Chromium(III) ion selective electrode based on 2H-1,4-benzothioazine-2,3(4H)dione dioxime as a neutral carrier

A poly(vinyl chloride) membrane based on a new a-dioxime derivative as membrane carrier was prepared and investigated as a Cr(III) selective electrode. The electrode exhibits a good potentiometric response for Cr(III) over a wide concentration range 1.0 x 10-6 to 1.0 x 10-1 M with a slope 19.5+0.5 mV/decade and low detection limit of 8.9 x 10-7 M. It has a fast response time < 15 s. The best performance was observed with the membrance having the PVC-ligand-acetophenone-oleic acid composition 6:1:13:1. The proposed electrode works well in a wide p1-1 range 1.5-5.5. The proposed sensor was successfuly used for the determination of Cr(III) ions in samples and real samples and as indicator electrode in potentiometric titration of Cr(III) ion. The application of this electrode for Cr(III) determination in real samples is described. The results obtained with this procedure are in close agreement with those obtained using AA spectrophotometry.