Determination of triazoles when used mixed fungicide preparations on their basis

As of 2023, more than 500 pesticides have been registered for use in agriculture in Ukraine, which include active substances (A.S.) from the triazole class. They make up almost half of the total number of fungicides and more than a third of the total number of seed treatments. Among them, the share of mixed preparations is constantly growing: among fungicidal preparations, they already account for more than half, and among seed treatments, for more than two thirds. To determine triazole residues for pre-registration trials, many methods based on gas-liquid chromatography and high-performance liquid chromatography have been developed. For routine analysis, multi-residue "MRM-methods" are used, in particular with sample preparation according to the QuEChERS methodology. In recent years, such methods have also been used in pre-registration trials of pesticides, especially mixed ones. The purpose of this study was to develop and standardize methodological approaches for the determination of residual quantities of triazole-based fungicides to substantiate and control their safe use in agriculture. Gas-liquid capillary chromatography with electron capture and thermionic detectors; gas-liquid chromatography-mass spectrometry; high-performance liquid chromatography with a diode array detector was used in this study. A set of methods for the determination of fungicides, in particular mixed ones, which include active substances from among triazoles and other classes of chemical compounds, has been developed. The methods are based on a combination of various chromatographic methods (gas-liquid and high-performance liquid chromatography, chromatography-mass spectrometry) using the modern QuEChERS sample preparation methodology. The application of the proposed methodological developments allowed to conduct pre-registration trials of new fungicide preparations, in particular mixed ones, and to substantiate the conditions of their safe use in agriculture.