摘要
建立了甲氰菊酯、高效氯氟氰菊酯、高效氯氰菊酯和溴氰菊酯4种拟除虫菊酯类农药在苎麻和土壤中的多残留分析方法,并通过田间试验研究了这4种农药在苎麻和土壤中的残留消解动态和最终残留量。样品采用乙腈提取,PSA、GCB分散固相萃取净化,经气相色谱仪-电子捕获检测器(GC-μECD)测定,外标法定量。在0.05、0.5和5 mg/kg添加水平范围内,4种农药在苎麻中平均回收率为86.5%~108.3%,相对标准偏差≤5.4%,最低检测浓度为0.05 mg/kg;在0.002、0.02和0.2 mg/kg添加水平范围内,4种农药在土壤中平均回收率为89.0%~106.7%,相对标准偏差≤5.9%,最低检测浓度为0.002 mg/kg。消解动态试验表明:4种农药在苎麻和土壤中的消解行为符合一级降解动力学方程,苎麻中半衰期在10.6~15.1 d之间,土壤中在11.0~23.2 d之间。最终残留结果表明,在15~112.5 g/hm^2施药水平下,施药1~2次,施药间隔期5 d,收获期距末次施药间隔5、10、15、20 d时,4种农药在苎麻中的残留量在0.281~4.628 mg/kg之间,土壤中残留量在<0.002~0.196 mg/kg之间。
A method for the determination of 4 pyrethroids pesticides（fenpropathrin, lambda-cyhalothrin, beta-cypermethrin and deltamethrin） residues in ramie and soil had been established. Residual decline and final residues in ramie and soil samples under field conditions were determined. The samples were extracted with acetonitrile, cleaned up with PSA and GCB, and then determined by GC-μECD and external standard method. The average fortified recoveries of 4 pesticides in ramie were 86.5% ~ 108.3% and the relative standard deviation（RSD） was equal to or less than 5.4% at 3 spiked levels（0.05, 0.5 and 5 mg/kg）. The limit of quantification of 4 pesticides was 0.05 mg/kg in ramie. The average fortified recoveries in soil were 89.0%~106.7% and the RSD was equal to or less than 5.9% at 3 spiked levels（0.002, 0.02 and 0.2 mg/kg）. The limit of quantification of 4 pesticides was 0.002 mg/kg in soil. The study of residue dynamics indicated that the curve of decline accorded with the first-order kinetics equation, and the half-life of 4 pesticides in ramie and soil were 10.6~15.1 d and 11.0~23.2 d, respectively. The final residues study showed that when spraying for 1~2 successive times at application dosage of 15~112.5 g/hm^2 at interval time of 5 d, the final residues of 4 pesticides were in a range of 0.281~4.628 mg/kg in ramie and below 0.002~0.196 mg/kg in soil at 5, 10, 15, 20 d after the last spray.
出处
《湖南农业科学》
2016年第3期85-89,共5页
Hunan Agricultural Sciences
基金
国家麻类产业技术体系线虫与病毒防控岗位资助项目(CARS-19-E11)
