气相色谱-质谱法测定奶粉中香兰素的不确定度评估

目的采用气相色谱-质谱法对奶粉中香兰素含量的不确定度评估。方法建立不确定度评估的数学模型,通过对不确定度的各主要分量进行分析计算,得出合成不确定度以及扩展不确定度。结果当香兰素的测定结果为57.1 mg/kg时,其扩展不确定度为4.4 mg/kg,k=2。结论采用气相色谱-质谱法测定奶粉中香兰素含量,其不确定度的主要来源为样品的回收率和最小二乘法拟合的标准曲线,该评估模型为检测奶粉中香兰素的不确定度评估提供了参考依据。

Evaluation of uncertainty in determination of vanillin in milk powder by gas chromatography-mass spectrometry

Objective To develop an uncertainty evaluation method of vanillin in milk powder by gas chromatography-mass spectrometry (GC-MS). Methods The mathematical model of uncertainty evaluation was established after the sources of uncertainty were systematically analyzed. Through calculating the each uncertainty during analysis process, the combined and expanded uncertainties were obtained. Results When the measurement result of vanillin was 57.1 mg/kg, the expanded uncertainty was 4.4 mg/kg, k=2. Conclusion The main sources of uncertainty were caused by the recovery for samples and the establishment of standard curve with the least squares. It provides a reference basis for uncertainty evaluation of vanillin in milk powder.