Métodos analíticos para avaliação e controle de vanádio e cobre em água de mar e efluentes de refinaria de petróleo.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2003

RESUMO

In the present paper a procedure for preconcentration and determination of vanadium and copper in seawater using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) was proposed. It was based on solid phase extraction of vanadium(V) and copper(II) ions as PAN complexes by active carbon. The optimization process was carried out using two-level full factorials and Doehlert matrix designs. Four variables (PAN mass, pH, active carbon mass and shaking time) were regarded as factors in the optimization. Results of the two-level full factorial design 24 with 16 runs for vanadium extraction, based on the variance analysis (ANOVA) demonstrated that the factors, pH and active carbon mass besides the interaction (pH x active carbon mass) are statistically significant. For copper, the (ANOVA) revealed that the factors PAN mass, pH and active carbon mass and the interactions (PAN mass x pH) and (pH x active carbon mass) are statistically significant. Doehlert designs were applied in order to determine the optimum conditions for extraction. The proposed procedure allowed determination of vanadium and copper with detection limit (3s/S) of 73 and 94 ng L-1, and a precision, calculated as relative standard deviation (RSD) of 1.22 and 1.37 % for concentration of vanadium and copper of 12.50 mg L-1, respectively. The preconcentration factor is 80. The recovery achieved for determination of vanadium and copper in presence of several cations demonstrated that this procedure improved required selectivity for seawater analysis. The procedure was avaliable for some parameters like, the accuracy for vanadium and copper determination in certificated seawater samples (CASS-4), apples leaves (NIST 1515) and peach leaves (NIST 1547), demonstrated recuperations among 92.4% e 105%. This procedure was applied for determination of vanadium and copper in seawater samples collected in sea-shore Salvador City, Todos os Santos Bay and salines effluents samples of Refinery Landulfo Alves of Mataripe. Results showed good agreement with other reported data from literature.

ASSUNTO(S)

preconcentração cobre doehlert quimica analitica vanádio água do mar

ACESSO AO ARTIGO

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