多菌灵在地黄及土壤中的残留动态研究

Residue Dynamics of Carbendazim in Rehmannia glutinosa Libosch and Soil

采用固相萃取法净化、高效液相色谱法(HPLC)测定,建立了地黄及土壤中多菌灵残留的检测方法,并研究了多菌灵在地黄块根、叶片及土壤中的消解动态和最终残留情况。结果表明:多菌灵在0.017 5～5.18μg/mL范围内峰面积与质量浓度间有良好的线性关系,检出限为0.046ng,定量限为0.092 mg/kg,其在地黄块根、叶片以及土壤中的添加回收率分别介于86.42%～95.07%、84.73%～89.95%和90.54%～95.61%,相对标准偏差为1.38%～3.68%、2.71%～7.72%和3.63%～7.76%。多菌灵在地黄块根中的消解方程为C=0.052 0e-0.100 8t,半衰期6.88d;在叶片中的消解方程为C=3.584 3e-0.259 2t,半衰期2.67d;在土壤中的消解方程为C=0.051 6e-0.074 0t,半衰期9.36d。施药14d后,多菌灵在地黄块根、叶片及土壤中的残留均降至0.1mg/kg以下,未超出我国规定的多菌灵在果蔬上的最大允许残留量(0.5mg/kg)。

A solid phase extraction（SPE） coupled to high performance liquid chromatography（HPLC） method was conducted to reveal residual dynamics and eventual residue of carbendazim in Rehmannia glutinosa Libosch and soil.The results indicated that the calibration curve of carbendazim was linear in the range of 0.017 5-5.18 μg/mL,the limit of detection was 0.046 ng,and the limit of quantification was 0.092 mg/kg.The spiked recoveries of carbendazim were in the range of 86.42%-95.07%,84.73%-89.95% and 90.54%-95.61%,and the relative standard deviations（RSD） were in the range of 1.38%-3.68%,2.71%-7.72% and 3.63%-7.76%,respectively,in root tubers and leaves of R.glutinosa Libosch,and soil.The kinetic equations of carbendazim degradation in root tubers and leaves of R.glutinosa Libosch were C=0.052 0e-0.100 8t and C=3.584 3e-0.259 2t,and the half lives were 6.88 d and 2.67 d,respectively.The kinetic equation of carbendazim degradation in soil was C=0.051 6e-0.074 0t,and the half life was 9.36 d.The final residues of carbendazim in root tubers and leaves of R.glutinosa Libosch,and soil were all dropped below 0.1 mg/kg at 14 days post application of the fungicide.