液相色谱法测定土壤中吡虫啉含量的不确定度评定

Assessment of uncertainties in determination of imidacloprid in soil by high performance liquid chromatography

目的对液相色谱法测定土壤中吡虫啉含量的不确定度进行评定。方法对液相色谱法测定土壤中吡虫啉含量的测定过程进行分析,通过建立数学模型计算测试过程中的不确定度分量,最后计算出相对合成标准不确定度和相对扩展不确定度。结果在土壤中吡虫啉含量的测定中,吡虫啉含量为171.8μg/g,其扩展不确定度为5.16μg/g(置信度95%,k=2)。结论液相色谱法测定土壤中吡虫啉含量的测定过程所产生的不确定度主要来源于精密度的检测这个步骤,其他因素的影响相对较小。

Objective To evaluate the uncertainty of measurement results for the determination of imidacloprid in soil by HPLC. Methods The measuring process of determination of imidaeloprid in soil with HPLC was analyzed. The uncertainty components in testing process were calculated through mathematic model. Finally, the relative synthesis standard uncertainty and the relative expansion uncertainty were calculated out. Results The results showed that in this analysis, the expanding uncertainty was 5.16 μg/g （degree of confidence of 95 % , k = 2 ） with imidaclo- prid content of 171.8 Iμ/g. Conclusion It was resulted that measurement uncertainty was mainly derived from the procedures of precision detection. The influence of other factors is relatively little.