30%毒死蜱微乳剂在甘蓝及土壤中的残留动态研究

Study on Residual Dynamics of 30% Chlorpyrifos Micro-Emulsion in Cabbage and Soil

利用气相色谱(配FPD检测器)分析测定了30%毒死蜱微乳剂在甘蓝和土壤中的残留消解动态和最终残留量。毒死蜱色谱峰面积与质量浓度在0.01～0.5 mg/L范围内呈良好的线性关系,相关系数r2为0.9992。甘蓝和土壤中毒死蜱的最低检出浓度均为0.005 mg/kg,在0.01,0.02,0.1 mg/kg 3个添加水平下,甘蓝及土壤中毒死蜱的平均回收率分别为80.1%～96.4%和82.1%～98.7%,变异系数分别为1.2%～5.0%和2.5%～3.3%(n=10)。残留消解动态的结果表明:毒死蜱在甘蓝中的半衰期为5.8～10.5 d,在土壤中的半衰期为8.0～10.5 d。毒死蜱在收获期甘蓝及土壤中最终残留量均低于我国规定的限量值(1.0 mg/kg)。

A gas chromatography （ equipped with FPD ） method for determination of dynamics of dissipation and final 30% chlorpyrifos micro-emulsion residues in cabbage and soil was described. The results showed that chlorpyrifos presented good linearity （r2=0.999 2） at the range of 0.01-0.5 mg/ L. The lowest chlorpyrifos concentration able to be detected was 0.005 mg/kg in cabbage and soil. When the standard being added in three level （0.01, 0.02, 0.1 mg/ kg）, the recoveries of chlorpyrifos were 80.1%-96.4% and 82.1%-98.7% in cabbage and soil, the coefficient of variation were 1.2%-5.0% and 2.5%-3.3%, respectivly. The dynamic residual digestion of chlorpyrifos results showed that the half life period of chlorpyrifos was 5.8-10.5 d in cabbage, 8.0-10.5 d in soil. The limited concentration of chlorpyrifos was lower than the requirements of China＇s limited value at harvest-time in cabbage and soil（1.0 mg/kg）.