微波消解ICP-MS法测定中华白海豚额隆中微量元素及其含量特征分析

中华白海豚是我国一级保护动物,处于海洋食物链顶端,而重金属、持久性有机污染物等污染物易在其体内富集。额隆是鲸豚回声定位的重要部位,具有传导信号的作用。为探究中华白海豚额隆中微量元素的基线水平以及其组成的主要特征成分,研究采用微波消解电感耦合等离子体质谱(ICP-MS)法测定了中华白海豚额隆中V,Ni,Cr,Mn,Cu,As,Zn,Hg,Se,Cd和Pb 11种微量元素并对其含量进行特征分析。结果表明该方法具有良好的准确度和精密度,适合于中华白海豚额隆微量元素的测定分析。样品分析显示,额隆中11种微量元素整体含量水平不高,由于个体生理状况不同,同种元素含量在不同个体中存在差异;其平均含量从高到低排序依次为:ZnAsCuMnSeHgCrNiPbVCd,其中As作为非必需有毒微量元素,含量水平较高(1.158μg·g-1 ww),可能会对海豚产生生理毒害作用。Spearman相关性分析显示,As(r=0.733),Cd(r=0.615)和Hg(r=0.645)含量与海豚体长呈显著正相关性(p0.05),表明As,Cd和Hg三种元素可随海豚年龄增加而在额隆中富集;Cs与Ni呈正相关(p0.05),Mn与As呈负相关(p0.01),表明元素间也存在着一定的关联性。此外,主成分分析结果表明,V,Mn,Ni,Se,Cu和Hg为中华白海豚额隆主要特征微量元素。研究在国内首次使用微波消解ICP-MS法对中华白海豚额隆中微量元素进行研究,结合相关性分析和主成分分析,有效探究了中华白海豚额隆中微量元素的生物富集模式与含量特征,实验结果为研究中华白海豚额隆中微量元素基线水平提供了参考。

Determination of Trace Elements in the Melon of Indo-Pacific Humpback Dolphins (Sousa chinensis)with ICP-MS

The Indo-Pacific humpback dolphins (Sousachinensis)with long life-span are top predators in marine ecosystem-and they could accumulate heavy metals and persistent organic pollutants in their tissues,while the melon is a unique lipid-rich struc-ture within the cetacean forehead that functions in the transmission of echolocation signals.To explore the baseline levels and the main characteristics of the components,the concentrations of vanadium (V),nickel (Ni),chromium (Cr),manganese (Mn), copper (Cu),arsenic (As),zinc (Zn),mercury (Hg),selenium (Se),cadmium (Cd)and lead (Pb)were determined in the melon of the Indo-Pacific humpback dolphins with inductively coupled plasma mass spectrometry (ICP-MS).The results showed that this method was quite suitable for the determination of trace elements in the melon of Indo-Pacific humpback dolphins with highly accuracy and precision,and the trace elements in melon existed individual differences.The average contents were in the order of Zn>As>Cu>Mn>Se>Hg>Cr>Ni>V>Pb>Cd.It is worth noting that the within (1.158μg·g-1 ww),non-es-sential toxic trace element may cause toxic effect on the dolphins.Spearman correlation analysis showed positively significant cor-relations between As,Cd,Hg and body length,indicating that the concentrations of As,Cd,Hg may increase with age.Moreo-ver,Cr and Ni were positively correlated (p<0.05),a significant negative correlation was observed between Mn and As (p<0.01),indicating that there are certain correlation among elements.In addition,the principal component analysis results showed that V,Mn,Ni,Se,Cu,Hg are the main characteristics of trace elements for melon.This study presents a reliable method for determination of the trace element analysis in cetacean melon,and this is the first study that reports the trance elements in the melon of the Indo-Pacific humpback dolphins in PRE that could provide reasonable and effective information for its conservation work.