PRECONCENTRATION BASED ON COPRECIPITATION USING SILVER CHROMATE AS A CARRIER FOR COPPER DETERMINATION BY FAAS

In the present paper, a preconcentration procedure based in the coprecipitation of copper by silver dichromate (Ag2CrO4) and consecutive determination by flame atomic absorption spectrometry (FAAS) was proposed. The experimental factors were optimized from application of the Doehlert matrix and the conditions set: chromate concentration 5.8 × 10-4 mol L-1, silver concentration 1.1 × 10-3 mol L-1, pH 7.3 and disperser concentration HNO3 0.38 mol L-1. Under these conditions, analytical parameters of the procedure were obtained, with the quantification limits of 0.76 µg L-1, precision (based in the relative standard deviation, RSD %) with values lower than 2.7%, and preconcentration factor of 28. The accuracy of the procedure was given by addition/recovery test in water samples groundwater and mineral, and by comparison with results obtained by ICP-MS. The procedure developed presented be simple, sensitive and low cost, thus can be applied in the preconcentration and determination of copper in several water samples.