[Development of standard gas mixture of 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 micromol/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.