中文摘要：

针对赣南稀土矿区脐橙果园土壤及脐橙,研究表层土壤及土壤中稀土元素的赋存形态,并测定脐橙中稀土元素的含量。土壤样品经HNO3-HF-HClO4酸体系预消解后再经微波消解,然后用电感耦合等离子体质谱（ICP-MS）测定其中15种稀土元素含量。为进一步研究土壤中稀土元素的赋存形态,土壤样品经连续提取法（BCR）提取后测定稀土元素的形态特征。结果表明,矿区果园表层土壤中稀土元素总量高于非矿区土壤的稀土元素含量,也高于我国土壤稀土元素含量的平均值,且矿区果园土壤的稀土属典型的富含重稀土元素的离子吸附矿型;矿区果园土壤中可氧化态和可还原态稀土元素含量占总含量百分比分别为61.6%和31.9%,而酸溶态和残渣态稀土元素含量占总含量百分比则仅为4.4%和1.98%,表明矿区果园土壤中稀土元素相对稳定,生物活性不高。实验测得矿区果园产的脐橙果肉中稀土元素含量为0.215mg/kg,远低于2005年颁布的食品污染物限量标准（GB2762—2005）中规定的水果类稀土氧化物限量值（≤0.7mg/kg）,表明矿区果园脐橙中稀土元素含量对人体无害。

英文摘要：

In order to investigate speciation of rare-earth elements（REEs） in soils,contents of REEs in surface of soils and navel oranges collected from rare-earth mining area in southern Jiangxi,China,were determined.Soil samples were sequentially digested with HNO3-HF-HClO4 and microwave oven.Contents of fifteen REEs in samples were determined with inductively coupled plasma mass spectrometry（ICP-MS）.The characterization of REEs in soils was further investigated to identify speciation.Results indicated that contents of REEs in orange-growing soils around rare-earth mining area were obviously higher than those in soils far away rare-earth mining area.An ion-adsorption type ore enriched in heavy REEs was observed in orange-growing soils around mining area.Large amount of REEs in orange-growing soils were in oxidative and reducible states,which reached 61.6% and 31.9% of total amount,respectively.While contents of REEs in soils existed as acid-soluble and residual states were 4.4% and 1.98%,respectively,suggesting that REEs in orange-growing soils around rare-earth mining area were relatively stable and exhibited a lower bioavailability.The total content of REEs in navel oranges grown in soils around mining area was 0.215 mg/kg,and much lower than the maximum limit level（≤0.7 mg/kg） of contaminants in foods issued in China（GB 2762— 2005）.All of these investigations also provided the information that navel orange grown in soils around rare-earth mining area had no harmful to human health.