Determination of Residues of 3 Methoxyacrylate Fungicides in Coarse Grains by High Performance Liquid Chromatography with Dispersive Liquid-Liquid Microextraction

A method for the determination of residues of 3 methoxyacrylate fungicides, including azoxystrobin, pyraclostrobin and trifloxystrobin, in coarse grains by high performance liquid chromatography with dispersive liquid-liquid microextraction (DLLME) based on natural bioderived solvent was proposed. The sifted sample (1.0 g) was taken, and 800 μL of acetonitrile (as dispersant) was added for vortex. Then 500 μL of the supernatant was taken, and 200 μL of 4-isopropyl toluene (natural bioderived solvent as extractant) was added. After mixing well, the solution was quickly injected into a 10 mL-centrifuge tube containing 5 mL of water and 200 mg of sodium chloride. After centrifugation for 8 min, the centrifuge tube was frozen at -18 ℃, and the upper layer of unsolidified extract was taken for analysis. As shown by the results, linear relationships between values of mass fraction and peak area of 3 methoxyacrylate fungicides were kept in the range of 0.5-100 mg·kg^-1, with detection limit of 0.17 mg·kg^-1. Test for recovery was made on the negative samples of oat, barley, rye, sorghum and millet, giving results in the range of 90.5%-107%, and RSDs (n=5) of the determined values were less than 6.0%.