甲烷中四氢噻吩气体标准物质制备及应用

Preparation and application of tetrahydrothiophene gas reference material in methane

关键词:  甲烷  四氢噻吩  标准物质  加臭剂  检测 

Key words:  methane  tetrahydrothiophene  reference material  deodorant  detection

摘要:

目的 为天然气加臭剂的测量活动提供可追溯性,以保证检测结果的准确可靠。方法 采用称量法研制了摩尔分数为1.00~20.00 μmol/mol的甲烷中四氢噻吩气体标准物质,考查了该气体标准物质的均匀性和稳定性。依据该标准物质建立了硫化学发光检测器气相色谱仪(GC-SCD)测定甲烷中四氢噻吩的方法。结果 制得的气体标准物质相对扩展不确定度为2%,k=2,国家标准物质证书编号为GBW(E)062460,采用GC-SCD测定甲烷中四氢噻吩的方法,在摩尔分数为0~5.00 μmol/mol的范围内,线性良好,相关系数r=1.000,检出限低至0.03 μmol/mol,并应用于天然气样品的测试,7次测量的相对标准偏差为2.1%~3.4%。结论 基于有证标准物质进行量值溯源的GC-SCD测定甲烷中四氢噻吩的方法准确可靠,为天然气中加臭剂四氢噻吩的测量提供技术保障。 

Abstract:

Objective The aim is to provide traceability for the measurement activities of natural gas deodorant to ensure the accuracy and reliability of the test results. Methods The reference material of tetrahydrothiophene in methane with the concentration of 1.00—20.00 μmol/mol was preparated by weighing method. The homogeneity and stability of the reference material were evaluated. The determination method of tetrahydrothiophene in methane with sulfur chemiluminescence detector gas chromatography(GC-SCD) was established based on the reference material. Results The relative extended uncertainty was 2%, k=2, and the number of the National Certified Reference Material was GBW(E)062460. The method which was developed to determine tetrahydrothiophene in methane by GC-SCD showed that it had good linearity in the range of 0-5.00 μmol/mol, a good linear relationship with the correlation coefficient r of 1.000, detection limit of the method was 0.03 μmol/mol,and the RSD was between 2.1% to 3.4% (n=7). Conclusion The method based on certified reference material by GC-SCD is accurate and reliable, which provides technical support for the measurement of tetrahydrothiophene in natural gas.