Initial research on the application of the liquid chromatography - quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) method for monitoring pesticide residues in fruits and vegetables

Currently, there are thousands of plant protection chemicals being allowed for use in agriculture. Abuse or improper use of pesticides lead to increase residues in products, exceeding the maximum residue limit according to the regulations. Therefore, the need for developing methods, which can monitor, detect, and identify many pesticides simultaneously is necessary. The liquid chromatography quadrupole-time-of-flight mass spectrometry (LC-QTOF-MS) method has advantage of being able to simultaneously quantify and screen many compounds at once, are being a trend in analytical techniques for analyzing and screening pesticide residues in foods. In this study, the LC-QTOF-MS method was used to quantify 186 pesticides in fruit and vegetable samples. The limit of detection (LOD) for all compounds is 3.0 µg/kg. The recovery is in the ranged of 74.4 -118%, relative standard deviation (RSD) <20%. At the same time, the method was initial researched for nontarget screening by reprocessing previously acquired data without re-injection of the samples. The list of pesticides can be screening, which are up to 500 chemicals, by comparison results with the available high resolution mass spectral library. The screening detection limit of the method (SDL) is 100 µg/kg. The method has been applied to quantify 186 pesticides, and nontarget screening analyse in 160 fruit and vegetable samples in the first 06 months of 2023.