温室气体监测用4种氟氯烃混合标准气体的研制  

Development of Hydrochlorofluorocarbons Gas Standard for Determination of Greenhouse Gas

作　　者：李宁 王倩 王帅斌 倪才倩 田文 

机构地区：[1]环境保护部标准样品研究所国家环境保护污染物计量和标准样品研究重点实验室,北京100029

出　　处：《化学试剂》2016年第9期887-889,920,共4页Chemical Reagents

基　　金：环保公益性科研专项项目(201309013)

摘　　要：介绍了氮气中三氯一氟甲烷、二氯二氟甲烷、1,1,2-三氯-1,2,2-三氟乙烷、一氯三氟甲烷4种氟氯烃混合标准气体的制备方法和定值方法。考察标准气体在气瓶内壁的吸附作用、制备重现性、均匀性和稳定性。浓度水平为5-9μmol/mol的4种氟氯烃混合标准气体采用称量法制备,采用气相色谱法测定。经瓶内均匀性考察,瓶内均匀性良好。经时间稳定性考察显示,4种氟氯烃混合标准气体使用有效期为1年。标准气体的不确定度包含样品定值不确定度、瓶内不均匀性和不稳定引起的不确定度,经评估和计算,其扩展相对不确定度为3%（置信度为95%）。4种氟氯烃混合标准气体可以为温室气体环境监测提供标准技术支持。The results of the development and determination of hydrochlorofluorocarbons containing 4 compounds such as trichlo- rofluoromethane, dichlorodifluoromethane, 1 , 1 , 2-trichloro-1 , 2,2-trifluoroethanc, chlorotrifluoromethane in nitrogen gas standards are investigated. Cylinder selection, preparation method, with-in bottle homogeneity and stability researches for the gas standard mixtures were performed. Four kinds of hydrochlorofluorocarbons gas standard mixture at 5 - 9 μmol/mol was prepared by gravimetric method. This set of primary standards was intercompared to the existing gas cylinder standards using gas chromatography with a hydrogen flame ionization detector. The linear regression analysis showed excellent agreement among the standards for each compound. As a result of with-in homogeneity,the data showed that the 4 compounds were homogeneous in the cylinder. The long- term stability of the gas standard is associated with the behavior of the gas standard at the shelves of the producer. All four hydro- chlorofluorocarbons in gas cylinders have been evaluated over time and have shown stability for as long as 12 months. The uncer- tainty for the certified values of each analyte in the gas standards included uncertainty of the certified value,uncertainty of inho- mogeneity and instability. The results showed the expanded uncertainty was 3% at the 95% confidence interval per compound. This work supplied the standards support for the determination of greenhouse gas in ambient air.

关 键 词：氟氯烃 标准气体 均匀性 稳定性 不确定度 

分 类 号：O659[理学—分析化学]