ANALYTICAL CONTROL OF CEREAL CROP PROTECTION SYSTEM PESTICIDE RESIDUES IN THE WATER AND AIR

Abstract

Introduction. Chromatographic analysis to develop conditions for determining 9 active substances (prosulfuron and pinoxaden herbicides, thiamethoxam and lambda-cyhalothrin insecticides, azoxystrobin, benzovindiflupyr, cyproconazole, propiconazole fungicides, trinexapac-ethyl plant growth regulator) of the cereal crop protection system in their combined presence was performed using analytical standards from which the initial standard solutions of each of the test compounds were prepared in acetonitrile. Chromatographic analysis of each calibration solution of the mixture was performed 3 times to construct the graphs of dependence between the area of the compound chromatographic peak and its concentration. Quantitative determination of the test compound was performed by the method of absolute calibration (external standard method) and the obtained results were processed by statistical methods.

The aim of the study – development and improvement of analytical control of residual amounts of pesticides in water and air when it used as a part of grain protection system.

Research Methods. The findings allowed us to calculate the retention factor (k) and to construct dependences of relative retention of test compounds on columns C18 and CN on the content of acetonitrile in the mobile phase acetonitrile + 0.1 % aqueous solution of orthophosphoric acid and to continue research on compounds separation in its combined presence as more effective using column 250/4.6 Nucleosil 100-5 C18 and a mixture of acetonitrile + 0.1 % aqueous solution of orthophosphoric acid. According to the results of studying the absorption spectra, in order to improve the chromatograms of water samples and, more particular, air, the wavelength of the UV detector was optimized, which gave a positive result.

Results and Discussion. Conditions for water and air samples preparation for further chromatographic determination of test compounds and optimal conditions for extraction and chromatographic determination of different chemical class pesticides used in the cereal crops protection system. These conditions allow to control pesticides shared content in the water and air sample with limits of detection – 0.001 mg/dm³ and 0.05 mg/m³, respectively i.e., will allow controlling the approved hygienic standards of these compounds in the water and working zone air.

Conclusion. Developed conditions for determining 9 cereal crop protection system pesticides by high-performance liquid chromatography method in its shared presence in water and air samples, can significantly speed up the analysis, reduce costs for analysis performance and improve pesticides monitoring in the environment.