Abstract: A qualitative and speciation analysis method for organic chlorides was developed basing on comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry, and the method was applied to investigate the molecular form and distribution of organic chlorides in different atmospheric distillates from high-chlorine crude oils. Analysis results showed that organic chlorides in atmospheric petroleum distillates were mainly in forms of (poly-) chloral alkane/olefin, chlorophenol, alkylchlorobenzene, alkylchloroaniline, alkylchloronitrobenzene and their homologues. Moreover, the origin of organic chlorides in crude oil was reviewed and comprehensively analyzed, and some routes for chlorine source were inspected preliminarily by the above-mentioned GC×GC-TOF MS method. The results indicated that in the oilfield viscosity reducer there were lots of organic chlorides such as (poly-) chloral alkane/olefin, chlorhydrin, chlorinated ketone and ether, and organic chlorides in the chosen organic coatings were mainly 1,2,3-trichloropropane and polychloroethers. Consequently, molecular characterization of organic chlorides in petroleum can provide information to trace chlorine sources for developing selective chlorine removal processes, such as adsorption dechlorination, hydrodechlorination, and for designing chlorine adsorbents, chlorine transfer agents and hydrodechlorination catalysts.

Key words: organic chlorine spaciation, molecular characterization, comprehensive two-dimensional gas chromatography, time-of-flight mass spectrometry