Determination of chromium(VI) in electronics materials using trioctylamine modified carbon paste electrode.

A trioctylamine (TOA) modified carbon paste electrode (TOA/CPE) was firstly utilized to determine Cr(VI) in electronics materials. The effects of preconcentration conditions, that is, TOA amount and accumulation time on Cr(VI) accumulation were examined and the optimum experiment conditions for the determination were identified. A sensitive reduction peak in the stripping voltammogram at -0.45 V, a characteristic of trace Cr(VI), was detected when the accumulation time was 10 min. Under optimized conditions, TOA/CPE demonstrated an enhanced sensitivity for Cr(VI), providing a low detection limit (S/N = 3) at 3.4 x 10(-9) M. Interference studies also displayed high selectivity of the TOA/CPE for Cr(VI); this electrode can accurately determine Cr(VI) in the presence of Cr(III) (600-fold concentration) and other interfering cations.