便携式XRF在污染地块土壤金属元素调查中的应用

研究了便携式X荧光光谱仪（PXRF）测定土壤中砷、铅、铬、铜、锌和镍的性能，评估其检出限、精密度和准确度，探索了土壤水分和粒径对测定结果的影响程度，并与常规实验室分析方法测定结果进行比对。结果表明，PXRF测定土壤中砷、铅、铬、铜、锌和镍的检出限为5~15mg/kg，标准物质测定结果的相对标准偏差（RSD）≤8.6%，相对误差在±15%以内。随着土壤水分含量的增加，各金属元素测定结果均呈下降趋势，而RSD有上升趋势。土壤粒径对测定结果的影响较小，随着土壤粒径减少，各金属元素测定结果的RSD略有下降趋势。PXRF可以简单、快速地测定多种重金属元素，适用于污染地块重金属元素的现场实时监测。

Application of Portable X ray Fluorescence Spectrometer in the Investigation of Contaminated Site

The performance of portable X ray fluorescence spectrometer (PXRF) for detecting As, Pb, Cr, Cu, Zn and Ni in soils was studied, including detection limit, precision and accuracy. The influence of soil moisture content and particle size on the PXRF determination results was explored. The detection results between PXRF and conventional laboratory detection methods were compared for further evaluation. The results showed that the detection limits of As, Pb, Cr, Cu, Zn and Ni were between 5 and 15 mg/kg, where the relative standard deviations of reference materials detection results were not greater than 8.6%, and the relative errors were within ±15%. With an increase in the soil moisture content, an overall decrease in the detection results of each element was observed, along with an increasing RSD. The soil particle size had little effect on the detection results, and with the decrease of soil particle size, the RSD showed a slightly decreasing trend. This work demonstrates that PXRF could be used for determination of various heavy metals in a simple and rapid way, which is suitable for on site and real time investigation of heavy metals in contaminated sites.