电感耦合等离子体质谱法测定葡萄中铅含量的不确定度评估

摘要

建立对电感耦合等离子体质谱法(inductively coupled plasma mass spectrometer,ICP-MS)测定葡萄中铅的测量不确定度评估方法.葡萄样品经过微波消解之后,稀释,然后用ICP-MS检测其铅含量,外标法定量,根据建立的数学模型,估算各不确定度分量大小,确定对总不确定度的主要影响因素.试验结果表明置信概率为95 %,取包含因子k=2,ICP-MS法测定葡萄中铅含量结果报告为X=(16.80±1.00)μg/kg;铅含量测量不确定度的主要因素是由回收率产生不确定度和铅溶液浓度所产生的不确定度.%The uncertainty of plumbum in Grapes was assessed,a mathematical model for each component was established and the uncertainty components was estimated.The results showed the report of uncertainty of Pb in grape as X=(16.80±0.80)μg/kg with a confidence probability of 95 % and the coverage factor k=2.The major factor that affected the uncertainty came from the uncertainty of the variation of cucontent caused by recovery, and one of main cause affected the uncertainty was caused by the uncertainty of dilution in the process of standard curve preparation.