Institute of Analytical and Bioanalytical Chemistry, University of Ulm, Ulm, Germany.
Anal Bioanal Chem. 2012 Jun;403(8):2419-28. doi: 10.1007/s00216-012-5851-8. Epub 2012 Apr 25.
A fully automated online ultraviolet (UV) digestion method for subsequent mercury (Hg) quantification in humic matter containing river waters is reported. The new developed flow injection analysis system (FIAS) consists basically of a UV lamp, a meander-form quartz glass reaction tube for online irradiation of the sample, and a nano-gold collector for preconcentration of dissolved mercury species. The FIAS is coupled to an atomic fluorescence spectrometer (AFS) for Hg detection. The optimized procedure allows accurate mercury quantification in water samples with up to 15 mg CL(-1) as dissolved organic carbon by addition of only 1% (v/v) of hydrogen peroxide solution and online UV irradiation for 6 min. Addition of strong oxidants and any other reagents is avoided due to the use of the catalytic active nano-gold collector. Here, preconcentration of Hg species, release of mercury as Hg(0), and AFS measurement are performed without addition of any reagents. Hence, the proposed approach offers significant advantages over existing methods. Analytical figures of merit showed the good performance of the developed method: The limit of quantification was found to be as low as 0.14 ng Hg L(-1). The linear working range is from 0.1 to 200 ng Hg L(-1) and relative standard deviation is <6.0% (n = 9). The system was successfully validated by comparison of the mercury concentrations found in model and real water samples obtained by the reference method EPA 1631 and the proposed method. Furthermore, application to six real river waters confirmed the feasibility of the proposed approach.
本文报道了一种全自动在线紫外（UV）消解方法，用于随后对含有腐殖质的河水中的汞（Hg）进行定量分析。新开发的流动注射分析系统（FIAS）基本由 UV 灯、用于在线辐照样品的曲折形石英玻璃反应管和用于溶解汞形态预浓缩的纳米金收集器组成。FIAS 与原子荧光光谱仪（AFS）耦合用于 Hg 检测。该优化程序允许在添加仅 1%（v/v）过氧化氢溶液并在线辐照 6 分钟的情况下，准确测定高达 15 mg CL(-1)作为溶解有机碳的水样中的汞。由于使用了催化活性纳米金收集器，避免了添加强氧化剂和任何其他试剂。在这里，Hg 形态的预浓缩、Hg(0)的释放和 AFS 测量在不添加任何试剂的情况下进行。因此，该方法与现有方法相比具有显著优势。分析的衡量标准表明该方法具有良好的性能：检测限低至 0.14 ng Hg L(-1)。线性工作范围为 0.1 至 200 ng Hg L(-1)，相对标准偏差<6.0%（n = 9）。通过比较 EPA 1631 参考方法和本方法测定的模型和实际水样中的汞浓度，验证了该系统的有效性。此外，该方法应用于六个实际河流水样，证实了该方法的可行性。
