气相色谱法测定蜂蜜中马拉硫磷残留量的不确定度评定

评定气相色谱法测定蜂蜜中马拉硫磷残留量的不确定度。方法 参照JJF 1059.1-2012《测量不确定度评定与表示》和JJF1135-2005《化学分析测量不确定度评定》,建立气相色谱法测定蜂蜜中马拉硫磷残留量的不确定度的数学模型, 对测量过程中各测量不确定度分量进行分析和计算。结果 通过对各测量不确定度分量的计算和合成,蜂蜜样品中马拉硫磷的残留量为0.021 mg/kg, 扩展不确定度为0.0037 mg/kg(k=2)。结论 气相色谱法测定蜂蜜中马拉硫磷残留量的不确定度主要来源为标准曲线的拟合, 其次是样品测量重复性和标准溶液, 而回收率与样品前处理影响较小。

Uncertainty evaluation for the determination of malathion residue in honey by gas chromatography

Objective To evaluate the uncertainty for the determination of malathion residues in honey by gas chromatography. Methods According to JJF 1059.1-2012 Evaluation and expression of measurement uncertainty and JJF 1135-2005 Evaluation of measurement uncertainty in chemical analysis, a mathematical model was established for the uncertainty of determination of malathion residue in honey by gas chromatography, and each uncertainty components in the measurement process were analyzed and calculated. Results By calculating and synthesizing the each measurement uncertainty components, the residual amount of malathion in honey sample was 0.021 mg/kg, and expanded uncertainty was 0.0037 mg/kg (k=2). Conclusion The uncertainty of the determination of malathion residue in honey by gas chromatography is mainly derived from the fitting of standard curve, followed by the repeatability of sample measurement and standard solution, while recovery rate and sample pretreatment have less influence on uncertainty.