X射线荧光光谱法测定锡矿石中锡

本文采用向样品中加入硼酸来降低基体效应，加入氧化镧来稳定样品总质量吸收系数，建立固体粉末压片制样-X射线荧光光谱法测定锡矿石中锡含量的方法。通过将标准物质按一定比例混合配制和选取部分自制标样来补充标准物质样品，以解决锡矿石标准物质样品缺乏的问题。实验优化了稀释比，确定了以最佳稀释比为m（矿物质样品）:m（硼酸）：m（氧化镧）=1.0:2.0:0.5。在最优的实验条件下，Sn的荧光强度（kcps）与Sn浓度CSn呈良好的线性关系，R2=0.9989。方法中锡元素的最低检出限为0.005 %，测定范围在0.015 %-4.47 %之间。样品的混合均匀性实验表明各元素测定结果的相对标准偏差（RSD,n=6）在1.0 %-2.64 %之间。对3个不同含量段的物质进行测定来验证方法的准确度和精密度，准确度分别为0.0082-0.0367，均小于0.04，精密度分别为0.39 %-1.18 %，均小于8.0 %，准确度和精密度均符合地质样品分析规范要求。测定值均在误差范围内，各组分测定结果的相对标准偏差（RSD,n=11）在1.20 %以下。粉末压片-X射线荧光光谱法测定锡矿石中锡含量具有分析范围广、分析时间短、重现性好、精度高且操作简单等特点。能应用于地质、环境、材料等领域。

Determination of tin content in tin ore by X-ray fluorescence spectrometry

In this paper, boric acid was added to the sample to reduce the matrix effect, and lanthanum oxide was added to stabilize the total mass absorption coefficient. On this basis, a method for the determination of tin content in tin ore by solid powder pressing sample preparation and X-ray fluorescence spectrometry was established. In order to solve the problem of the lack of tin ore reference material samples, the experiment adopts the mixing of reference materials in a certain proportion and selecting some self-made standard samples to supplement the reference material samples. The experiment optimized the dilution ratio, and determined the optimal dilution ratio as m (mineral sample) :m (boric acid) :m (lanthanum oxide) =1.0:2.0:0.5. Under the optimal experimental conditions, the fluorescence intensity (KCPS) of Sn showed a good linear relationship with the concentration of Sn (R2=0.9999). The minimum detection limit of tin in the method is 0.005%, and the detection range is between 0.015% and 4.47%. The relative standard deviations (RSDs,n=6) for the determination of the elements were between 1.0 % and 2.64 %. The accuracy and precision of the method were verified by measuring the substances in three different content sections. The accuracy was 0.0082-0.0367, all less than 0.04, and the precision was 0.3912%-1.1804%, all less than 8.0%, respectively. The accuracy and precision were in line with the requirements of the geological sample analysis specification. The measured values were within the error range, and the relative standard deviation (RSD,n=11) of each component was less than 1.20%. The determination of tin content in tin ore by powder tablet - X-ray fluorescence spectrometry has the characteristics of wide analysis range, short analysis time, good reproducibility, high accuracy and simple operation. It can be used in geology, environment, materials and other fields.