粉末压片-X射线荧光光谱法测定小样品量土壤和沉积物中主量元素  

Determination of Major Elements in Small-Weight Soil and Sediment Samples by X-Ray Fluorescence Spectrometry with Pressed-Powder Pellets

作　　者：赵红坤 刘亚轩[2,3] 马生明 张艳飞[1] 张鹏鹏[2] 李强 李振清[1] 陈其慎[1] 李勇[2] 顾雪[2] 陈宏强 ZHAO Hongkun;LIU Yaxuan;MA Shengming;ZHANG Yanfei;ZHANG Pengpeng;LI Qiang;LI Zhenqing;CHEN Qishen;LI Yong;GU Xue;CHEN Hongqiang(Institute of Mineral Resources,Chinese Academy of Geological Sciences,Beijing 100037,China;Institute of Geophysical and Geochemical Exploration,Chinese Academy of Geological Sciences,Langfang 065000,China;Tianjin Agricultural University,Tianjin 300384,China;Regional Geology Survey Institute of Hebei Province,Langfang 065000,China)

机构地区：[1]中国地质科学院矿产资源研究所,北京100037 [2]中国地质科学院地球物理地球化学勘查研究所,河北廊坊065000 [3]天津农学院,天津300384 [4]河北省区域地质调查院,河北廊坊065000

出　　处：《岩矿测试》2025年第2期305-315,共11页Rock and Mineral Analysis

基　　金：中国地质调查局地质调查项目(DD20230040,DD20242247);国家重点研发计划项目(2018YFE0208300,2021YFC2903001);河北省中央引导地方科技发展资金项目(246Z4205G)。

摘　　要：实现小样品量的X射线荧光光谱(XRF)分析测试是获取珍贵和稀缺样品中化学组成过程需要解决的关键技术问题。同时,应用XRF对标准物质进行均匀性检验在最小取样量上也存在争议。在目前地质分析样品(包括标准物质)大多为74μm(-200目)粒度水平下,XRF分析压片法的常规样品量为4g左右。本文利用0.1g样品量进行粉末压片,通过更换XRF试样盒面罩直径为12mm,缩小视野光栏直径为10mm,同时在优化制样条件和仪器测量条件基础上,利用32种不同类型、不同含量梯度的地球化学标准物质,建立了0.1g样品量条件下XRF粉末直接压片法测定土壤和沉积物样品中10种主量元素(SiO_(2)、Al_(2)O_(3)、TFe_(2)O_(3)、MgO、CaO、Na_(2)O、K_(2)O、Mn、Ti和P)的分析方法,大幅度降低了样品量。0.1g样品量分析方法检出限为14μg/g~0.35%,精密度(RSD,n=12)小于3.9%。经对比分析,采用本文0.1g样品量方法分析不同含量标准物质的测定值均在标准值范围内,相对误差绝对值(|RE|)在0~15.7%,与4g样品量分析结果(|RE|在0.3%~28.3%)差异不大。采用本文方法0.1g样品量和常规方法4g样品量两种方法分析实际样品的测定结果基本吻合,验证了建立的0.1g样品量XRF分析方法可靠。The analysis of small-weight samples utilizing X-ray fluorescence spectrometry(XRF)poses a pivotal technical challenge in determining the chemical composition of valuable and scarce materials.Furthermore,the application of XRF to verify the homogeneity of reference materials has sparked debates regarding the minimum sample weight.At present,most of the geological samples(including reference material)are at the particle size of 74μm(-200 mesh)and the conventional sample weight is approximately 4g for XRF analysis with pressed-powder pellets.Here,0.1g weight soil or sediment was used for pressed-powder pellet preparation.The diameter of the XRF spectrometry sample box mask was changed to 12mm,and the diameter of the field view light barrier was reduced to 10mm.Based on the previously optimized instrumental measurement conditions,we successfully established a 0.1g sample weight analytical method for the quantification of ten major elements(SiO_(2),Al_(2)O_(3),TFe_(2)O_(3),MgO,Cao,Na_(2)O,K_(2)O,Mn,Ti,and P)utilizing wavelength dispersive XRF,which significantly reduced the necessary sample weight.This method 1employed a diverse range of 32 geochemical reference materials,encompassing variou types and content gradients.The detection limit of the 0.1g sample weight analysis method was between 14μ/g and 0.35%,and the precisioniitalic>=12)was less than 3.9%.Through comparative analysis,the results of the erence materials were all within the standard value range,and the absolute value of relative error(|RE|)was between 0 and 15.7%.There was no significant difference with the 4g sample weight analysis results(|RE|ranged from 0.3%to 28.3%).The practical sample results determined by the method of 0.1g sample and the conventional method of 4g sample are consistent.The established XRF method for the 0.1g weight sample is reliable.

关 键 词：X射线荧光光谱法 粉末压片 样品量 土壤 沉积物 

分 类 号：O657.34[理学—分析化学]