戊唑醇和吡唑醚菌酯在玉米植株和土壤中残留及其消解动态的检测

采用高效液相色谱–串联质谱（LC–MS/MS）方法,分析戊唑醇和吡唑醚菌酯在玉米植株和土壤中的残留及消解动态。土壤样品采用乙腈提取,植株样品采用乙腈和丙酮提取,过膜后采用LC–MS/MS分析。结果表明：戊唑醇和吡唑醚菌酯在土壤和玉米植株中的定量限分别为0.01、0.02 mg/kg,检出限分别为0.001、0.005 mg/kg。当添加水平为0.01~2.00 mg/kg时,戊唑醇和吡唑醚菌酯在土壤和玉米植株中的平均回收率为83.9%~113.3%,相对标准偏差为1.0%~8.0%。消解动态试验结果表明：30%戊唑醇·吡唑醚菌酯悬浮剂按1 050 g/hm2（有效成分315 g/hm2）于玉米苗期施药1次,戊唑醇和吡唑醚菌酯在土壤及玉米植株中的消解动态规律均符合一级动力学方程曲线,戊唑醇在玉米植株和土壤中的消解半衰期分别为5.22、14.10 d,吡唑醚菌酯在玉米植株和土壤中的消解半衰期分别为4.78、13.40 d,二者均属易消解型农药。

戊唑醇在贵州黄壤中的淋溶迁移作用

采用土壤薄层层析法研究戊唑醇在贵州黄壤中的移动迁移能力,结果发现,戊唑醇在在黄壤中的移动迁移能力R值为0.075,属于基本不移动。根据实验结果推断戊唑醇难以通过淋溶作用进入地下水而造成污染;但是其内吸性和持效期长的特点容易造成动物的蓄积毒性。

快速溶剂萃取-气相色谱-质谱法同时测定土壤中环丙唑醇、烯唑醇和戊唑醇

建立快速溶剂萃取–气相色谱–质谱法同时测定蔬菜种植基地土壤中环丙唑醇、烯唑醇和戊唑醇的分析方法。随机采集蔬菜种植基地土壤样品,风干,粉碎,过筛,置于加速溶剂萃取池中用乙腈提取,以丙酮–正己烷混合溶剂净化,净化液置于氮吹仪中吹至近干,用丙酮–正己烷溶液复溶,采用气相色谱–质谱法测定,内标法定量。环丙唑醇、烯唑醇和戊唑醇的质量浓度在0.04~4.0μg/mL范围内与色谱峰面积具有良好的线性关系,相关系数均大于0.995,检出限分别为0.006、0.008、0.013 mg/kg,定量限分别为0.019、0.026、0.040 mg/kg。环丙唑醇、烯唑醇和戊唑醇的平均加标回收率分别为92.3%~99.8%、91.8%~100.3%、96.4%~101.2%,测定结果的相对标准偏差分别为2.62%、2.69%、4.04%。该方法适用于批量土壤样品农药残留的监测。

Influence of Copper on Transport and Dissipation of Lambda-Cyhalothrin and Cypermethrin in Soils

Repeated applications of bordeaux mixture （a blend of copper sulfate and calcium hydroxide） and pyrethroid insecticides （Pys） have led to elevated copper （Cu） and Pys concentrations in vineyard surface soils. To understand the potential influence of Cu on the fate of Pys in the soil environment, we selected two Pys, cypermethrin （CPM） and lambda-cyhalothrin （A-CHT）, and two typical Chinese vineyard soils, Haplic Acrisol and Luvic Phaeozem, as experimental samples. The dissipation experiment was conducted at room temperature in the dark, and the transport of both Pys through the soils was investigated using soil thin-layer chromatography. The results showed that the transport of Pys in both soils increased as the Cu2＋ concentration increased from 0 to 100 mg L-1, and Pys were more transportable in Haplic Acrisol （HA） than in Luvic Phaeozem （LP） under the same experimental conditions. For CPM, only 100 mg L-1 of Cu2＋ significantly （P 〈 0.05） increased Pys transport through both soils relative to water. Lambda-CHT was significantly （P〈0.05） transported through HA by all the Cu2＋ concentrations compared to water, and all but the 1 mg L-1 of Cu2＋ significantly （P 〈 0.05） increased the transport of A-CHT through LP relative to water. However, the dissipation rates of CPM and λ-CHT decreased with the addition of Cu to soils. Our findings suggest that the risk of groundwater contamination by Pys increases in the soils with elevated Cu concentrations.