High-accuracy determination of trace elements by total reflection X-ray fluorescence spectrometry using freeze-dried specimens
High-accuracy determination of trace elements by total reflection X-ray fluorescence spectrometry using freeze-dried specimens
复制标题
使用冻干样品的全反射 X 射线荧光光谱法高精度测定微量元素
DOI：
10.1039/d2an01290a
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发表时间：
2022
期刊：
影响因子：
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通讯作者：
Tsuji Kouichi
中科院分区：
文献类型：
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作者：
Matsuyama Tsugufumi;Tanaka Yudai;Nakae Masanori;Furusato Takumi;Tsuji Kouichi
全反射X射线荧光(TXRF)分析用于测定滴在基质上并干燥的样品溶液中的痕量元素。因此，残留物的形式会影响定量结果。X射线荧光(XRF)的吸收服从朗伯-比尔定律；XRF在厚渣(点状残渣)中的吸收作用比在薄渣(膜型残渣)中的吸收作用强。在测定高元素浓度溶液中的低Z元素时，吸收效果尤为显著。在这项研究中，我们提出了一种新的基于冷冻干燥方法的薄膜状残留物制备工艺，以获得准确的TXRF结果。将样品溶液滴到衬底上并插入到腔室中。用液氮冷却小室，结果是冻结了一分之的样品。使用真空泵对腔体进行减压，并通过将腔体保持在室温下来制备冻干残渣。为了评价基于冷冻干燥的样品制备方法在TXRF分析中的效率，我们制备了一种含有高元素浓度成分的多元素溶液。对于冻干法制备的残留物，由于吸收作用减弱，定量的相对标准偏差和最小检出限都有所提高。基于冷冻干燥方法的样品制备过程有助于对高元素浓度溶液进行准确的TXRF分析，并可用于环境水和废水等不同类型溶液中痕量元素的分析。
Total reflection X-ray fluorescence (TXRF) analysis is conducted to determine trace elements in a sample solution, which is dropped onto a substrate and dried. Therefore, the form of the residue affects the quantitative results. The absorption of X-ray fluorescence (XRF) follows the Lambert–Beer law; the absorption effect of XRF in a thick residue (dotted-type residue) is stronger than that in a thin residue (film-type residue). The absorption effect is particularly remarkable during the determination of low-Z elements in a high-elemental concentration solution. In this study, we propose a new film-like-residue preparation process based on the freeze-drying method to obtain accurate TXRF results. The sample solution is dropped onto the substrate and inserted into a chamber. The chamber is cooled using liquid nitrogen; resultantly, an aliquot of the sample is frozen. The chamber is depressurized using a vacuum pump, and the freeze-dried residue is prepared by maintaining the chamber at room temperature. To evaluate the efficiency of the freeze-drying-based method for sample preparation for TXRF analysis, we prepare a multi-element solution containing high-elemental concentration components. For the residue prepared using the freeze-drying method, the relative standard deviations of the quantitative values and the minimum detection limits are improved because the absorption effect is weakened. The sample preparation process based on the freeze-drying method facilitates accurate TXRF analysis of high-elemental concentration solutions and can be applied for the analysis of trace elements in different types of solutions such as environmental water and wastewater.