Many kinds of pesticides have been developed and used to yield a good harvest but the residues in agricul-tural products cause health problems. It is important to keep watch on these residues by using adequate methods...Many kinds of pesticides have been developed and used to yield a good harvest but the residues in agricul-tural products cause health problems. It is important to keep watch on these residues by using adequate methods of analysis. Pretreatment such as gel permeation chromatography (GPC) or column chromatography is often needed for the quantitative analysis of pesticide in agricultural products by conventional methods such as gas chromatography/low resolving power mass spectrometry (GC/LRMS). However, these pretreat-ments need a lot of work and take time. New methods saving the necessity of these pretreatments have been desired. We have applied selected reaction monitoring (SRM) to quantitatively determine cypermethrin residues in Perilla frutescens samples and compared the results with LRMS and HRMS in SIM mode. A background peak caused by the matrix overlapped the cypermethrin peak in the analysis using LRMS. SRM and HRMS in SIM mode provided chromatograms without matrix interference. The high selectivity of the product ion (m/z 127) produced from precursor ion (m/z 163) isolated the target peaks from the matrix peaks when using SRM. This method eliminates the pretreatment step, thus saving time and simplify ing the ana-lytical process.展开更多
文摘Many kinds of pesticides have been developed and used to yield a good harvest but the residues in agricul-tural products cause health problems. It is important to keep watch on these residues by using adequate methods of analysis. Pretreatment such as gel permeation chromatography (GPC) or column chromatography is often needed for the quantitative analysis of pesticide in agricultural products by conventional methods such as gas chromatography/low resolving power mass spectrometry (GC/LRMS). However, these pretreat-ments need a lot of work and take time. New methods saving the necessity of these pretreatments have been desired. We have applied selected reaction monitoring (SRM) to quantitatively determine cypermethrin residues in Perilla frutescens samples and compared the results with LRMS and HRMS in SIM mode. A background peak caused by the matrix overlapped the cypermethrin peak in the analysis using LRMS. SRM and HRMS in SIM mode provided chromatograms without matrix interference. The high selectivity of the product ion (m/z 127) produced from precursor ion (m/z 163) isolated the target peaks from the matrix peaks when using SRM. This method eliminates the pretreatment step, thus saving time and simplify ing the ana-lytical process.
文摘目的 通过研究高效氯氰菊酯与德国小蠊Na K ATPase活性水平的量效与时效关系 ,进一步完善高效氯氰菊酯作用机制的研究 ,为德国小蠊的防制工作提供理论基础和方法参考。方法 参照国标GB 13917 1～ 13917 8- 92《农药登记卫生杀虫剂室内药效试验方法》喷施一定剂量不同浓度的高效氯氰菊酯 ,用ATP酶测定试剂盒测定德国小蠊Na K ATPase活性。结果 4 8h内高效氯氰菊酯对德国小蠊Na K ATPase活性的抑制作用呈浓度梯度效应 ,高效氯氰菊酯的浓度与德国小蠊 72h的死亡率和 14 4h内对Na K ATPase活性的抑制时效呈正相关。结论 Na K ATPase是高效氯氰菊酯的作用靶标之一 ,Na K ATPase敏感度降低而产生的靶标抗性可能是德国小蠊对高效氯氰菊酯产生抗药性的重要原因之一。
