中文摘要：

用连续提取法对选自西北冰洋的32个表层沉积物进行分析,测定了Cr、Cu、Pb在全样中及其在P1-2、P3、P4、P5中的含量.结果表明随着离岸距离增加,水深加深,Cr、Cu、Pb含量呈增高的趋势.研究区陆架沉积物中Cr、Cu、Pb含量分别为60.66、14.77、16.65μg/g;深海沉积物中Cr、Cu、Pb的含量分别为80.40、41.70、25.62μg/g.元素赋存形态分析表明,Cr、Cu、Pb主要赋存在残渣态,残渣态中三元素的含量平均值分别为64.97、19.67、17.56μg/g,占元素总量的比例分别为93.58%、75.02%和83.76%.三元素在各赋存形态中的含量分布是：Cu为残渣态〉有机质和硫化物态〉铁锰氧化态〉可交换及碳酸盐态;Pb和Cr则为残渣态〉铁锰氧化物态〉有机质硫化物态〉可交换态及碳酸盐态.研究区重金属元素在不同赋存形态中的含量分布与北太平洋深海沉积物中类似.

英文摘要：

The particular behavior of trace metals in the environment is determined by their existing states rather than by their total concentration.In order to evaluate the behavior of Cr,Cu and Pb in the western Arctic Ocean,32 surface sediments were selected from the Chukchi Sea,the Beaufort Sea,and the Canada Basin during the First and Second Chinese Arctic research expedition.The study shows that existing states of heavy metals were divided into exchangeable and carbonate form（P1-2）,Fe-Mn oxidation form（or Reducible state,P3）,organic matter and sulfide form（or Oxidizable state,P4） and residual form（or Silicate state,P5）.The Cr,Cu and Pb contents in bulk sample and four states were determined by sequential extraction method.The results demonstrate that Cr,Cu,Pb contents display an upward tendency with the increasing of both the offshore distance and the water depth.In the study area,Cr,Cu and Pb contents are 60.66,14.77,16.65 μg/g in the shelf sediments,while 80.40,41.70,25.62 μg/g in the deep-sea sediments.The analyses of element speciation show that Cr,Cu,Pb mainly exist in residual form,and the average contents of the three elements are 64.97,19.67,17.56 μg/g which account for 93.58%,75.02% and 83.76% of the total elements respectively.Meanwhile Cr,Cu and Pb content in exchangeable and carbonate form is the lowest of all.Their proportions are all lower than 3%.The distributions of the three elements in each speciation are：Cu in residual form（75.02%） organic matter and sulfide form（14.16%） Fe-Mn oxidation form（10%） exchangeable and carbonate form（0.82%）;Pb and Cr in residual form（Pb：83.76%;Cr：93.58%） Fe-Mn oxidation form（Pb：12.24%;Cr：3.65%） organic matter and sulfide form（Pb：3.61%;Cr：2.67%） exchangeable and carbonate form（Pb：2.73%;Cr：0.1%）.Speciation distribution of heavy metals in the study area is very similar to that in the deep-sea sediments in the North Pacific.