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为研究采收前和初烤后烟叶及土壤中三唑酮、霜霉威、稻瘟灵、吡虫啉和仲丁灵残留量的变化,建立了烟叶和土壤中该5种农药残留的超高效液相色谱-串联质谱(UPLC-MS/MS)分析方法。样品经乙腈提取,N-丙基乙二胺(PSA)吸附剂净化,UPLC-MS/MS法检测,采用基质配制溶液绘制标准曲线,内标法定量。结果表明:1烟叶中5种农残的定量限在12.25~37.48μg/kg之间,加标回收率为74%~117%;土壤中5种农残的定量限在0.11~0.34μg/kg之间,加标回收率为78%~107%。2田间试验表明,于烟叶采收前15 d对烟草植株按最大许可使用量施药后,上部、中部叶中吡虫啉、三唑酮(含其残留的转化物三唑醇)和仲丁灵的残留量随时间逐渐减小;霜霉威和稻瘟灵的残留量随时间先增大后减小;初烤后烟叶中5种农药的最终残留量≤2.70 mg/kg,低于CORESTA规定的指导性残留限量(GRLs)。土壤中吡虫啉残留量随时间逐渐减小;三唑酮、稻瘟灵和霜霉威的残留量随时间先增大后减小;仲丁灵残留量随时间有所增加。
In order to study the changes of residues of triadimefon, propamocarb, rice blast, imidacloprid and s-butyl in tobacco leaves and soil before and after harvesting, the ultra-high-performance liquid Phase-chromatography-tandem mass spectrometry (UPLC-MS / MS) analysis. Samples were extracted with acetonitrile, purified with N-propyl ethylenediamine (PSA) adsorbent and detected by UPLC-MS / MS. The standard curves were prepared by using matrix preparation solution and quantified by internal standard method. The results showed that: (1) The limit of quantification of five kinds of pesticide residues in tobacco was between 12.25 and 37.48μg / kg with the recoveries of 74% ~ 117%. The limits of quantification for five kinds of pesticides in soil were 0.11 ~ 0.34μg / kg Between the spike recovery of 78% to 107%. 2 Field experiments showed that imidacloprid, triadimefon (with its residual transformant triadimenol) and sec-trimethoprim were higher in the upper and middle leaves after the tobacco plants were treated at the maximum allowable dosage 15 days before harvesting. The residual amount decreased gradually with time; the residues of propamocarb and rice blast first increased and then decreased; the final residues of five pesticides in tobacco leaves after initial roasting were less than 2.70 mg / kg, lower than that of CORESTA Guiding Residual Limits (GRLs). Residues of imidacloprid in the soil decreased with time. Residues of triadimefon, rice blast, and propamocarb increased first and then decreased with the passage of time. Residues of sec-butyl were increased with time.