Chemical and analytical support for the safe use of the fungicide pidiflumetofen in agricultural practice

Introduction. The launch of chemical compositions based on pydiflumetofen, which has already proven itself in global agricultural practice as an effective means of suppressing mycotoxin-producing fungi, on the Russian market has set the task of chemical and analytical support for its safe use. The aim of the study was to develop methods for determining residual amounts of pydiflumetofen in plant products and environmental objects (water, soil, air), which would be available for wide implementation in analytical laboratories, with subsequent use to assess the safety of pesticide application technology on grain crops. Materials and methods. High-performance liquid chromatography with a diode array detector was used for measurements. The sample preparation was based on the classical scheme, which consists of extracting the substance from plant samples and soil with a mixture of acetonitrile and water, followed by purification of the extract using solid-phase extraction (SPE). Concentration of the water sample with its simultaneous purification was performed on SPE cartridges. Sampling of air from the working area was performed using paper filters, and atmospheric air was sampled using XAD-2 sorption tubes. Results. The optimal conditions for the chromatographic separation of pydiflumetofen were selected: a column with a reversed phase (C18), the mobile phase is acetonitrile: water (75:25, by volume), the mode is isocratic, the wavelength is 230 nm. Absolute calibration on a solvent was used. The calibration characteristic is linear in the concentration range of 0.05–0.1 μg/ml, the correlation coefficient is more than 0.99. The lower limit of the detectable concentrations (in grain and soil 0.01 mg/kg, straw – 0.05 mg/kg, water – 0.001 mg/L, air of the working area – 0.01 mg/m3, atmospheric air – 0.005 mg/m3) corresponds to the established hygienic standards. Limitations. In the study, only cereal grains (wheat, barley) were considered as plant products. Conclusion. The developed methods were used to assess the safety of the pesticide application technology on grain crops. No residual amounts of the active substance were detected in the elements of the crop (grain, straw) of winter wheat and spring barley over a two-year observation period. Laboratory studies have confirmed the substance to be retained in the upper layers of soil, which limits its penetration into groundwater. The results of the hygienic assessment of the technology of ground spraying of field crops showed the risk to workers to be acceptable.