通过建立 HPLC 法测定粮谷中赭曲霉毒素 A（OTA）含量的不确定度评定方法，计算测定过程中各分量的标准不确定度和扩展不确定度，对测定结果的不确定度来源及相对贡献进行比较与评定．结果表明：测定结果的不确定度来源于校准不确定度、样品称量不确定度和体积不确定度、前处理过程样品回收率（Rec）不确定度和仪器测定过程中的不确定度，其中，校准不确定度中标准溶液配制不确定度的相对贡献最多，体积不确定度最小；当粮谷中 OTA 的含量为3．17μg／kg 时，其扩展不确定度为0．476μg／kg（包含因子 k ＝2）．因此，检测人员应严格按照规范配制标准溶液，同时把握好前处理过程中提取、净化、洗脱等步骤的关键控制点，从而将测定结果的不确定度控制在可接受的范围内．
Uncertainty evaluation in the determination result of ochratoxin A in cereal grains by HPLC
An evaluation method for uncertainty in measuring ochratoxin A(OTA)in cereal grains with HPLC was established.Standard uncertainty and expanded uncertainty of the components in the process of the determination were calculated,an evaluation and comparison on the sources of uncertainty and the rela-tive contribution were made.The results showed that the sources of the determination result uncertainty could be attributed to uncertainty of calibration,weighting sample,volume,recovery and testing by instru-ment.Preparing standard solution of the uncertainty of calibration accounted for the largest proportion of the uncertainty,and the uncertainty of volume accounted for the minimum.The expanded uncertainty was 0.476 μg/kg (coverage factor k =2)when the content of OTA was 3.17 μg/kg in cereal grains.There-fore,testing personnel should prepare standard solution strictly in accordance with the specification,at the same time,hold good critical control points of pretreatment process steps such as extraction,purification, elution and so on,in order to control the uncertainty of the determination results in an acceptable range.
国家科技期刊平台
NSTL
万方数据
维普
