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Determination of chlorfenvinphos in soils by microwave-assisted extraction and stripping voltammetry with an ultramicroelectrode
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Orientador(es)
Resumo(s)
A methodology for the determination of the pesticide chlorfenvinphos by
microwave-assisted solvent extraction and square-wave cathodic stripping voltammetry
at a mercury film ultramicroelectrode in soil samples is proposed. Optimization of
microwave solvent extraction performed with two soils, selected for having significantly
different properties, indicated that the optimum solvent for extracting chlorfenvinphos is
hexane-acetone (1:1, v/v). The voltammetric procedure is based on controlled adsorptive
accumulation of the insecticide at the potential of -0.60 V (vs. Ag/AgCl) in the presence
of Britton-Robinson buffer (pH 6.2). The detection limit obtained for a 10 s collection
time was 3.0 x 10-8 mol l-1. The validity of the developed methodology was
assessed by recovery experiments at the 0.100 µg g-1 level. The average recoveries
and standard deviations for the global procedure reached byMASE-square-wave voltammetry
were 90.2±2.8% and 92.1±3.4% for type I (soil rich in organic matter) and
type II (sandy soil) samples, respectively. These results are in accordance to the
expected values which show that the method has a good accuracy.
Descrição
Palavras-chave
Chlorfenvinphos Mercury film ultramicroelectrode Microwave-assisted solvent extraction Soils
Contexto Educativo
Citação
Editora
Taylor & Francis