Analytical method for hexachlorobutadiene in chemical manufacturing samples by gas chromatography-mass spectrometrometry
Hexachlorobutadiene(HCBD)has been listed in Stockholm Convention in 2017,as a kind of emerging persistent organic pollutants(POPs).Chemical manufacturing processes such as chlor-alkali production can unintentionally produce HCBD as byproducts,which is considered as the main source of HCBD at present.Current HCBD related studies mainly focused on environmental samples such as soil and atmosphere surrounding chemical production plants.However,few studies has been conducted on HCBD occurrences in chemical products or chemical residues during the chemical manufacturing processes.This study established a gas chromatography-mass spectrometry(GC-MS)method for the analysis of HCBD in chemical manufacturing samples such as chloroethylene and chlorobenzene.The chromatographic parameters containing inlet temperature,heating procedure and carrier gas flow rate were optimized.The linear range of the standard curve is 0-500 ng·mL-1.The recoveries of the method were 77.8%-102%,and the relative standard deviations were 3.6%-6.0%.The correlation coefficient R2 of the standard curve was 0.9998.The detection limit was 0.049 ng mL-1,and the limit of quantification was 0.16 ng·mL-1,which could meet the accurate qualitative and quantitative requirements of HCBD in chemical samples.The established GC-MS analysis method was then applied to the analysis of HCBD in practical chemical samples from typical chloroethylene and chlorobenzene manufacturing processes in China.It was found that the concentration of HCBD in the production of trichloroethylene and tetrachloroethylene(0.003-243000 μg·mL-1)was much higher than that of chlorobenzene.The method can provide technical support for the study of HCBD emission in the chemical production process,and provide important information for their source identification and emission control.