| The method of sorbent tube and two-stage thermal desorption and GC/MS was used for analyzing volatile halocarbons with strict quality assurance and quality control in this paper. Eleven selected halocanrbons including CFCs, lower halocarbons, chlorobenzenes were measured in order to analyze their concentration and spatio-temporal distribution. The studies were performed on halocarbon profiles emitted from 8 kinds of typical sources, including natural sources (ocean and orchard), industrial sources (sponge production, ethylene petrochemical industry and municipal solid waste incineration), domestic sources (dry cleaning and old air-conditioner), urban traffic sources (on-road). Using two kinds of source apportionnment models, the concentration contribution of volatile halocarbons in Guangzhou area were calculated. The results were showed as following.(1)The detectable volatile halocarbons included CFC-11, CFC-113, CH3Cl, CH2Cl2, CHCl3, C2H4Cl2, C2HCl3, C2Cl4, C6H5Cl, o-dichlorobenzene and p-dichlorobenzene. Compared to some other cities in the world, mean concentration levels (11.48μg/m3-20.12(μg/m3) of the eleven halocarbons in Guangzhou were higher.(2)Volatile halocarbons had obvious spatial distribution. From north to south along the routine of Conghua-Urban Guangzhou-Wanqingsha, the concentration of CFC-11 and CFC-113 was distributed in Urban Guangzhou>Conghua>Wanqingsha, and the spacial distribution of the other halocarbons except CH3Cl was Urban Guangzhou> Wanqingsha> Conghua.(3)Different kinds of halocarbons had different diurnal variations. CFCs in all the sampling sites had no diurnal variation. Concentration peaks of low halocarbonds appeared in the noon time 12:00pm and in the evening time 18:00pm. Concentration peaks of chlorobenzenes appeared in 12:00-13:00pm.(4)Various halocarbons source emissions had significantly different characteristics. Natural source which was dominated by marine and orchard released high level of methyl chloride. Sponge plant with unusually high concentrations of methylene chloride reached 1000μg/m3 in discharge and workshops. Chlorobenzenes and lower halocarbons were main pollutants in production processes of Ethylene Petrochemical. Dry cleaners got a highest concentration of PCE. The concent of CFC-11 from old air-conditioner was the highest. The most abundant species were dichloromethane, dichloroethane and vinyl chloride in traffic source.(5) Receptor models were used to calculate the contribution of pollution sources. The pricipal component analysis (PCA) results showed that industrial sources which use organic solvents contributed 27.62% to the ambient halocarbons, and then natural sources with marine, orcharde-waste clean industry sources and traffic source contributed 18.95%,13.82% and 9.57% respectively. The CMB results indicated that ocean (34.2%)> sponge production (28.7%)> ethylene petrochemical industry (15.3%)> municipal solid waste incineration (9.8%)> urban road traffic (5.6%)> orchard (5.4%)> unknown source (1.7%)> old air-conditioner (0.6%)> dry cleaning (0%).
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