Pesticide Residues Analysis by Electroanalytical Techniques

Abstract

Despite the historical importance of pesticide in crops to control pests, in the last decades its indiscriminate use has been responsible by harmful to human health resulting in diseasesDiseases as cancer and neurological disorders. This allowed the emergence of novel perspectives in pesticide analysis, in which the electroanalytical techniques have been widely used as fast, reliable, sensitive, low-cost methods to identify and quantify these compounds with few or none sample pretreatments, reduced waste generation, possibility of detection of pesticides from different chemical class and in situ detection. In the electroanalytical techniques are measured some electrical properties such as potential, current, resistance, charge among others, which can be related to the concentration and identification of the pesticide of under study. The resulting electroanalytical signals are ever related to the physicochemical properties of pesticides such as the presence of functional groups that enable reduction and or oxidation reactions, presence ionizable hydrogens and the ability of promote a specific enzyme inhibition. This chapter presents the most important advances in pesticidePesticides electroanalysis obtained from the evaluation in the scientific databases over the last 10 years (2009–2019). It was observed the extensive use of potentiometryPotentiometry, amperometryAmperometry, voltammetryVoltammetry, stripping voltammetryVoltammetry, and impedance electrochemical spectroscopy. We reviewed the published works and noticed the predominance in the use of voltammetryVoltammetry, mainly square wave voltammetryVoltammetry, and a considerable increase in the employ of the electrochemical impedance spectroscopyElectrochemical impedance spectroscopy in pesticide Pesticides analysis Analyses . This occurs because the square wave voltammetryVoltammetry permits the acquisition of high analytical sensitivity, while the electrochemical impedance spectroscopyElectrochemical impedance spectroscopy permits the analysis Analyses of pesticidesPesticides without electronic transference. It was observed that the success in the identification and quantification of pesticidesPesticides, from different chemical class, is related to the adequate choice of working electrode material, solvent, supporting electrolyte type and pH values, and also the proper selection of electroanalytical techniqueElectroanalytical techniques and their respective parameters, which will define the sensitivity and selectivity in the pesticidesPesticides analysis Analyses . In this way, the use of electroanalytical techniquesElectroanalytical techniques in pesticide Pesticides analysis Analyses requires previous knowledge about the specificity of each electroanalytical techniqueElectroanalytical techniques, and the main components of the instrumentation, such as the equipment type and the electrochemical cell, which is constituted by ionic and electric conductors. Furthermore, the analysis Analyses of experimental information obtained after an adequate evaluation in the experimental and electroanalytical parameters provides the understanding of the interface electrode/solution, allows the evaluation of the redox potential of functional groups, which leads to a suitable identification and quantification of pesticidesPesticides, even in complex systems like natural waters, soil, and in natura foodsFoods.