Oxidative amperometric flow injection determination of cyanide at an electrochemically pre-treated glassy carbon electrode

A flow injection analysis method for determining cyanide amperometrically by oxidation at an electrochemically pre-treated glassy carbon electrode has been developed. The determination was made in an eluent consisting of pH 9 Britton-Robinson buffer using a measurement potential of + 1.00 V versus SCE. The glassy carbon electrode was pre-treated on-line in the same eluent before use by holding it at +1.50 V versus SCE for 15 min and then at –1.00 V for 1 min. Calibration graphs were rectilinear from 1 × 10–5 to 1 × 10–3M cyanide and coefficients of variation (10 determinations) were typically less than 1% except at the lower end of this range.