茶叶中滴滴涕农药残留质控样品的制备与评价

目的建立有机氯类农药残留质控样品的制备方法并对制备技术进行评价。方法以茶叶为基质,滴滴涕为目标物,采用基质添加的方式制备质控样品。采用气相色谱-电子捕获检测器法(gas chromatography-electron capture detector,GC-ECD)对质控样品中目标物含量进行测定。通过随机抽样测定以评估样品的均匀性,通过观察样品在12个月内目标物检测结果变化以评估样品的稳定性,通过10家实验室对质控样品协同定值并进行不确定度评估。结果本研究确定了质控样品中滴滴涕的标示值及不确定度。该方法制备的滴滴涕质控样品均匀性和稳定性良好。质控样品便于贮藏、运输且在常温下能够稳定保存12个月。结论本研究确立了茶叶中滴滴涕质控样品研究的可行性,所建立的制备技术可以确保质控样品定值结果的准确性,为有机氯类农药残留质控样品制备方法的开发提供技术支持。

Preparation and evaluation of dichlorodiphenyltrichloroethane quality control samples in the tea

Objective To establish the preparation method of quality control samples for organochlorine pesticide residues and evaluate the preparation technology. Methods Taking tea as matrix and dichlorodiphenyltrichloroethane as target, quality control samples were prepared by adding matrix. Gas chromatography-electron capture detector (GC-ECD) was used to determine the content of target substance in quality control samples. The uniformity of the sample was evaluated by random sampling determination, the stability of the sample was evaluated by observing the changes of the detection results of the target within 12 months, and the quality control samples were jointly set and evaluated by 10 laboratories. Results This study determined the labeling value and uncertainty of dichlorodiphenyltrichloroethane in quality control samples. The dichlorodiphenyltrichloroethane quality control sample prepared by this method had good uniformity and stability. The quality control samples were easy to store and transport and could be stably stored for 12 months at normal temperature. Conclusion This study established the feasibility of dichlorodiphenyltrichloroethane quality control sample research in tea. The established preparation technology can ensure the accuracy of quality control sample setting results and provide technical support for the development of preparation methods for organochlorine pesticide residues quality control samples.