Amde Meseret, Liu Jing-Fu, Tan Zhi-Qiang, Bekana Deribachew
State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P. O. Box 2871, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P. O. Box 2871, Beijing 100085, China; Institute of Environment and Health, Jianghan University, Hubei Province, Wuhan 430056, China.
Talanta. 2016;149:341-346. doi: 10.1016/j.talanta.2015.12.004. Epub 2015 Dec 4.
Zinc oxide nanofluid (ZnO-NF) based vortex assisted liquid liquid microextraction (ZnO-NF VA-LLME) was developed and employed in extraction of inorganic mercury (Hg(2+)) in environmental water samples, followed by cold vapor atomic fluorescence spectrometry (CV-AFS). Unlike other dispersive liquid liquid microextraction techniques, ZnO-NF VA-LLME is free of volatile organic solvents and dispersive solvent consumption. Analytical signals were obtained without back-extraction from the ZnO-NF phase prior to CV-AFS determination. Some essential parameters of the ZnO-NF VA-LLME and cold vapor generation such as composition and volume of the nanofluid, vortexing time, pH of the sample solution, amount of the chelating agent, ionic strength and matrix interferences have been studied. Under optimal conditions, efficient extraction of 1ng/mL of Hg(2+) in 10mL of sample solution was achieved using 50μL of ZnO-NF. The enrichment factor before dilution, detection limits and limits of quantification of the method were about 190, 0.019 and 0.064ng/mL, respectively. The intra and inter days relative standard deviations (n=8) were found to be 4.6% and 7.8%, respectively, at 1ng/mL spiking level. The accuracy of the current method was also evaluated by the analysis of certified reference materials, and the measured Hg(2+) concentration of GBW08603 (9.6ng/mL) and GBW(E)080392 (8.9ng/mL) agreed well with their certified value (10ng/mL). The method was applied to the analysis of Hg(2+) in effluent, influent, lake and river water samples, with recoveries in the range of 79.8-92.8% and 83.6-106.1% at 1ng/mL and 5ng/mL spiking levels, respectively. Overall, ZnO-NF VA-LLME is fast, simple, cost-effective and environmentally friendly and it can be employed for efficient enrichment of the analyte from various water samples.
基于氧化锌纳米流体（ZnO-NF）的涡旋辅助液液微萃取（ZnO-NF VA-LLME）技术被开发并应用于环境水样中无机汞（Hg(2+)）的萃取，随后采用冷蒸气原子荧光光谱法（CV-AFS）进行测定。与其他分散液液微萃取技术不同，ZnO-NF VA-LLME无需使用挥发性有机溶剂，也不消耗分散剂。在进行CV-AFS测定之前，无需从ZnO-NF相中进行反萃取即可获得分析信号。研究了ZnO-NF VA-LLME和冷蒸气发生的一些关键参数，如纳米流体的组成和体积、涡旋时间、样品溶液的pH值、螯合剂的用量、离子强度和基质干扰等。在最佳条件下，使用50μL的ZnO-NF可在10mL样品溶液中高效萃取1ng/mL的Hg(2+)。该方法稀释前的富集因子、检测限和定量限分别约为190、0.019和0.064ng/mL。在1ng/mL加标水平下，日内和日间相对标准偏差（n = 8）分别为4.6%和7.8%。通过分析有证标准物质对本方法的准确性进行了评估，GBW08603（9.6ng/mL）和GBW(E)080392（8.9ng/mL）中Hg(2+)的测定浓度与它们的认定值（10ng/mL）吻合良好。该方法应用于废水、进水、湖水和河水样品中Hg(2+)的分析，在1ng/mL和5ng/mL加标水平下，回收率分别在79.8 - 92.8%和83.6 - 106.1%范围内。总体而言，ZnO-NF VA-LLME快速、简单、经济高效且环境友好，可用于从各种水样中高效富集分析物。
