离子色谱法测定牛乳中硫氰酸盐含量的 不确定度评估

Assessment of the uncertainty in determination of thiocyanate content in milk by ion chromatography

中文关键词:  离子色谱法  牛乳  硫氰酸盐  不确定度评估

英文关键词:ion chromatography  milk  thiocyanate  uncertainty assessment

中文摘要:

      目的 建立离子色谱法测定牛乳中硫氰酸盐含量的不确定度评估方法, 找出不确定度的主要影响因素。方法 根据《测量不确定度评定与表示》(JJF 1059.1-2012), 从样品重复测量、样品前处理、标准曲线回归、标准溶液配制以及方法回收率几个方面分别讨论各不确定度分量。通过合成各不确定度分量得到方法的不确定度。结果 8次测定同一牛乳样品中硫氰酸盐含量均值为1.699 mg/kg, 其扩展不确定度为0.063 mg/kg, k=2。结论 标准系列溶液的配制过程对扩展不确定度的影响较大, 是不确定度的主要影响因素。

英文摘要:

      Objective To establish a method for uncertainty assessment of thiocyanate content in milk by ion chromatography, and identify the main influencing factors of the uncertainty. Methods According to “Evaluation and expression of uncertainty in measurement” (JJF 1059.1-2012), the uncertainty components were discussed by duplicate measurement of samples, the pretreatment of the samples, the calibration of standard curve, and the preparation of standard series. The uncertainty of method was obtained by synthesis of the uncertainty components. Results The average concentration of thiocyanat in milk was 1.699 mg/kg with 8 times of duplicate measurement, and its expanded uncertainty was 0.063 mg/kg (k=2). Conclusion The most primary influence factor to expanded uncertainty is the preparation of standard series．