梁嘉斌, 郭嘉明, 郭尧平, 陈纠, 刘移民. 原子荧光法测定尿中砷的方法优化及分析[J]. 环境与职业医学, 2021, 38(3): 303-307. DOI: 10.13213/j.cnki.jeom.2021.20468
引用本文: 梁嘉斌, 郭嘉明, 郭尧平, 陈纠, 刘移民. 原子荧光法测定尿中砷的方法优化及分析[J]. 环境与职业医学, 2021, 38(3): 303-307. DOI: 10.13213/j.cnki.jeom.2021.20468
LIANG Jiabin, GUO Jiaming, GUO Yaoping, CHEN Jiu, LIU Yimin. Optimization of atomic fluorescence spectrometry for determination of arsenic in urine[J]. Journal of Environmental and Occupational Medicine, 2021, 38(3): 303-307. DOI: 10.13213/j.cnki.jeom.2021.20468
Citation: LIANG Jiabin, GUO Jiaming, GUO Yaoping, CHEN Jiu, LIU Yimin. Optimization of atomic fluorescence spectrometry for determination of arsenic in urine[J]. Journal of Environmental and Occupational Medicine, 2021, 38(3): 303-307. DOI: 10.13213/j.cnki.jeom.2021.20468

原子荧光法测定尿中砷的方法优化及分析

Optimization of atomic fluorescence spectrometry for determination of arsenic in urine

  • 摘要: 背景

    我国尿砷检测的卫生行业标准未明确消化温度和电热板性能,导致不同实验室尿砷前处理方式存在较大差异。

    目的

    分析湿式消解-原子荧光法测定尿中砷结果偏低的原因,并对标准方法进行优化。

    方法

    以WS/T 474—2015《尿中砷的测定氢化物发生原子荧光法》推荐的步骤为基础,使用标准方法(150℃消解、220℃消解)和梯度升温方法(150℃消解1h,220℃消解1h,320℃消解30 min,消解赶酸至白烟散尽)对样品进行前处理,比对原子荧光法和ICP-MS法对尿液(高砷暴露的正常人群、服用砷剂病人和砒霜中毒病人)总砷和无机砷(亚砷酸根和砷酸根)、有机砷(砷甜菜碱和砷胆碱)标准品的测定结果。优化尿中砷测定的湿式消解-原子荧光法,并对其线性、检出限、定量下限、精密度、准确度和抗干扰能力等性能指标进行验证。

    结果

    150℃和220℃湿式消解原子荧光光谱法测定的结果回收率均低于90%,而梯度升温到320℃的湿式消解荧光光谱法测定结果与ICP-MS法接近,回收率为97.92%~101.16%。经过150℃和220℃的湿式消解,砷甜菜碱和砷胆碱几乎无法测出,回收率极低;梯度升温到320℃的湿式消解荧光光谱法测定砷甜菜碱和砷胆碱的回收率分别为97.59%和99.96%。该方法在尿砷含量为5.0~40.0 μg·L-1时,线性关系良好,相关系数为0.999 7,最低检出限为0.06 μg·L-1,定量下限为0.18 μg·L-1,相对标准偏差为0.95%~3.24%,加标回收率为95.95%~103.10%。200倍于砷水平的铅、锌、镉、铜、硒、汞、锑、铁、铝和锰等金属离子干扰物对测定结果所造成的偏差 < ±10%。

    结论

    标准方法由于消解温度偏低,不能有效消解砷甜菜碱和砷胆碱等有机砷。本研究优化后的湿式消解-原子荧光法能有效消解尿中的有机砷,各项性能指标通过验证实验,适用于尿液中总砷的测定。

     

    Abstract: Background

    The digestion temperature and the performance parameters of electric heating plate are not clearly defined in the health industry standards for the detection of arsenic in urine in China, which leads to great differences in the pretreatment methods of urinary arsenic in different laboratories.

    Objective

    This study analyzes the causes for reporting lower detection results of arsenic in urine by wet digestion-atomic fluorescence spectrometry than by ICP-MS, and optimizes the standard method.

    Methods

    According to WS/T 474-2015 Determination of arsenic in urine by hydride generation atomic fluorescence spectrometry, the standard method (150℃ digestion, 220℃ digestion) and the gradient heating method (150℃ digestion for 1 h, 220℃ digestion for 1 h, 320℃ digestion for 30 min, till white fumes were evolved) were used for sample preparation. The determination results of total arsenic, inorganic arsenic (arsenite and arsenate), and organic arsenic (arsenic betaine and arsenic choline) in urinary samples (from healthy people with high arsenic exposure, patients taking arsenic trioxide, and patients with arsenic poisoning) by atomic fluorescence spectrometry and ICP-MS were compared. The wet digestion-atomic fluorescence spectrometry was optimized for the determination of arsenic in urine, and its performance indicators such as linearity, detection limit, lower limit of quantification, precision, accuracy, and anti-interference ability were verified.

    Results

    The recoveries of 150℃ and 220℃ wet digestion-atomic fluorescence spectrometry were lower than 90%, while the results of wet digestion-fluorescence spectrometry with gradient heating to 320℃ were close to those of ICP-MS, ranging from 97.92% to 101.16%. After wet digestion at 150℃ and 220℃, arsenic betaine and arsenic choline were hardly detected, and the recovery rates were extremely low; after gradient heating to 320℃, the recovery rates were 97.59% and 99.96%. By combining gradient heating and wet digestion-atomic fluorescence method, when the urinary arsenic concentration was 5.0-40.0 μg·L-1, the linear relationship was good, the correlation coefficient was 0.999 7, the detection limit was 0.06 μg·L-1, the lower limit of quantification was 0.18 μg·L-1, the relative standard deviation (RSD) was 0.95%-3.24%, and the recoveries were 95.95%-103.10%. Lead, zinc, cadmium, copper, selenium, mercury, antimony, iron, aluminum, and manganese at 200 times the concentration of arsenic caused a deviation of < ±10% in the measurement results.

    Conclusion

    The standard method can not effectively remove arsenic betaine and arsenic choline due to the low digestion temperature. In this study, the optimized wet digestion-atomic fluorescence spectrometry can effectively remove organic arsenic in urine, and the performance indicators are validated; therefore, the improved method is suitable for the determination of total arsenic in urine.

     

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