ВОЛЬТАМПЕРОМЕТРИЧЕСКИЙ СЕНСОР ДЛЯ ОПРЕДЕЛЕНИЯ МАЛАТИОНА И ДИАЗИНОНА

The current article suggests a voltammetric method for the quantitative determination of malathion and diazinon using a modified electrode. The method is based on the adsorption concentrating of pesticides onto a graphite-containing electrode modified by polyaniline and a Co (III) chelate complex with 2,2'-dipyridyl. Analytical signals are determined by the recovery of cobalt (III) from mixed-ligand complexes with malathion and diazinon at the peak potentials of 0.65 and 0.47 respectively. The method allows one to determine pesticides within 0.05-1.50 mg / l with the following detection limits calculated by the 3s-criterion: 0.02 mg / l (malathion) and 0.015 mg / L (diazinon). The sensor functions as the sampler, as the sample preserver, and as the indicator electrode. The method has been approved for determining the presence of phosphorus-containing pesticides in natural waters and in acid extracts from soil and plants. The results obtained by the suggested method were compared with the results of determining malathion and diazinon by chromatography method. The developed technique exhibits high sensitivity, instrumentation simplicity, and quickness. The developed electrode allows one to store information for at least 10 days, while the analytical signal changes by no more than 15%. Keywords: pesticides, malathion, diazinon, adsorption voltammetry, modified electrode, polyaniline, cobalt 2,2'-dipyridyl. DOI: http://dx.doi.org/10.15826/analitika.2019.23.3.014 (Russian) V.V. Shelkovnikov, K.Yu. Novolokov National Research Tomsk State University, pr. Lenina, 36, Tomsk, 634050,  Russian Federation