PVC based 5,10,15,20-tetrakis (4-methoxyphenyl) porphyrinatocobalt(II) membrane potentiometric sensor for arsenite

Abstract

PVC based membranes of 5,10,15,20-tetrakis(4-methoxyphenyl)porphyrinatocobalt(II) (TMOPP-Co) ( I) as electroactive material with dibutyl butyl phosphonate (DBBP), dioctyl phthalate (DOP), 1-chloronaphthalene (CN), tri- n-butyl phosphate (TBP) and tris(2-ethylhexyl) phosphate (TEP) as plasticising solvent mediators have been prepared and tried for arsenite determination. The membrane having a composition 150:5:150 (PVC: I:DBBP) exhibited the best results with linear potential response in the concentration range of 7.9 × 10 −5 to 1.0 × 10 −1 M of AsO 2 − with a slope of 28.8 mV/decade. The useful pH range of the sensor is 6.0–10.5. The membrane worked satisfactorily in non-aqueous medium up to 5% (v/v) non-aqueous content. The selectivity coefficient values for mono- and divalent anions indicate good selectivity for arsenite over a large number of anions.