ICP-MS结合微区XRF法分析海带中无机元素含量及分布

为评价海带中无机元素组成及其分布特征,采用电感耦合等离子体质谱法(ICP-MS)对我国不同产地海带中无机元素进行分析,采用高效液相色谱串联ICP-MS(HPLC-ICP-MS)对海带中的不同砷形态进行定量分析,应用微区X射线荧光法(Micro-XRF)分别测定海带中无机元素的微区分布。ICP-MS分析结果显示,海带中无机元素含量丰富,以锰(Mn)、铁(Fe)、锶(Sr)、铝(Al)含量较高,重金属砷(As)、铬(Cr)元素超出食用国家标准限量要求。HPLC-ICP-MS分析结果显示海带含有的As元素以毒性较小的砷甜菜碱(AsB)为主,毒性较强的无机砷占比较低,但仍超出食用国家标准限量的1~4倍。微区XRF分析结果显示,元素As、铅(Pb)、Fe、铜(Cu)、Mn、镍(Ni)主要分布于海带外表皮,其中As和Pb有明显由表皮向内部扩散的趋势。研究结果可为海带的产地加工处理及药用和食用安全提供重要依据。

Content and distribution of inorganic elements in Laminaria japonica based on ICP-MS and Micro-XRF

In order to evaluate the composition and distribution characteristics of inorganic elements in Laminaria japonica,this study employed inductively coupled plasma mass spectrometry(ICP-MS)to detect the inorganic elements and used high performance liquid chromatography tandem ICP-MS(HPLC-ICP-MS)to determine the content of different arsenic species in L.japonica from diffe-rent origins.Micro X-ray fluorescence(Micro-XRF)was used to determine micro-area distribution of inorganic elements in L.japonica.The results showed that the average content of Mn,Fe,Sr,and Al was high,and that of As and Cr exceeded the limits of the national food safety standard.According to the results of HPLC-ICP-MS,arsenobetaine(AsB)was the main species of As contained in L.japonica.The more toxic inorganic arsenic accounts for a small proportion,whereas its content was 1-4 times of the limit in the national food safety standard.The results of Micro-XRF showed that As,Pb,Fe,Cu,Mn,and Ni were mainly distributed on the surface of L.japonica.Among them,As and Pb had a clear tendency to diffuse from the surface to the inside.The results of the study can provide a basis for the processing as well as the medicinal and edible safety evaluation of L.japonica.