气相色谱法测定大米中马拉硫磷的不确定度评定

Evaluation of Uncertainty for Determination of Malathion in Rice with GC

[目的]对气相色谱法测定大米中马拉硫磷的不确定度进行评定。[方法]建立了气相色谱法测定大米中马拉硫磷的测量不确定的数学模型,分析了不确定度的主要来源,对该方法所得结果的已识别来源的不确定度进行评价,并计算相对合成不确定度和相对扩展不确定度。[结果]该研究测定过程所产生的测量不确定度主要来源于回收率和重复性试验,其他因素影响很小,用该法测得大米中马拉硫磷含量为0.008 58 mg/kg,扩展不确定度为0.000 51 mg/kg(95%,k=2)。[结论]该评价方法及结果对提高马拉硫磷检测数据的可靠性与准确性有一定的指导意义。

[ Objective ] The study was to evaluate the uncertainty of measuring malathion residue in rice with GC. [ Method] The establishment of mathematical model of the measurement of malathion in rice by GC was uneertaln, the main sources of uncertainty were analyzed, the influence of the identified uncertainty of the analytical result was evaluated. And the relative synthesis standard uncertainty and the relative expansion un- certainty were calculated out. [ Result] The measurement uneertainty of the measurement process was mainly derived from the recovery rate and repeatability experiments, other factors were very small. The method for measuring the content of rice malathion was 0. 008 58 mg/kg,the expanded uncertainty was 0. 000 51 mg/kg （95 %, k = 2）. [ Conclusion ] The evaluation method and results have certain guiding significance to improve the reliability and accuracy of the detection data of malathion.