低温浓缩-气质联用分析污染源废气中环氧氯丙烷

Determination of Epichlorohydrin Emissions from Stationary Sources Using Cryogenic Preconcentration Followed by GC/MS

建立了气袋采样-液氮低温浓缩-气质联用分析污染源废气中环氧氯丙烷的方法,优化了相关监测参数。优化后的方法在环氧氯丙烷质量浓度10~500μg/m^3范围内线性良好,相关系数>0.999,加标回收率为72.1%~85.7%,相对标准偏差<5%,气体进样量为5.0 mL时,检出限为4.37μg/m^3,可以满足废气中环氧氯丙烷监测的要求。

A method based on cryogenic pre-concentration followed by GC/MS was established for the determination of epichloro- hydrin emissions from stationary sources. A cryogenic pre-concentrator, which acts as autosampler, was used to concentrate epichlo- rohydrin collected in gas bags. Relevant parameters for cryogenic pre-concentration were optimized. After pre-concentrated, epichlo- rohydrin was introduced into GC/MS to undergo qualitative and quantitative analysis, and appraisal of the whole method was then carried out from different respects. Good linearity was obtained within 10 ~ 500 txg/m3 , and the correlation coefficient was greater than 0. 999. The average recoveries ranged from 72.1% -85.7%. Meanwhile, the method was stable enough to realize extensive use with RSD lower than 5%. The detection limit was 4.37μg/m3 based on an injection volume of 5 mL, which was sensitive e- nough to realize waste gas monitoring.