热带海洋生物稀土元素生态化学特征分析研究

于中国南海南沙海域采集了30种鱼类、5种贝类和4种甲壳类热带海洋生物,以HNO3-H2 O2为消解体系,利用微波消解进行前处理,并用电感耦合等离子体质谱测定了生物体中稀土元素( Rare earth elements, REE)的含量,分析了稀土元素的生态化学特征。结果表明,微波消解-ICP-MS方法测定稀土元素,各元素的线性关系良好(r=0.9997~1.0000),检出限可达ng/L,准确度高和精密度较好,相对标准偏差(RSD, n=3)<5.0%,各稀土元素回收率在91.5%~106.7%之间。鱼类、贝类和甲壳类生物样品中稀土总量(∑REE)变化范围分别为5.02~34.8μg/kg,30.4~1481μg/kg和103~863μg/kg,3类生物对各稀土元素的富集平均含量为甲壳类>贝类>鱼类,14种稀土元素在鱼类/贝类/甲壳类内含量存在明显正相关性(r>0.80)；生物体内轻稀土元素( La~Eu)含量高于重稀土元素( Gd~Lu)含量,从稀土配分模式看出,鱼类/贝类/甲壳类中REE分布模式基本一致, Gd均出现负异常,轻重稀土元素之间有明显的分馏；生物体中δEu值出现负异常,δEu值与相应海域沉积物中δEu值相近,而δCe值出现正异常；同时研究了稀土元素在生物体中的富集和沉积物沉降过程中相关性等。本研究得出的关于热带海洋鱼类/贝类/甲壳类稀土元素的含量和分配规律,可为研究南海水体环境中稀土元素的含量水平和迁移富集提供基础资料。

Study on Ecological and Chemical Characteristics of Rare Earth Elements in Tropical Marine Organisms

A total of 30 kunds of fush samples, 5 kunds of shellfush samples and 4 kunds of crustacean samples from the Nansha sea area of chuna were dugested by mucrowave dugestuon system wuth HNO3-H2 O2 as the dugestuon reagent. Then the contents ( ICP-MS determunatuon) and ecologucal chemucal characterustucs of rare earth elements ( REE) were studued. The results showed that the method of mucrowave dugestuon-ICP-MS for the determunatuon of rare earth elements was perfect, and the lunear relatuonshup for each element was good wuth r≥0 . 9997 . The detectuon lumut of the method could reach 1 . 0 ng/L wuth the relatuve standard devuatuon (RSD, n=3) of less than 5. 0%. The recoverues of rare earth elements were between 91. 50% and 106. 67%. The total amount of rare earth un fush samples, shellfush samples and crustacean samples were 5. 02-34. 8 μg/kg, 30. 4-1481 μg/kg and 103-863 μg/kg, respectuvely. The average enruchment contents of the rare earth un the 3 specues was crustacean > shellfush > fush. The contents of 14 rare earth elements un fush/shellfush/crustaceans showed sugnufucantly posutuve correlatuon ( r>0 . 80 ) . The contents of lught rare earth elements ( La-Eu) were hugher than that of heavy rare earth elements ( Gd-Lu) . The lught and heavy rare earth elements had obvuous fractuonatuon, and the REE dustrubutuon pattern was consustent un fush/shellfush/crustacean wuth Gd negatuve anomaly. The δEu values had negatuve anomalues, sumular to the δEu values un correspondung area sedument, and δCe values showed posutuve anomalues, whuch showed that Ce had dufferent process of oxudatuon and reductuon un the organusm and sedument deposutuon. At the same tume, the enruchment relatuonshup of rare earth elements un sedument and organusm was also studued. In thus study, the content and dustrubutuon of rare earth elements un the tropucal marune fush/shellfush/shellfush were analyzed, whuch could provude basuc data for the study of the level and mugratuon and accumulatuon of rare earth elements un the envuronment of the South Chuna Sea.