Electrochemical determination of selected pesticides in environmental water samples

Abstract

Electrochemical detection of various contaminants has been widely used as a powerful tool in quality control of food and analysis of environmental samples. In this work, electrochemical procedures for determination of pesticides imidacloprid, metribuzin and metamitron are presented. Thin film layer electrode is used as a working electrode, while chronopotentiometry is applied as an electroanalytical technique. For all analysed pesticides, several solution conditions and instrumental parameters influencing the electroanalytical response of the analytes are examined and optimised in respect to the height of the analytical signals. The obtained analytical signals for the investigated pesticides are the result of irreversible reduction of the analyte on the working electrode surface, and for each analyte one reduction wave is obtained. Under the optimal experimental conditions, proposed chronopotentiometric methods are validated with the respect to linearity, limit of detection, limit of quantification, precision, selectivity, recovery and accuracy. Validated chronopotentiometric methods are applied for analysis of selected pesticides in spiked tap and river water samples. In the analysis of real samples, proposed methods showed to be sensitive and reproducible, fast (1-5 s analysis time), and simple since no complicated sample preparation is needed, and therefore are suitable for routine analysis of pesticides in water samples.