X射线荧光光谱法测定海洋沉积物中的41种元素及氧化物  

Determination of 41 Elements and Oxides in Marine Sediments by X-ray Fluorescence Spectrometry

作　　者：孙萱[1] 宋金明[1] 温廷宇 刘瑶 SUN Xuan;SONG Jin-ming;WEN Ting-yu;LIU Yao(Institute of Oceanology,Chinese Academy of Sciences,Qingdao 266071,China)

机构地区：[1]中国科学院海洋研究所,山东青岛266071

出　　处：《海洋科学》2018年第4期79-88,共10页Marine Sciences

基　　金：中国科学院仪器设备功能开发技术创新项目(Y5KY01101L);山东省-国家基金委联合基金(U1606404);青岛国家海洋实验室深海预研专项(2016ASKJ14)~~

摘　　要：海洋沉积物样品具有盐分含量高、吸水性强、基体复杂、不同元素浓度差异悬殊等特点,其元素定量分析无论在样品前处理以及分析测试方法都有不少问题。特别是常微量元素很难用同一种方法进行测定,波长色散X射线荧光光谱可以很好的解决这一难题。因此,本文构建了粉末压片制样波长色散X射线荧光光谱法直接测定海洋沉积物样品中41种元素或其氧化物(Na_2O、MgO、Al_2O_3、SiO_2、P、S、Cl、K_2O、CaO、Fe_2O_3、Sc、Ti, V、Cr、Mn、Co、Ni、Cu、Zn、Ga、As、Br、Rb、Sr、Y、Zr、Nb、Mo、Cd、Sn、Sb、Ba、La、Hf、W、Pb、Bi、Ce、Nd、Th、U)的方法。样品在30 t的压力下保压30 s,制备的样片坚固光滑、吸潮性小。针对海洋地质样品的多样性,通过多种校准标准品拟合曲线进行测量,降低了检出限,优化了测量条件。用经验系数、理论α系数与经验系数相结合和康普顿散射线内标法校正元素间的基体效应。对土壤成分标准物质GBW07408和海洋沉积物成分标准物质GBW07315进行精密度考察,大部分元素的方法精密度提高至0.16%~3.87%,绝大多数主次痕量元素的测量精密度(RSD)小于4%,方法检出限为0.8~220μg/g。对渤海湾三个站位沉积物样品41种元素或其氧化物测定,结果表明,测定方法的重复性好,经国家一级标准物质验证,表明方法准确可靠,能满足日常分析要求。该方法对水系沉积物、土壤等陆地地化样品同样适用。A method for determining Na2O,MgO,Al2O3,SiO2,P,S,Cl,K2O,CaO,Fe2O3,Sc,Ti,V,Cr,Mn,Co,Ni,Cu,Zn,Ga,As,Br,Rb,Sr,Y,Zr,Nb,Mo,Cd,Sn,Sb,Ba,La,Hf,W,Pb,Bi,Ce,Nd,Th,and U in pressed powder pellets of marine sediment samples by X-ray fluorescence spectrometry is reported in this paper.Boric acid was admixed with the liner material,and the samples were kept under a pressure of 30 t for 30 s.The prepared samples were solid,smooth,and had a low moisture absorption.The matrix effect between elements was corrected by combining the empirical coefficient,theoreticalαcoefficient,and Compton scattering internal standard method.The detection limit of the method was 0.8~220μg/g.The precision of the soil standard substance GBW07408 and marine sediment standard substance GBW07315 were examined,and the relative standard deviation(RSD)of most elements were 0.16%~3.87%(n=12).The results show that the method was efficient in determining 41 elements or their oxides in three sediments of Bohai Bay,and it has a good reproducibility.The method is equally applicable to land-based sediments.

关 键 词：波长色散X射线荧光光谱法 粉末压片制样 主次痕量元素 基体效应 海洋沉积物 

分 类 号：P736.4[天文地球—海洋地质]