Flow injection method for preconcentration and polarographic determination of copper in water

Abstract

The analytical application of a simple polarographic Row through cell, which was previously designed for the continuous polarographic analysis of organic compounds in pharmaceuticals and urine, is proposed in this work for the determination of copper in diluted water samples. The cell contains a conventional dropping mercury electrode (DME), a mercury pool and a platinum wire as the working, reference and counter electrodes, respectively Enrichment of the analyte, previous to the polarographic continuous determination. was necessary and was achieved by using a microcolumn containing Chelex-100, located in the loop of the injection valve. The Row through detector can be used either amperometrically, under continuous Row operation, or voltammetrically in quiet solution. under continuous flow-stopped flow mode. Under continuous Row operation of the cell, after a preconcentration rime of 3 min, the preconcentration factor was calculated to be 90. with a limit of detection of 9.5 ng/ml and a sampling rate of 15 h(-1). The repeatability of the analytical signals, expressed as RSD, was always lower than 2.1%. Validation of the method was carried out by analysis of certified reference materials, and the recovery was 101.96 +/- 1.38%.