电感耦合等离子体质谱法测定食用植物油中铅、总砷含量不确定度评定

采用电感耦合等离子体质谱法(ICP-MS)测定食用植物油中铅(Pb)、总砷(As)含量,对测定结果的不确定度进行评定。利用ICP-MS,采用标准加入法测定食用植物油中Pb,As含量,分析测定过程中不确定度来源,包括样品称量、定容、前处理、溶液中Pb和As浓度、重复性测量等引入的不确定度,计算合成不确定度。结果表明,Pb含量为(0.0228±0.013) mg/kg,k=2;As含量为(0.00785±0.0045) mg/kg,k=2。该方法的不确定度主要来源于样品溶液中的Pb,As浓度,评定得到的不确定度可为正确评价测定结果提供科学依据。

Uncertainty evaluation in determination of lead and arsenic in edible vegetable oil by inductively coupled plasma mass spectrometry

The content of lead (Pb) and arsenic (As) in edible vegetable oil was determined by inductively coupled plasma mass spectrometry (ICP-MS).The uncertainty of the determination results was evaluated.The content of Pb and As in edible vegetable oil was determined by ICP-MS using standard addition method,The sources of uncertainty in the determination process were analyzed,including the uncertainty introduced by sample weighing,constant volume,pretreatment,concentration of Pb and As in solution,repeatability measurement,etc.the synthetic uncertainty was calculated.The results showed that the Pb content was (0.0228±0.013) mg/kg,k=2,and the As content was (0.00785±0.0045) mg/kg,k=2.The uncertainty of the method is mainly the concentration of Pb and As in the sample solution.The uncertainty obtained by the evaluation can provide a scientific basis for the correct evaluation of the measurement results.