车载台式能量色散X射线荧光光谱仪在地球化学勘查现场分析中的应用

On-site Geochemical Exploration Analysis by Vehicle-Loaded Energy Dispersive X-ray Fluorescence Spectrometer

充分发挥小型实验室设备的功能以提高现场快速分析的能力。在内蒙和新疆两地覆盖区的钻探现场,采用车载化台式偏振能量色散X射线荧光光谱仪,对由轻便钻采集的覆盖层和基岩样品进行了贱金属分析。共采集、制备和分析了约400件钻探样品,采用能量色散X射线荧光光谱法、波长色散X射线荧光光谱法和电感耦合等离子体质谱法对这些样品进行比对分析。现场分析数据与实验室分析数据(各方法的平均值)的比对结果表明,K、Ca、Ti、V、Cr、Mn、Fe、Ni、Cu、Zn、Ga、As、Rb、Sr、Y、Zr、Nb、Ba、Pb、Th等20余种元素的分析数据的一致性良好;含量超过10μg/g时,除了V和Ba外,其他元素的平均相对偏差均小于25%。在现场作为质控样品分析4个地质标准物质GBW07301～GBW07304,测定结果表明,除了低含量的Cu和Ga外,上述其他18种元素均符合地质行业标准地质矿产实验室测试质量管理规范(1∶20万)规定的误差要求。应用研究表明,设计的仪器车载化方案可行,现场分析方法快速、准确,适用于野外钻探、化探等急需现场数据支持的工作。

The vehicle-loaded energy dispersive X-ray fluorescence（EDXRF） spectrometry instruments were utilized for on-site analysis of superstratum and bedrock samples from light drilling at drilling fields in Inner Mongolia and Xinjiang.About 400 drilling samples were collected,prepared and analyzed on-site.The on-site EDXRF data were assessed by comparing with in-lab data obtained from the same samples by wavelength dispersive X-ray fluorescence spectrometry instruments and ICP-MS.Good consistencies were found between on-site and laboratory analysis data（the average of the various methods） for K,Ca,Ti,V,Cr,Mn,Fe,Ni,Cu,Zn,Ga,As,Rb,Sr,Y,Zr,Nb,Ba,Pb and Th.As long as concentration levels exceeded 10 μg/g,average relative deviations better than 25% were achieved for all of the above-mentioned elements except for V and Ba.Smaller relative deviations were achieved with increasing elemental concentrations.On-site analysis data of the 18 above-mentioned elements in geological reference materials GBW 07301-GBW 07304 were in good accordance with the specification of testing quality management for geological laboratories（1∶200 000）,except for Cu and Ga which were low in concentrations.The applied research results show that the vehicle-loaded instrument works properly and the on-site analysis method is rapidity,accurate and suitable for field drilling and geochemical exploration.