- 期刊
三福林農藥中亞硝基二正丙胺檢驗方法建立
Development of an Analytical Method for N-Nitrosodi-n-propylamine in Trifluralin Pesticides
摘要
本研究建立三福林農藥中不純物亞硝基二正丙胺之液相層析串聯質譜法，以應用於檢測三福林原體及成品中亞硝基二正丙胺含量是否符合我國農藥標準規格準則第三條附表三之二農藥有害不純物之限量規格訂定之限量標準。研究參考液相層析串聯質譜儀應用於其他基質中分析亞硝基二正丙胺之文獻，建立適當分析條件。以乙腈配製不純物標準液，動相為甲酸水溶液搭配乙腈進行梯度設定，選用C18管柱，分析流速0.2 mL/min，並建立多重反應偵測（multiple reaction monitoring，MRM）分析條件。方法檢量線相關係數（r）可達0.99以上。供試樣品2件包含原體及乳劑成品，以乙腈配製，原體加入溶劑後經超音波振盪萃取，再經濾膜過濾後上機，乳劑樣品另以商業化QuEChERS萃取粉末及淨化管淨化，以降低成品中其他成分對質譜儀之汙染，2件樣品均未檢出亞硝基二正丙胺成分。回收率試驗，添加標準品於空白樣品中，以上述樣品配製及淨化步驟製備分析檢液，原體高濃度（0.0001%）及低濃度（0.00004%）回收率分別為107%及98%；乳劑高濃度（0.0001%）及低濃度（0.00002%）回收率分別為81%及84%。方法定量極限原體為0.409 mg/kg、乳劑為0.214 mg/kg，低於法規限量標準。本研究建立之方法符合相關確效試驗標準，可作為國內三福林農藥中亞硝基二正丙胺法定限量標準之參考檢驗方法。
並列摘要
In this study, we established a liquid chromatography tandem mass spectrometry (LC-MS/MS) method to analyze "N-nitrosodi-n-propylamine (NDPA)" impurities in trifluralin pesticides. Our method can be applied to NDPA in both trifluralin technical material and trifluralin formulation to ensure compliance with Schedule 3-2, Article 3 of the Pesticide Standard Specification Guidelines in Taiwan. To establish appropriate analytical conditions for our method, we referred to existing literature that applied LC-MS/MS to NDPA analysis in other matrices. In brief, we prepared the impurity standard solution using an acetonitrile solvent. For the mobile phase, we used a gradient comprising a formic acid solution and acetonitrile. The column was C18, and the flow rate was 0.2 ml/min. We also established MRM analytical conditions. We found that the correlation coefficient of the calibration curve can reach over 0.99. Specifically, the two test samples (technical material and emulsifiable concentrate) were dissolved by acetonitrile solvent, and the technical material sample was extracted by ultrasonic vibration. The test liquid was then filtered and analyzed by LC-MS/MS. For the emulsifiable concentrate, the sample solution was purified using commercial QuEChERS extraction powder and a purification tube. (This purification procedure was performed to minimize contamination by other formulation ingredients affecting mass spectrometry results) No NDPA was detected in either sample. Finally, we also performed recovery tests. For this, we added standard solution to blank samples, and prepared inspection solutions according to the above sample preparation and purification procedures. The high (0.0001%) and low (0.00004%) concentration recovery rates of technical material were 107% and 98%, respectively. The high (0.0001%) and low (0.00002%) concentration recovery rates of emulsifiable concentrate were 81% and 84%, respectively. The limit of quantification for technical material and emulsifiable concentrate were 0.409 mg/kg and 0.214 mg/kg, respectively, and both of these values are lower than legal tolerance standards. The method established in this study is in accordance with related validation guideline. Our method can be used as a reference analytical method to accurately determine NDPA tolerance standards of domestic trifluralin pesticide.