Voltammetric Determination of Cr(VI) in Natural Water in the Presence of Bipyridine Following Its Deposition to the Metallic State
1999; Wiley; Volume: 11; Issue: 16 Linguagem: Inglês
10.1002/(sici)1521-4109(199911)11
ISSN1521-4109
Autores Tópico(s)Water Quality and Pollution Assessment
ResumoA sensitive and selective voltammetric method for determination of traces of Cr(VI) in natural waters in the presence of Cr(III) is presented. The determinations were performed in a flow system. The calibration plots were linear from 5×10–10 to 5×10–9 and from 1×10–10 to 1×10–9 mol L–1 for deposition times of 60 and 300 s, respectively. The relative standard deviations were between 4.8 and 14%. The detection limit estimated as 3σ for low Cr(VI) concentration is 4×10–11 mol L–1 (2 ng L–1). The detection limit obtained in direct analyses of river water is 9×10–11 mol L–1. The influence of metal ions and surface active compounds is also presented. The validation of the method was made by comparing the results of the analyses of tap water by another electrochemical method and by a recovery test for river water.
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