直接进样-全反射X射线荧光光谱快速测定饮用水微量元素

doi:10.3964/j.issn.1000-0593(2023)03-0990-07

摘要
参考文献
相关文章 (15)

全文: PDF (4257 KB)
输出: BibTeX | EndNote (RIS)

摘要：相比于复杂的富集程序，饮用水中由于金属元素含量甚微，急需一种快速，简单和可靠的检测方法。全反射X射线荧光光谱法（TXRF）是一种方便快捷、定量简单的微量多元素同步分析方法，该方法所需要的样品少，测量时间短，无需预处理可实现对样品的直接分析。以镓（Ga）为内标，采用直接进样-TXRF法，探究了快速测定多质量浓度梯度多元素金属溶液的可行性，并将该方法应用于低矿物质饮用水中进行微量元素分析。实验结果表明，TXRF能直接提取溶液中的Al、K、Ca、Mn、Fe、Co、Ni、Cu、Zn、Sr进行同步测量，但是多次试验发现，Al、K、Ca作为轻质元素由于回收率明显偏离标准值，难以实现准确定量，究其原因是基体效应较大或元素的灵敏度较低，而其他元素均满足定量要求。通过对不同浓度梯度的标准样品进行测量，发现当金属元素浓度分别处于40 mg·L^-1、4 mg·L^-1、0.4 mg·L^-1、40 μg·L^-1水平时，Mn、Fe、Co、Ni、Cu、Zn、Sr元素均呈现出很好的准确度和精密度，回收率（RR）稳定在80%～112%，相对标准偏差（RSD）处于3.6%～10.5%，检出限（DL）处于0.001～0.07 mg·L^-1。随着浓度梯度的逐渐下降，各元素的准确度和精密度开始表现出不同程度的下降，当质量浓度处于本文试验最低水平4 μg·L^-1时，大部分元素（Mn除外）的回收率和RSD均明显偏离标准值。还利用直接进样-TXRF法，在低、中、高三个不同加标水平下对饮用矿物质水进行加标回收试验，结果表明，样本中Mn、Fe、Co、Ni、Cu、Zn、Sr元素含量基本处于几十个μg·L^-1水平，平均加标回收率在90%～110%之间，平均RSD小于12%，满足微量测定要求。综上所述，多元素测试结果表明，TXRF在对元素的选择上更适宜原子序数（Z>20）的中等重元素，对于组分含量在十几个μg·L^-1以上的水质样品，无需经过复杂预处理，可直接实现快速准确定量分析，对于环境中的超痕量样品需要使用预浓缩技术以提高测量准确率。

关键词：全反射X射线荧光光谱法；快速；多元素；低矿化质水；金属元素

Abstract：Compared with the complicated enrichment procedure, a rapid, simple and reliable method is urgently needed to determine trace metal elements in drinking water. Total reflection X-ray Fluorescence spectrometry (TXRF) is a convenient and quantitative method for simultaneous analysis of trace multi-metal elements requiring less samples and short measured time and can be analysed directly without samples pretreatment. In this paper, Ga was used as the internal standard. The feasibility of rapid determination of multi-mass concentration gradient and the multi-element metal solution was explored by direct injection-TXRF method and then applied to the low mineral drinking water for the trace metal elements analysis. The experimental results showed that Al, K, Ca, Mn, Fe, Co, Ni, Cu, Zn and Sr can be analyzed immediately. However, the experiment results found that Al, K and Ca, as light elements, are difficult to achieve accurate quantification due to the recovery rate deviating from the standard value, the reason for the high matrix effect and low elements sensitivity. In contrast, other elements achieve the quantitative requirements. It was found that Mn, Fe, Co, Ni, Cu, Zn and Sr showed good accuracy and precision when the concentrations of metal elements were 40 mg·L^-1, 4 mg·L^-1, 0.4 mg·L^-1 and 40 μg·L^-1, respectively. The Recovery Rate (RR) was 80%～112%. The relative Standard Deviation (RSD) was 3.6%～10.5%, and the Detection Limit (DL) was 0.001～0.07 mg·L^-1. With the decrease in the concentration gradient, the accuracy and precision appeared to have different degrees of decline. When the mass concentration was at the lowest level of 4 μg·L^-1 in this experiment, the RR and RSD of most elements (except Mn) significantly deviated from the standard value. This paper used the direct injection-TXRF method to test the RR of drinking mineral water at low, medium and high levels. The results showed that Mn, Fe, Co, Ni, Cu, Zn and Sr in the samples were basically at the concentration of μg·L^-1 levels, the average RR ranged from 90% to 110%, and the average RSD was less than 12%, which met the qualification of micro estimation. In summary, Multi-element test results showed that TXRF is more suitable for heavy elements (Z>20) in selecting elements. Water samples with more than ten components of μg·L^-1 level can directly achieve rapid and accurate quantitative analysis without complex pretreatment for enrichment. Preconcentration techniques are needed to improve the accuracy of ultra-trace level samples in the environment.

Key words：TXRF; Rapid;Multi-element Analysis;Low mineral water; Metal element

收稿日期: 2022-02-22 修订日期: 2022-06-16

中图分类号:

X832

基金资助: 国家自然科学基金创新研究群体项目（62021003）资助

通讯作者: 彭永臻 E-mail: pyz@bjut.edu.cn

作者简介: 吴蕾，女，1982年生，北京工业大学城镇污水深度处理与资源化利用技术国家工程实验室实验师 e-mail: wulei@bjut.edu.cn

引用本文:

吴蕾，李凌云，彭永臻. 直接进样-全反射X射线荧光光谱快速测定饮用水微量元素[J]. 光谱学与光谱分析, 2023, 43(03): 990-996.
WU Lei, LI Ling-yun, PENG Yong-zhen. Rapid Determination of Trace Elements in Water by Total Reflection X-Ray Fluorescence Spectrometry Using Direct Sampling. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2023, 43(03): 990-996.

链接本文:

https://www.gpxygpfx.com/CN/10.3964/j.issn.1000-0593(2023)03-0990-07 或 https://www.gpxygpfx.com/CN/Y2023/V43/I03/990