NEONICOTINOID INSECTICIDES/ACARICIDES: THE DETERMINATION OF RESIDUES IN IMPORTED FOOD PRODUCTS
Introduction. This paper presents the results of a study determination of neonicotinoids' residues (thiamethoxam and its metabolite clothianidin) in imported food products (bananas, citrus fruits, tea, and coffee-beans) using tandem liquid-mass spectrometry (HPLC-MS/MS) of the last generation, ionization source, ESI (positive ionization mode). The mode of the MRM with two parent-ion transitions was used for the identification (for quantitative calculation and confirmation for an ionic ratio). Material and methods. The sample preparation procedure was performed on the QuEChERS technology, including extraction, centrifugation, purification dispersion solid-phase extraction, repeated centrifugation. The acetonitrile acidified by acetic acid (1%) was used for extractions from samples of bananas, coffee, and tea, samples of a citrus subjected extractions with acetonitrile. At the extraction stage to the samples of coffee beans and tea, related to products with a low moisture content, water was added in an amount 2 or more times exceeding the mass of the sample. Results. The LLOQ of a thiamethoxam and its metabolite of a clothianidin in the fruits of bananas and citrus fruits -0.01 ppm, tea - 0.05 ppm and coffee beans - 0.02 ppm, with a signal-to-noise ratio equal to 226:1 (thiamethoxam) and 16:1 (clothianidin). The recovery of the extraction, determined from the analysis of model samples with the fortification of substances at four levels on the range of the detected contents, accounтеd for 90-100%, the RSD of repeatability varied in the range of 5.7-8.4%.