氮中丙烯腈气体标准物质的研制

以高纯丙烯腈和高纯氮气为原料,采用称量法配制氮中丙烯腈气体标准物质。对配制的气体标准物质分别进行机械混匀试验、压力均匀性和时间稳定性试验。经F检验,2.00μmol/mol及5.00μmol/mol两种浓度的样品在0.5~10 MPa范围内标准值无显著变化,具有较好的压力均匀性;在–20℃和40℃条件下保存7 d,其量值无显著变化,可满足运输环节量值稳定;在常温下贮存9个月量值无显著变化,表明其稳定性良好,满足国家二级标准物质对有效期的要求。对定值结果的不确定度进行评定。配制的氮中丙烯腈气体标准物质标准值为(2~5)×10~(–6)mol/mol,相对扩展不确定度为9%(k=2)。该标准物质达到国家二级标准物质的相关技术要求,可用于对丙烯腈气体报警器的校准。

Preparation of Reference Material of Acrylonitrile in Nitrogen

The reference material of acrylonitrile in nitrogen was prepared by gravimetric method with high purity acrylonitrile and nitrogen as raw material. The mechanical homogeneity test,pressure uniformity and stability test were carried out by using gas chromatography. TheFtest results showed that the reference value of 2.00μmol/mol and 5.00μmol/mol samples exhibited good uniformity with the change of the pressure from 0.5 MPa to 10 MPa,and that exhibited good stability after being stored for 9 months at room temperature and after being stored for 7 days at -20℃and 40℃,respectively. It could satisfy the requirements of transport and long-term stability of two grade reference material. The uncertainty of certified value was evaluated. The standard value of the reference material of acrylonitrile in nitrogen was (2-5)×10-6 mol/mol with the relative expanded uncertainty of 9%(k=2). The reference material meets the technical requirements of the national reference material,and can be used for the calibration of the acrylonitrile gas alarm.