CAJ | 학술논문

采用高分辨率气相色谱-高分辨率质谱联用法分析位于青藏高原东缘的若尔盖高原牧场地表水和大气湿沉降中有机氯农药(OCPs)和多氯联苯(PCBs)异构体含量的季节分布特征,探讨持久性有机污染物(POPs)在边远清洁地区的地球化学行为.结果表明,若尔盖地区地表水中∑HCHs、∑DDTs、HCB、∑6PCBs平均浓度分别为0.90,1.36,0.95,1.35ng/L.大气降水中OCPs和PCBs平均浓度分别为0.363,0.118ng/L,最大值出现在11月初冬的降雪样品中.异构体按平均浓度排序为HCB > PCB28>p,p’-DDD >p,p’-DDE >α-HCH >γ-HCH.PCBs以PCB28和PCB52为主,除少量的PCB101外,其余高氯代PCB化合物都未在沉降样品中检出.∑HCHs、∑DDTs、∑PCBs的大气沉降通量分别为0.058~0.268,0.087~0.311,0.049~0.188ng/(m2·d).高海拔地区POPs大气沉降模式可分为“海拔梯度降水型”和“高原型”2类.类似于极地冷凝作用,高原型降雪中的POPs的沉积通量高于降雨沉降通量,但持久性较强的PCB138、PCB153和PCB180则缺失.这一结果验证了高空大气远程迁移和局地的高山冷凝效应的区别.
채용고분변솔기상색보-고분변솔질보련용법분석위우청장고원동연적약이개고원목장지표수화대기습침강중유궤록농약(OCPs)화다록련분(PCBs)이구체함량적계절분포특정,탐토지구성유궤오염물(POPs)재변원청길지구적지구화학행위.결과표명,약이개지구지표수중∑HCHs、∑DDTs、HCB、∑6PCBs평균농도분별위0.90,1.36,0.95,1.35ng/L.대기강수중OCPs화PCBs평균농도분별위0.363,0.118ng/L,최대치출현재11월초동적강설양품중.이구체안평균농도배서위HCB > PCB28>p,p’-DDD >p,p’-DDE >α-HCH >γ-HCH.PCBs이PCB28화PCB52위주,제소량적PCB101외,기여고록대PCB화합물도미재침강양품중검출.∑HCHs、∑DDTs、∑PCBs적대기침강통량분별위0.058~0.268,0.087~0.311,0.049~0.188ng/(m2·d).고해발지구POPs대기침강모식가분위“해발제도강수형”화“고원형”2류.유사우겁지냉응작용,고원형강설중적POPs적침적통량고우강우침강통량,단지구성교강적PCB138、PCB153화PCB180칙결실.저일결과험증료고공대기원정천이화국지적고산냉응효응적구별.
To further understand the geochemical behaviors of persistent organic pollutant (POPs) in remote areas, the seasonal distribution characteristics of anthropogenic organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) concentrations in surface water and wet precipitation samples collected from Zoige alpine wetland in the eastern edge of the Qinghai-Tibet Plateau were determined by HRGC-HRMS. The mean concentrations of ∑HCHs, ∑DDTs, HCB, ∑6PCBs in the surface water were 0.90, 1.36, 0.95, 1.35ng/L, respectively. The mean concentrations of ∑OCPs and ∑6PCBs in wet precipitation were 0.363, 0.118ng/L, respectively, with the maximum values present in snow of November. The mean concentrations were in the order of HCB > PCB28 >p,p’-DDD >p,p’-DDE >α-HCH >γ-HCH. PCB28and PCB52were the predominant PCB congeners. Except for trace amount of PCB101, all highly chlorinated PCB congeners were not detected. The deposition fluxes of ∑HCHs, ∑DDTs, and ∑6PCBs were in the range of 0.058~0.268, 0.087~0.311, and 0.049~0.188ng/(m2·d), respectively. The results confirmed the difference between long-range atmospheric transport via high altitude air mass and the mountain cold trapping effect. The precipitation mode of POPs in high altitude areas can be distinguished as two types, i.e., the “altitudinal gradient wet precipitation mode” and the “high plateau mode”. Similar to the cases in polar areas, the snow deposition flux of POPs in “high plateau mode” is generally higher than rain deposition flux, lack of less persistent PCB 138, PCB153and PCB180components.