Online Monitoring of Trace Copper (II) in Environmental Waters

Based on the fact that copper can catalyze the fading reaction of neutral red reduced by hydrogen peroxide using the alanine as a sensitizer in NH4Cl-NH3•H2O medium (pH 8.0), a method was developed for online monitoring of trace copper in environmental waters by flow injection catalytic spectrophotometry. The experimental conditions were optimized. Under optimum conditions, the linear range of the proposed method was between 1.0 µg/L to 125 µg/L and the correlation coefficient of standard curve was 0.9995. The detection limit of the proposed method was 0.11 µg/L. The relative standard deviation of 2.7% and 1.5% was obtained by injecting 15.00 µg/L and 100.00 µg/L copper of standard solution respectively (n=8). The proposed method had been applied to determination of trace amounts of copper in environmental waters. The results were in good agreement with those obtained by atomic absorption spectrophotometry (AAS)