Adaptation of the method for determination of the residual amounts of pydiflumetofen in citrus fruits using high-performance liquid chromatography with subsequent testing on real samples

Introduction. Treatment with fungicidal active compounds based on pydiflumetofen is the most effective way to combat fungal infections of plants, the use of which reduces the content of mycotoxins. This is very important mainly when storing food products, in particular citrus fruits, susceptible to contamination with a number of mycotoxins. Material and methods. Some types of citrus fruits (oranges, tangerines) purchased on the consumer market of the Moscow region were used as objects of study. The method is based on the determination of pydiflumetofen using reversed-phase high-performance liquid chromatography with an ultraviolet detector on a diode matrix after extracting the substance from the analyzed citrus samples with a mixture of acetonitrile and water, cleaning the extracts concentrated to an aqueous residue by solid-phase extraction using cartridges. Results. In the developed method, the achieved lower limit of quantification of pydiflumetofen in all studied plant samples (LOQ) is 0.01 mg/kg, the range of measured concentrations is 0.01–10 mg/kg. The method was tested on tangerines and oranges imported from some foreign countries and purchased in the networks of large retail realtors in the Moscow region. The content of pydiflumetofen in the pulp and juice of tangerines and oranges supplied to the Russian Federation is below the detection limit, i.e. less than 0.01 mg/kg, in the peel no more than 0.6 mg/kg, in the whole fruit no more than 0.25 mg/kg. Limitations. Determination of the concentration of pydiflumetofen was carried out in tangerines and oranges, which are citrus fruits. The studies used samples from a limited list of exporting countries. Conclusion. The methodical approach used to determine the content of residual quantities of pydiflumetofen showed positive results in the analysis of citrus fruits. The obtained range of detectable concentrations of pydiflumetofen fully satisfies the existing hygienic standards in force in the territory of the Russian Federation and abroad.