Application of a dioxime-PVC electrode to potentiometric studies of Cr(III) ion

Document Type : Research Paper




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 electrode
response was studied. The electrode exhibits a Nernstian response over a Cr(III) concentration range of 1.0 x
10 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 limit
of 8.9 x le M. The selectivity coefficient values as determined by separate solution method (SSM) indicate
excellent selectivity for Cr(III) ion over a large number of other ions. Applications of the proposed electrode to
the determination of Cr(III) in real samples and as an indicator for potentiometric titration of Cr(III) ion with
EDTA, are reported.