卧龙巴郎山地区夏、冬两季土壤中有机氯农药和低氯代多氯联苯的海拔高度分布

DISTRIBUTION OF ORGANOCHLORINE PESTICIDE AND POLYCHLORINATED BIPHENYLS IN SOILS WITH ALTITUDE FROM WOLONG HIGH MOUNTAIN AREA,SICHUAN PROVINCE,CHINA

利用同位素稀释质谱法测定了卧龙高海拔地区土壤中有机氯农药(OCPs)和低氯代多氯联苯(PCBs)的含量.海拔高度2800m以上,土壤中HCHs和DDTs平均含量冬季(0.517和0.556ng·g-1dw)高于夏季(0.293和0.323ng·g-1dw).夏、冬两季的土壤中PCB28和PCB52含量浓度水平相近.以土壤干重表示的OCPs和低氯代PCBs含量随海拔升高而降低,而用有机碳归一化表示的含量随海拔升高而增加,证明了在卧龙高海拔地区存在着POPs的辛醇-空气分配系数与冷凝结效应相结合的富集现象.

Concentrations of organochlorine pesticide （OCPs）and polychlorinated biphenyls （PCBs）in soils at different altitude levels of Wolong high mountain area were analyzed with HRGC-HRMS. The total average concentrations of HCHs and DDTs showed higher levels in winter soils（0. 517 and 0. 556 ng·g^-1 dw, respectively） than that in summer（0. 293 and 0. 323 ng · g^-1 dw, respectively） at stations above 2800 m. Similar concentration levels of PCB28 and PCB52 occurred in both summer and winter soils. The concentrations of all compounds expressed in dry weight of soil mass showed inverse correlations with altitude but showed positive relationship with altitude if normalized by TOC content （ng ·g^ -1 TOC ）, demonstrating the enrichment of these compounds with the altitudes controlled by the octanol-air partition coefficients of the chemicals （KoA） and the temperature effect.