芹菜中7种农药及其代谢物基体标准物质的制备

目的 制备芹菜中7种农药及其代谢物基体标准物质。方法 将空白芹菜样品粉碎、冷冻干燥制成干粉后,与农药标准溶液混匀,搅拌挥发干后制得基体标准物质,经均匀性和稳定性检测,由8家实验室联合定值,并进行不确定度评估。结果 基体标准物质中7种农药及其代谢物的特性值为0.497～0.502 mg/kg,扩展不确定度为0.0079～0.0123 mg/kg,均匀性良好,可稳定保存至少12周。结论 通过该方法制备的基体标准物质均匀性和稳定性良好,定值结果可靠,可用于检测过程的质量控制、检测方法开发、实验室能力验证等领域。

Preparation of 7 pesticides and their metabolites matrix reference materials in celery

Objective To prepare 7 pesticides and their metabolites matrix reference materials in celery. Methods Blank celery samples were homogized and freeze-dried to obtain dry powder into which pesticide standard solutions were fortified and thourghly mixed. Finally, matrix reference materials were obtained after solvent evaporation. After homogeneity and stability studies, coordinated values were determined by 8 laboratories, and the uncertainty was evaluated. Results The characteristic value of the reference material were 0.497?0.502 mg/kg, the value of the expanded uncertainty were 0.0063?0.0110 mg/kg, the homogeneity was good and the stability was more than 12 weeks. Conclusion The matrix reference material prepared by this method has good homogeneity and stability, which can be used in the quality control of testing processes, the development of testing method and laboratory proficiency testing, etc.