DETERMINATION OF 2,4-D IN SOME FOOD PRODUCTS (MILK, EGGS, LIVER, KIDNEYS) BY CHROMATOGRAPHY METHODS
The modern technique for the determination of 2,4-D, that belongs to global environmental pollutants, including the use of the technology of sample preparation - dispersive solid-phase-liquid extraction (QuEChERS), new for products of animal origin, has been developed. The sample preparation procedure includes the steps of: preliminary freezing of the sample to be analyzed, extraction with acetonitrile containing 1% acetic acid in the presence of MgSO4 and NaCl, purification by dispersive solid-phase extraction using a mixture of sorbents based on primarysecondary amine, octadecylsilane and graphitized carbon black, the freeze of the solution - at the last stage. Using the proposed technique allows to isolate the desired component from a matrix with a high content of animal fat into a selected organic solvent with high efficiency, that made it possible to expand significantly the arsenal of analytical equipment used to detect residual amounts of 2,4-D in food products of agricultural production, for example milk, eggs and offal (liver, kidney): tandem liquid mass-spectrometry (HPLC-MS/MS), gas-liquid chromatography with mass-selective and electron-capture detectors (GLC-MSD, GLC-ECD). The lower limit of the quantitative determination is 2,4-D: 0,005 mg/kg for milk and eggs, 0.05 mg/kg for the liver and kidneys. Completeness of extraction is 85-94%, RMS of repeatability is 3,4-11,4%.