Determination of Imidacloprid, Carbendazim and Thiophanate-methyl in Tobacco by High Performance Liquid Chromatography

The residues of three pesticides (imidacloprid, carbendazim, thiophanate-methyl) in tobacco leaves were analyzed by using high performance liquid chromatography. The samples were distilled by acetone/water (v/v=1:1), extracted by dichloromethane and analyzed by using UV detector at 270nm. The liquid phase was methanol/ water(60:40). The analytical results showed that the recovery ratios of imidacloprid was 91.9%-97.1% and the relative standard deviations was 3.97%-10.01%, carbendazim was 92.7%-99.9% and the relative standard deviations was 3.15%-5.37%, thiophanate-methyl was 87.4%-95.3% and the relative standard deviations was 3.05%-4.61%.This method showed simple, good separation effect and high accuracy and precision met the demand of quantitative analysis.