - 1.0 x 10 - 1 mol dm - 3 with a slope of 29.6 mV decade - 1 of activity. The electrode assembly works between pH 2.0-7.0, exhibits a fast response time of 20 s and performs satisfactorily over a period of two months with good reproducibility. Excellent selectivity of the order of 10 - 3 over a number of cations and quantitative determination of bismuth(III) in pharmaceutical preparations demonstrates the utility of the proposed sensor.