Marsay N H, Wagland S T, Campo P, Alamar M C
Faculty of Engineering and Applied Sciences, Cranfield University, Cranfield, Bedfordshire, UK.
Environ Geochem Health. 2025 Jul 5;47(8):298. doi: 10.1007/s10653-025-02574-x.
Portable X-ray fluorescence spectroscopy (pXRF) is widely used for rapid measurement of metals in soils, however, thorough evaluation of common pre-processing methods and their effectiveness is limited. This study addresses processing methods using samples collected at a highly heterogeneous post-metallurgical site containing, basic oxygen steelmaking (BOS) slag and soil; the former being an important source of potentially toxic and valuable elements. Impact of pre-treatment processes, (sieving, drying, grinding, sample vessel, and ignition) on the accuracy of pXRF measurements was compared against reference ICP-MS measurements.Of the twelve elements detected, four showed qualitative (Cr and Fe r ≥ 0.60, RSD ≤ 30%) or quantitative (Mn and Ca r ≥ 0.70, RSD ≤ 20%) measurements for raw samples. Improving to six elements after pre-processing (Sr qualitative, and Pb, Cr, Mn, Ca, Fe quantitative). Sieving and grinding improved precision (average RSD fell by 7.17 and 8.37% respectively), while drying and grinding enhanced accuracy (average r increased by 0.03 and 0.10 respectively). This study provides the first evidence that organic matter does not significantly impact pXRF accuracy or precision (average r and RSD changed by zero and - 0.32%, respectively). The two distinct matrices (BOS slag and soil) on-site resulted in a bimodal concentration distribution and a negative correlation for Ti. Importantly, this research proposes that not all common pre-processing steps are necessary to generate high-quality data due to their negligible impact on accuracy or precision (such as incineration to remove organic matter), thereby increasing the speed and reducing the cost of data collection.
便携式X射线荧光光谱法（pXRF）被广泛用于快速测量土壤中的金属，然而，对常见预处理方法及其有效性的全面评估却很有限。本研究针对在一个高度异质的冶金后场地采集的样品，该场地含有碱性氧气炼钢（BOS）炉渣和土壤；前者是潜在有毒和有价值元素的重要来源。将预处理过程（筛分、干燥、研磨、样品容器和灼烧）对pXRF测量准确性的影响与参考电感耦合等离子体质谱（ICP-MS）测量结果进行了比较。在检测到的12种元素中，有4种元素在原始样品中显示出定性（Cr和Fe，r≥0.60，相对标准偏差≤30%）或定量（Mn和Ca，r≥0.70，相对标准偏差≤20%）测量结果。预处理后提高到6种元素（Sr定性，Pb、Cr、Mn、Ca、Fe定量）。筛分和研磨提高了精度（平均相对标准偏差分别下降了7.17%和8.37%），而干燥和研磨提高了准确性（平均r分别增加了0.03和0.10）。本研究首次证明有机物不会显著影响pXRF的准确性或精度（平均r和相对标准偏差分别变化了零和 -0.32%）。现场的两种不同基质（BOS炉渣和土壤）导致了双峰浓度分布和Ti的负相关。重要的是，本研究提出，并非所有常见的预处理步骤对于生成高质量数据都是必要的，因为它们对准确性或精度的影响可忽略不计（例如焚烧以去除有机物），从而提高了数据收集的速度并降低了成本。
