A Preliminary Approach to Mimic the Formation of POPs in the Atmosphere：Chlorination of Benzene in the Gas Phase

Abstract

The process of persistent organic pollutants( POPs) formation was studied by using the collision chamber of tandem mass spectrometer instead of atmospheric environment. It is found that chlorobenzenes can be formed through gas phase ion-molecule reaction in the collision chamber. And the formation of chlorobenzenes in the ion source of the mass spectrometer is also observed. When benzene content is 4 × 10 -3 Pa and acetyl chloride content is 4 × 10 -4 Pa,the chlorobenzene content reaches 5 × 10 -8 Pa,while the background of chlorobenzene is only 5 × 10 -9 Pa. So it is possible that the formation of chlorobenzene by gas phase ion-molecule reactions,because chlorobenzene is formed easier in atmosphere than that in the collision chamber.