《分析方法目的的适宜性》在农药残留检测领域的应用

Application of The fitness for purpose of analytical methods in the field of analyzing pesticide residues

中文关键词:  实验室方法确认指南  液相色谱-串接质谱仪  丙草胺

英文关键词:A laboratory guide to method validation  liquid chromatography-tandem mass spectrometry  pretilachlor

中文摘要:

      目的 以液相色谱-串接质谱联用仪(liquid chromatography-tandem mass spectrometry, LC-MS/MS)检测茶叶中丙草胺为例, 按照欧盟《分析方法目的的适宜性》(以下称指南)进行方法确认。方法 茶叶中的丙草胺用乙腈提取, 经过石墨化炭黑和N-丙基乙二胺净化后, 用液相色谱-串接质谱联用仪检测。结果 目标化合物在0.039~0.625 μg/L范围内线性关系良好, 相关系数(r2)大于0.999。茶叶中丙草胺的定量限(LOQm)和检出限(LODm)分别为0.045、0.015 μg/kg。不同加标浓度样品(LOQ、2LOQ、10LOQ)的平均回收率为90.0%~102.0%。重复性相对标准偏差为2.71%; 中间精密度相对标准偏差为3.67%。结论 本研究简化了样品前处理的方法, 按照《指南》定义的9项要素对更改后的方法进行确认, 并介绍了具体步骤。相关的检测结果均符合《指南》的要求, 为单个实验室的方法确认和标准操作程序的编制提供参考。

英文摘要:

      Objective Taking the analysis of pretilachlor in tea by use of liquid chromatography-tandem mass spectrometry (LC-MS/MS) as example, to carried out method validation in light of the Eurachem Guide—The fitness for purpose of analytical methods (referred as The Guide). Methods Pretilachlor in tea was extracted with acetonitrile. After purification with graphitized carbon black (GCB) and N-propylethylenediamine (PSA), pretilachlor in the extraction was determined by LC-MS/MS. Results The calibration curve showed a good linearity in the ranges of 0.039-0.625 μg/L with the correlation coefficient greater than 0.999 (r2>0.999). The limit of quantification (LOQm) and limit of detection (LODm) were 0.045 and 0.015 μg/kg, respectively. The average recoveries varied from 90.0% to 102.0% at 3 spiked levels (LOQ, 2LOQ and 10LOQ) with the relative standard deviations of 2.71% (repeatability) and of 3.67% (intermediate precision). Conclusion This study simplified the method of sample pretreatment, confirmed the modified method according to the 9 elements defined in The Guide, and introduced the specific steps. The relevant test results are in line with the requirements of The Guide, which can provide a reference for method validation in single lab and the draft of standard operating procedures in labs.