| In order to investigate the mode of emission and the rule of transportation of typical persistent organic pollutants ( POPs ) , Beijing and Wolong Nature Reserve were selected as the study sites.The poplar and gingko foliages were sampled in Chinese Research Academy of Environmental Sciences in Beijing. Thirty one samplers were collected from April to November 2007. Organochlorine compounds such as HCB, HCHs, DDTs and PCBs were analysed by GC/ECD and GC/MS/MS. It was indicated that the accumulation patterns of poplar and gingko foliages for HCHs, DDTs and HCB were similar. The amount of HCHs, DDTs and HCB increased along with foliage growth in the bud burst period in April, but decreased in May, which was probably due to the foliage growth in the bud burst period, an evidence for the "bud burst effect" in plants in spring. There was no sign of recent usage of technical HCH and DDT, but there was an indication of new input of both lindane and o,p'-DDT, and the dicofol usage may be the source of o,p'-DDT. The result of this work implies that the vegetation is an important environmental medium, which participating actively in the global cycling of POPs.XAD-2 resin based passive air samplers (PAS) were used to collect atmospheric samples at different altitudinal sites in Wolong Nature Reserve. Both winter-half-year samples (October 2006-April 2007) and summer-half-year samples (April 2007-October 2007) were retrieved. Organochlorine compounds such as HCB, HCHs, DDTs and PCBs were determined using the gas chromatography-high resolution mass spectrometry ( GC-HRMS ) method. It was concluded that XAD-2 resin based PAS are applicable to long-term monitoring for POPs in air for both urban and remote areas; the POPs concentrations increased along the altitudinal gradient in Wolong, the phenomena of Cold-trapping; the POPs concentrations were higher in summer-half-year than those in winter-half-year; and atmospheric transport may be the major source of POPs in Wolong Nature Reserve. |
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