体液中测定吗啡含量的不确定度评定

Evaluation of Measurement Uncertainty for the Determination of Morphine in body Fluids

目的依据测量不确定度的评定原则,对不确定度的评定方法进行探讨,建立液相色谱-质谱联用法测定体液中测定吗啡含量的不确定度分析方法。方法采用液相色谱-质谱联用仪对体液中吗啡含量检测的不确定度进行评定,建立该方法测定体液中吗啡含量不确定度的数学模型,确定不确定度来源及分量,选择合理的评定方法,计算出检测结果的合成标准不确定度和扩展不确定度。结果当体液中吗啡含量为224.3 ng/m L时,其扩展不确定度为5.4 ng/m L,k=2。其中,测量重复性对不确定度的影响最大。结论采用液相色谱-质谱联用法测定体液中吗啡的含量应严格控制实验条件,要多人多次重复测量。

Objective To evaluate the measurement uncertainty for the determination of morphine content in body fluids because of its great significance in the field of forensic toxicology. Methods A mathematical model of uncertainty evaluation was designed for the determination results of morphine in body fluids performed with liquid chromatography-tandem mass spectrometry. The various sources and quantity of uncertainty were determined by the established mathematical model. A reasonable evaluation method was selected to calculate the combined standard uncertainty and expanded uncertainty. Results The expanded uncertainty of 5.4 ng/M1 （k=2） was derived with 224.3 ng/mL of morphine. The repeatability of detection was regarded as the major source of uncertainty of measurement. Conclusions It is necessary and important to control experimental conditions strictly and perform repeated measurements by different people to ensure the accuracy of the testing results.