Electrochemical Determination of Trifluralin Herbicide Using Silver Solid Amalgam Electrode: Application in Fresh Food Samples

Danielle Gonçalves Filho,Djenaine De Souza

doi:10.21577/0103-5053.20210044

Abstract

This paper reports the use of polished silver solid amalgam electrode (p-AgSAE) allied to square wave voltammetry (SWV) in the development of a simple, sensitive, fast and green electroanalytical methodology for the trifluralin herbicide determination in fresh food samples. The experimental (supporting electrolyte and potential and time accumulation) and voltammetric (pulse frequency, pulse amplitude and scan increment potential) parameters were previously optimized, which were employed in the construction of analytical curves. Therefore, these curves have enabled the calculation of analytical parameters (linearity range, equation of the analytical curves, coefficients of determination, limits of detection and quantification, recovery efficiency, and relative standard deviations for intraday and interday experiments) and they indicated that the use of the p-AgSAE is suitable for determining any contamination by trifluralin. So, the proposed methodology had to minimize the toxic residues due to the use of liquid mercury or the adsorbed products from the redox reaction that promotes passivation in the other solid surfaces. Furthermore, the optimized methodology was used to trifluralin determination in eggplant, carrot, tomato, grape juice and orange juice, and the results indicated that the proposed methodology presented high robustness, stability and sensitivity, good reproducibility, and hence it is applicable for complex samples.

Highlights

In the last years, governmental and health agencies of all world created informative programs, which demonstrate the importance in the consumption of fruits and/or vegetables or minimally processed foods in order to minimize the number of obesity cases and some diseases associated to the consumption of highly processed foods
The pH of the supporting electrolyte can significantly affect the voltammetric responses of organic molecules, mainly nitro pesticides
The pH was previously evaluated using BR buffer with values from 2.0 to 12.0 and square wave voltammetry (SWV) experiments, where it was possible to observe that the peak potential (Ep) of trifluralin moved to more cathodic values with the increase of pH

Summary

Introduction

Governmental and health agencies of all world created informative programs, which demonstrate the importance in the consumption of fruits and/or vegetables or minimally processed foods in order to minimize the number of obesity cases and some diseases associated to the consumption of highly processed foods. Organic foods have gained prominence because they are produced without the use of pesticides, while the traditional cultivation employs pesticides that can contaminate fruits, vegetables, water, and soil. Their determination is commonly performed employing high-performance liquid chromatographic coupled to ultraviolet/visible detector with the use of methanol, which is a highly toxic organic solvent. This chromatography analysis requires preliminary samples preparation steps employing solid-phase extraction (SPE) cartridges.[9,10,11] While, the use of gas chromatography coupled to nitrogen-phosphorus detector implies in the use of several stages of extraction that demands more reagents, and it has high costs and longer time of the analyzes.[12]

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Conclusion