氯吡嘧磺隆在玉米植株及土壤中的消解动态研究

利用超高效液相色谱-质谱法建立了氯吡嘧磺隆在玉米植株和土壤中的残留分析方法,并研究了氯吡嘧磺隆在玉米植株和土壤中的残留消解动态,对影响残留分析方法的主要参数进行了优化。结果表明,氯吡嘧磺隆标准溶液的线性方程为y=66 535x+747.06(r2=0.999 9),线性范围为10～1 000ng/mL。残留样品采用丙酮提取,乙酸乙酯萃取净化,超高效液相色谱分离,质谱仪检测,外标法定量。该方法在玉米植株和土壤中的最低检测限(LOQ)均为0.002mg/kg,当样品中氯吡嘧磺隆的添加水平为0.05～0.2mg/kg时,采用该方法测得植株和土壤中的平均回收率分别为85.16%～88.13%和87.65%～91.37%,相对标准偏差(RSD)分别为1.92%～2.09%和1.16%～2.61%。消解动态试验表明,氯吡嘧磺隆的残留量随时间延长而降低,消解动态曲线符合一级动力学方程,在植株和土壤中半衰期分别为0.78～0.97d和7.00～16.90d。试验结果显示,氯吡嘧磺隆在玉米田中属较易降解的农药。

Degradation Dynamics of Halosulfuron Methyl in Corn Plant and Soil

An ultra performance liquid chromatography-mass specteometry(UPLC-MS) method was developed to determine halosulfuron methyl residue in corn plant and soil,and the degradation dynamics of halosulfuron methyl in corn plant and soil were studied.Under the optimum conditions,the performance of the method was evaluated.The results showed that the linear equation of standard solution was y = 665 35x+747.06(r2 =0.999 9) with the linearity of 10-1 000 ng/mL,the average fortification recoveries of halosulfuron methyl in corn plant and soil varied from 85.16% to 88.13% and 87.65% to 91.37%,with relative standard deviation(RSD) of 1.92%-2.09% and 1.16%-2.61% when halosulfuron methyl was spiked at 0.05-0.2 mg/kg level in various matrixes,and the limits of quantification(LOQ) in corn plant and soil were 0.002 mg/kg.Furthermore,the degradation dynamics indicated that halosulfuron methyl degraded continuously and the curve of degradation dynamics followed the first-order kinetics equation.The half-lives of halosulfuron methyl in corn plant and soil were 0.78-0.97 d and 7.00-16.90 d,respectively.The results showed that halosulfuron methyl was easy to degrade in corn plant and soil.