【摘要】 建立了噻吩磺隆在土壤、玉米和玉米植株中的超声提取、固相萃取净化和高效液相色谱-质谱联用[SPE-HPLC-ESI(+)-MS]残留检测方法,测定了在田间施药条件下噻吩磺隆在土壤中的消解动态及其在土壤、玉米和玉米植株中的最终残留。土壤、玉米和玉米植株样品经乙腈-磷酸盐缓冲溶液(pH7.8)浸泡、涡旋并超声提取后,经固相萃取柱净化,用反相高效液相色谱-质谱检测。结果表明,噻吩磺隆在该方法下的最小检出量为0.2ng,在10倍浓缩倍数条件下的最低检出浓度为2μg/kg,定量限为6μg/kg,平均添加回收率为77.9%～100.4%,变异系数在1.6%～6.5%之间。田间试验结果表明:噻吩磺隆在土壤中的半衰期分别为0.92～1.23d;按推荐剂量施药,距施药时间40d后和玉米收获时,在土壤、玉米和玉米植株中均未检出噻吩磺隆。更多还原

【Abstract】 A SPE-HPLC-ESI(+)-MS method for the determination of thifensulfuron-methyl residues in soil,corn grains and plants was developed.Residue dynamics in soil and the final residues in soil,corn grains and plants were evaluated.The residue of thifensulfuron-methyl in samples(corn grains,plants and soil)was extracted by a mixture of acetonitrile and phosphate buffer(pH 7.8)=2∶8(V/V),vortex and ultrasonic,and then the extracts were adjusted to low pH and passed through a C18 solid phase cartridge under vacuum condition,the elution was concentrated under nitrogen,the determination and quantitation were performed by HPLC-ESI-MS.The minimum detectable amount of thifensulfuron-methyl was 0.2 ng,and the minimum detectable concentration of thifensulfuron-methyl in the samples of soil,corn grains and plants were 2 μg/kg.The average recoveries ranged from 77.9%~100.4%,with variation coefficient from 1.6%~6.5%.The results of two-year field trial showed that the half-lives of thifensulfuron-methyl in soil were in a range of 0.92~1.23 days.When the corn field was treated by thifensulfuron-methyl 75% WP at 33.3 g/hm2~50 g/hm2(a.i.25 g/hm2~37.5 g/hm2)one time at corn 2~3 leaf growth period,the residues in soil,corn grains and plants were less than 2 μg/kg at 40 or 80 days after application.更多还原