A preconcentration method based on the use of graphene oxide (GO) functionalized with an ionic liquid (IL) was developed for trace Hg determination in water samples. The IL–GO hybrid nanomaterial was prepared by a simple procedure to functionalize GO with the IL 1-butyl-3-dodecylimidazolium bromide ([C₄C₁₂im]Br) and its performance as a sorption material for Hg was evaluated. A microcolumn filled with the IL–GO nanomaterial was used for preconcentration and determination of Hg followed by electrothermal atomic absorption spectrometry (ETAAS) detection. Mercury was retained at pH 5.0 and 20% (v/v) HNO₃ was used for the elution of Hg from the microcolumn. The effects of different variables, including the sample volume, extraction time, sample flow rate, type and concentration of eluent and eluent flow rate were carefully studied. High retention efficiency (100%) was achieved with the proposed IL–GO sorption nanomaterial without the need for additional chelating reagents or derivatization reagents, which is an important advantage compared with traditional preconcentration methods. A sensitivity enhancement factor of 100 and a low detection limit of 14 ng L⁻¹ were obtained under optimal experimental conditions. The proposed method can be considered as a simple, cost-effective and efficient alternative for Hg determination in water samples like river, rain, mineral and tap water.

中文翻译：

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一种易于制备的氧化石墨烯-离子液体杂化纳米材料，用于微固相萃取和水样品中汞的预浓缩†

开发了一种基于使用经离子液体（IL）官能化的氧化石墨烯（GO）的预浓缩方法，用于测定水中的痕量汞。通过简单的程序制备IL-GO杂化纳米材料，以用IL 1-丁基-3-十二烷基咪唑鎓溴化物（[C ₄ C ₁₂ im] Br）官能化GO，并评估了其作为汞吸附材料的性能。填充有IL-GO纳米材料的微柱用于预富集和测定Hg，然后进行电热原子吸收光谱法（ETAAS）检测。汞保留在pH 5.0和20％（v / v）HNO _3中将其用于从微柱中洗脱Hg。仔细研究了不同变量的影响，包括样品量，提取时间，样品流速，洗脱液的类型和浓度以及洗脱液流速。提出的IL-GO吸附纳米材料可实现高保留效率（100％），而无需其他螯合剂或衍生化试剂，与传统的预浓缩方法相比，这是一个重要的优势。在最佳实验条件下获得了100的灵敏度增强因子和14 ng L ^-1的低检测限。所提出的方法可以被认为是一种简单，经济高效的测定水中，河水，雨水，矿物质和自来水中汞的方法。