Chromium(III)-selective sensor based on tri-o-thymotide in PVC matrix

Tri-o-thymotide (I) has been used as an clectroactive material in PVC(poly(vinyl chloride)) matrix for fabrication of chromium(III)-selective sensor. The membrane containing tri-o-thymotide, sodium tetraphenyl borate (NaTPB), dibutyl phthalate (DBP) and PVC in the optimum ratio 5:1:7,5:100(w/w) exhibits a working concentration range of 4.0 x 10(-6) to 1.0 x 10 1 M with a Nernstian slope of 20.0 +/- 0.1 mV/decade of activity in the pH range of 2.8-5.1. The detection limit of this sensor is 2.0 x 10(-7) NI, The electrode exhibits a fast response time of 15 s, shows good selectivity towards Cr3+ over a number of mono-, bi- and trivalent cations and can also be used in partially non-aqueous medium (up to 15%, v/v) also, The assembly has been successfully used as an indicator electrode in the potentiometric titration of chromium(III) against EDTA and also to determine Cr(III) quantitatively in electroplating industry waste Samples. (c) 2005 Elsevier B.V. All rights reserved.