Environmental Science Research Laboratory, Central Research Institute of Electric Power Industry, Abiko City, Chiba, Japan.
Anal Chem. 2013 Jan 2;85(1):434-40. doi: 10.1021/ac3032146. Epub 2012 Dec 12.
Mercury is considered the most important heavy-metal pollutant, because of the likelihood of bioaccumulation and toxicity. Monitoring widespread ionic mercury (Hg(2+)) contamination requires high-throughput and cost-effective methods to screen large numbers of environmental samples. In this study, we developed a simple and sensitive analysis for Hg(2+) in environmental aqueous samples by combining a microfluidic immunoassay and solid-phase extraction (SPE). Using a microfluidic platform, an ultrasensitive Hg(2+) immunoassay, which yields results within only 10 min and with a lower detection limit (LOD) of 0.13 μg/L, was developed. To allow application of the developed immunoassay to actual environmental aqueous samples, we developed an ion-exchange resin (IER)-based SPE for selective Hg(2+) extraction from an ion mixture. When using optimized SPE conditions, followed by the microfluidic immunoassay, the LOD of the assay was 0.83 μg/L, which satisfied the guideline values for drinking water suggested by the United States Environmental Protection Agency (USEPA) (2 μg/L; total mercury), and the World Health Organisation (WHO) (6 μg/L; inorganic mercury). Actual water samples, including tap water, mineral water, and river water, which had been spiked with trace levels of Hg(2+), were well-analyzed by SPE, followed by microfluidic Hg(2+) immunoassay, and the results agreed with those obtained from reduction vaporizing-atomic adsorption spectroscopy.
汞被认为是最重要的重金属污染物，因为它具有生物累积性和毒性。监测广泛存在的离子态汞（Hg(2+)）污染需要高通量且具有成本效益的方法来筛选大量环境样本。在这项研究中，我们通过将微流控免疫分析和固相萃取（SPE）相结合，开发了一种用于环境水样中 Hg(2+)的简单、灵敏的分析方法。使用微流控平台，开发了一种超灵敏的 Hg(2+)免疫分析方法，仅需 10 分钟即可得出结果，检测限（LOD）低至 0.13μg/L。为了使开发的免疫分析能够应用于实际的环境水样，我们开发了一种基于离子交换树脂（IER）的 SPE，用于从离子混合物中选择性提取 Hg(2+)。当使用优化的 SPE 条件并结合微流控免疫分析时，该分析方法的 LOD 为 0.83μg/L，满足了美国环境保护署（USEPA）（2μg/L；总汞）和世界卫生组织（WHO）（6μg/L；无机汞）建议的饮用水指导值。实际水样，包括自来水、矿泉水和河水，经痕量 Hg(2+)添加后，通过 SPE 和微流控 Hg(2+)免疫分析进行了很好的分析，结果与还原蒸发-原子吸收光谱法的结果一致。
