pH-dependent selective ion exchange based on (ethylenediamintetraacetic acid-nickel)-layered double hydroxide to catalyze the polymerization of aniline for detection of Cu2+ and Fe3+
pH-dependent selective ion exchange based on (ethylenediamintetraacetic acid-nickel)-layered double hydroxide to catalyze the polymerization of aniline for detection of Cu2+ and Fe3+
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基于（乙二胺四乙酸-镍）层状双氢氧化物的 pH 依赖性选择性离子交换催化苯胺聚合用于检测 Cu2 和 Fe3
DOI：
10.1016/j.talanta.2018.04.102
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发表时间：
2018
期刊：
影响因子：
6.1
通讯作者：
Lee Hian Kee
中科院分区：
文献类型：
--
作者：
Tang Sheng;Sun Jun;Li Yana;Xia Dasha;Qi Tong;Liu Kai;Deng Huimin;Shen Wei;Lee Hian Kee
建立了一种pH依赖的选择性离子交换-苯胺催化聚合体系，用于铜（Cu ~（2+））和铁（Fe ~（3+））的灵敏检测。采用共沉淀法将乙二胺四乙酸（EDTA）与镍离子（Ni ~（2+））螯合，插层于层状双氢氧化物中。该产品随后被用作吸附剂富集Cu 2+在pH 6.5和Fe 3+在pH 4.5。由于Cu ~（2+）和Fe ~（3+）与EDTA有较强的络合形成常数，Ni ~（2+）选择性地与Cu ~（2+）/Fe ~（3+）交换。该吸附剂在不同pH值下均能有效释放Cu 2 +/Fe 3+，对苯胺聚合反应具有较高的催化能力，因此将该吸附剂用于催化苯胺聚合反应。在不同的pH值下产生具有不同颜色的聚苯胺，这一观察结果用于区分Cu 2+和Fe 3+的比色信号。对提取温度、提取时间、催化时间和pH值进行了优化。结果表明，该方法对Cu 2+和Fe 3+的检测限分别为0.1 nM（6.4 ng/L）和1 nM（56 ng/L），线性范围宽（分别为0.0005-2.5 μM和0.005-5 μM），线性关系良好（r2值分别为0.9904和0.9965）。将优化后的方法应用于河水样品。以Cu ~（2+）/Fe ~（3+）为例，本工作为水溶液中金属离子的方便、高效检测提供了一种新的方法。
A pH-dependent selective ion exchange coupled with catalytic polymerization of aniline has been developed for sensitive detection of copper (Cu2+) and ferric ions (Fe3+). Ethylenediamintetraacetic acid (EDTA) chelated with nickel ion (Ni2+) were intercalated in a layered double hydroxide via a co-precipitation reaction. The product was subsequently applied as sorbent for the enrichment of Cu2+at pH 6.5 and Fe3+at pH 4.5. Since both Cu2+and Fe3+have stronger complex formation constants with EDTA, Ni2+exchanges with Cu2+/Fe3+selectively. The resulting sorbent containing Cu2+/Fe3+was transferred to catalyze the aniline polymerization reaction, since Cu2+/Fe3+could be released by the sorbent effectively at different pH values and have high catalytic abilities for the polymerization reaction. The resulting polyaniline with different colors were produced at different pH values, an observation that was utilized to distinguish between the colorimetric signals of Cu2+and Fe3+. The extraction temperature, extraction time, catalysis time and pH were optimized. The results showed that this method provided low limits of detection of 0.1 nM (6.4 ng/L) for Cu2+, 1 nM (56 ng/L) for Fe3+, wide linear ranges (0.0005–2.5 µM, and 0.005–5 µM, respectively), and good linearities (r2values of 0.9904, and 0.9965, respectively). The optimized method was applied to river water samples. Using Cu2+/Fe3+as examples, this work provided a new and interesting approach for the convenient and efficient detection of metal ions in aqueous samples.