RESUMO
This paper presents the use of square wave voltammetry (SWV) and square wave adsorptive stripping voltammetry (SWAdSV) in conjunction with a cyclic renewable silver amalgam film electrode (Hg(Ag)FE) for the determination of aclonifen in spiked water samples. A reduction peak at -0.65 V versus Ag/AgCl was obtained in the selected buffer (borax buffer with pH 9.2), exhibiting the characteristics of an irreversible reaction. The effect of square wave (SW) frequency, SW amplitude and step potential, as well as accumulation parameters (time and potential) were studied to select the optimal experimental conditions. The calibration curve was linear in the aclonifen concentration range from 1.0×10(-7) to 1.0×10(-6) mol L(-1) and from 1.0×10(-8) to1.0×10(-7) mol L(-1) for SWV and SWAdSV, respectively. The detection and quantification limits were found to be 3.1×10(-8) mol L(-1); 1.0×10(-7) mol L(-1) and 2.9×10(-9) mol L(-1); 9.6×10(-9) mol L-1 for SWV and SWAdSV, respectively. The proposed method was applied successfully in the determination of aclonifen in spiked water samples. The developed procedure can be adequate at least for screening purposes, where positive results should be confirmed by more selective method.
