application of a dioxime-pvc electrode to potentiometric studies of cr(iii) ion

a pvc membrane cr(iii) ion selective electrode has been constructed using 2h-1,4-benzothioazine-2,3(4h)dione dioxime (btd) as membrane carrier. the influence of membrane composition on the electroderesponse was studied. the electrode exhibits a nernstian response over a cr(iii) concentration range of 1.0 x10 6 to 1.0>< 10-1 m (r = 0.99) with a slope of 19.5 ± 0.5 mv per decade of concentration, and a detection limitof 8.9 x le m. the selectivity coefficient values as determined by separate solution method (ssm) indicateexcellent selectivity for cr(iii) ion over a large number of other ions. applications of the proposed electrode tothe determination of cr(iii) in real samples and as an indicator for potentiometric titration of cr(iii) ion withedta, are reported.