高效液相色谱-串联质谱法测定甘草中赭曲霉毒素A的不确定度评定

Uncertainty evaluation for the determination of ochratoxin A in licorice by high performance liquid chromatography-tandem mass spectrometry

目的评定高效液相色谱-串联质谱法(high performance liquid chromatography-tandem mass spectrometry,HPLC-MS/MS)测定甘草中赭曲霉毒素A(ochratoxin A,OTA)的不确定度。方法采用HPLC-MS/MS法,以13C-稳定同位素标记的OTA为内标,测定甘草中OTA含量;建立数学模型,对测量重复性、标准曲线、样品前处理等不确定度来源进行分析和评定,得出合成标准不确定度和扩展不确定度。结果当甘草中OTA的含量为7.59μg/kg时,其扩展不确定度为0.50μg/kg(k=2)。结论该方法测定甘草中OTA含量的不确定度总体较小,测量不确定度的主要来源为标准曲线拟合,其次为测量重复性和标准曲线溶液配制,需要在实际操作过程中进行注意。

Objective To evaluate the uncertainty for the determination of ochratoxin A(OTA)by high performance liquid chromatography-tandem mass spectrometry(HPLC–MS/MS).Methods The concentration of OTA in licorice was determined by HPLC-MS/MS,using 13C-stable isotope labeled OTA as internal standard.Mathematical model was established to analyze and evaluate the sources of uncertainty such as measurement repeatability,standard curve,sample pretreatment,and the combined standard uncertainty and expanded uncertainty were determined.Results When the concentration of OTA in licorice was 7.59μg/kg,its expanded uncertainty was 0.50μg/kg(k=2).Conclusion The overall uncertainty of the method is low,and the main source of uncertainty results is from standard curve fitting,followed by measurement repeatability and standard curve solution preparation,which needs to be paid attention to in the actual operation process.