氮气中六种氯代烷烃混合标准气体的研制

介绍了氮气中6种氯代烷烃混合标准气体的制备和定值方法。标准气体的组分是二氯甲烷、三氯甲烷、1,1-二氯乙烷、1,2-二氯乙烷、1,1,1-三氯乙烷和1,1,2-三氯乙烷,标准值为5 μmol/mol。考察了标准气体的制备重现性、均匀性和稳定性。结果表明,标准气体在气瓶内均匀性良好,扩展相对不确定度为5%,使用有效期为一年。经与国外的同类标准气体比对,量值有较好的一致性。氮气中6种氯代烷烃混合标准气体的研制为挥发性氯代烷烃的检测提供了计量标准。

Development of standard gas mixture of six chlorinated hydrocarbons in nitrogen

A method for the preparation of the standard gas mixture of 6 chlorinated hydrocarbons, containing dichloromethane, 1,1-dichloroethane, 1,2-dichloroethane, chloroform, 1,1,1-trichloroethane, and 1,1,2-trichloroethane, at the concentration of 5 μmol/mol in nitrogen was developed. The reproducibility of this method and the homogeneity and long-term stability of the standard mixture were evaluated. The results showed that all 6 chlorinated hydrocarbons have shown stability as long as 12 months and the expanded relative uncertainty of 5%. The certified value of developed standard gas agreed with the similar standard gas from Scott Specialty Gases. This research established a foundation for the analysis of volatile chlorinated hydrocarbon gases.