一种含毒死蜱的黄瓜冻干粉基质标准物质的研制

目的建立了一种以黄瓜为基质的毒死蜱标准物质的制作方法。方法黄瓜样品经研磨、加标、冷冻干燥、磨粉、混匀、真空包装后,用GB 23200.113-2018检验样品的均匀性、稳定性,并联合多家实验室对黄瓜冻干粉中毒死蜱基质样品定值,同时分析样品的不确定度。结果F-检验法和t-检验法表明在95%置信区间内,样品均匀性、短期稳定性和长期稳定性均达到标准物质要求。采用格拉布斯和柯克伦检验对定值结果进行异常值检验,并对结果进行不确定度评估,样品定值为1.78 mg/kg,不确定度为0.12 mg/kg。结论该样品具有良好的均匀性、稳定性,可作为蔬菜中毒死蜱含量检测使用的标准物质。

Development of a standard substance for freeze-dried cucumber powder matrix containing chlorpyrifos

ABSTRACT: Objective To fill the gap in the standard substance of chlorpyrifos matrix in China, this ex-periment has developed a vegetable-based chlorpyrifos standard substance. Methods After the vegetable samples are ground, spiked, freeze-dried, milled, mixed, and vacuum packed, they are packed with "GB 23200.113-2018 National Food Safety Standard. Determination of 208 pesticides and their metabolites residues in plant-derived foods. Gas chromatography-mass spectrometry method to test the homogeneity and stability of samples, and cooperate with multiple laboratories to detect chlorpyrifos matrix in vegetables Determine the value of the sample and analyze the uncertainty of the sample at the same time. Results The F-test and t-test methods show that within the 95% confidence interval, sample uniformity, short-term stability and long-term stability meet the requirements of standard materials. Grubbs and Cochrane tests were used to test the outliers of the fixed value results, and the uncertainty of the results was evaluated. The fixed value of the sample was 1.78 mg/kg and the uncertainty was 0.12 mg/kg. Conclusion The matrix sample can be used for instrument calibration, laboratory quality control and operator level assessment in the process of chlorpyrifos detection.