目的 建立电感耦合等离子体质谱法(ICP-MS)测定环境空气PM2.5中铅浓度的测量不确定度评定方法。方法 依据HJ657-2013《空气和废气 颗粒物中铅等金属元素的测定 电感耦合等离子体质谱法》测定环境空气PM2.5中铅的浓度，建立数学模型，分析不确定度来源，计算各个不确定度分量并合成标准不确定度，最后获得扩展不确定度。结果 环境空气PM2.5中铅的扩展不确定度为0.16 ng/m3，铅的测量结果为（1.75±0.16）ng/m3。结论 方法的不确定度主要来源于样品前处理引入的相对标准不确定度。
Objective To establish an evaluation method of uncertainty for the determination of lead in ambient air PM2.5 by inductively coupled plasma mass spectrometry (ICP-MS). Methods According to HJ657-2013 "Determination of Lead and Other Metal Elements in Air and Exhaust Particulates by Inductively Coupled Plasma Mass Spectrometry", the concentration of lead in ambient air PM2.5 was determined. A mathematical model was established to analyze the source of uncertainty and to calculate each component of uncertainty. The components were combined into the standard uncertainty, and the relative expanded uncertainty was finally obtained. Results The expanded uncertainty of lead in ambient air PM2.5 was 0.16 ng/m3, and the measurement result of lead was (1.75±0.16)ng/m3. Conclusion The main source of uncertainty of this method comes from the relative standard uncertainty introduced by sample pretreatment.