空气PM2.5颗粒物中铵测定的不确定度分析  

Analysis on determination uncertainy of cation NH_4^+ in the sample of air PM2.5

作　　者：孟庆玉[1] 王龑[1] 李志岭[1] 

机构地区：[1]郑州市疾病预防控制中心,河南郑州450007

出　　处：《河南预防医学杂志》2016年第11期807-811,共5页Henan Journal of Preventive Medicine

摘　　要：目的通过对空气雾霾PM2.5中阳离子NH_4^+定的不确定度评定,以期找出影响测定结果不确定度的因素,为得出准确结果、科学评价区域大气污染状况及污染物来源提供参考。方法参照《空气污染对人群健康影响监测工作手册(2015)》和《JJF1059.1-2012测量不确定度评定与表示》以及改进的样品处理方法,分析、计算了从样品采集到样品处理和离子色谱法测定NH_4^+过程中引入的不确定度。结果模拟空气PM2.5样品中NH_4^+测定的扩展不确定度为2.28μg/gm^3,样品采集、样品溶液中NH_4^+的浓度测定是分析测量不确定度的主要因素。结论在实际工作中应做好采样仪器的定期检定和适时校准,进一步改进采样方法;样品处理使用滤膜切分器、50mL大口径离心管可以提高处理速度,降低空气中暴露时间,得到满意的回收率;溶液测定中按规范做好标准溶液的配制和曲线拟合,以保证测量结果准确、可靠。Objective The article can provide reference for determining the concentration of cation NH4^＋ in the sample of air PM2.5 accurately,finding the factors that affecting analysis uncertainy and evaluating the area pollution situation and pollution source of haze formation through assessing the determination uncertainy.Methods According to the Monitoring Manual of Effects of Population Health by Air Pollution（published by 2015） and the JJF1059.1-2012 Evaluation and Expression of Uncertainy in Measurement,the authors analyzed and calculated almost all the procedure uncertainies from the sample collecting to sample treating and to detecting solution concentration by Ion Chromatography.Results The results showed that the extension uncertainy was 2.28μg/m^3 of the modified air PM2.5.The uncertainy brought by sample collecting was the first factor,the second was NH4^＋ concentration detecting of solution including standard curve plotting and fitting.Conclusions It is suggested that PM2.5 collecting instrumens should be calibrated before collecting air PM2.5.Using filter average cutter and 50 mL centigrating tube with more wide diameter can improve speed,reduce the exposure time in air and accept satisfied recoveries.It is also important to dilute standard solution and make curve correctly to get accurate and scientific results.

关 键 词：PM2.5 铵 测定 不确定度分析 

分 类 号：O659.2[理学—分析化学]