This work introduces a new gradient fiber coating for microextraction of chlorobenzenes. Nanoclusters of organoclay-Cu(II) on a copper wire were fabricated by wireless electrofunctionalization. The resultant gradient coatings are more robust, and thermally and mechanically stable. Wireless electrofunctionalization was carried out in a bipolar cell under a constant deposition potential and using an ethanolic electrolyte solution containing stearic acid and montmorillonite. Stearic acid acts as an inexpensive and green coating while montmorillonite acts as a modifier to impart thermal stability. The gradient morphology of the nanoclusters was investigated by scanning electron microscopy, thermogravimetric analysis and energy dispersive X-ray spectroscopy. The coated wire was placed in a hollow needle and used for headspace in-tube microextraction (HS–ITME) of chlorobenzenes (CBs). Effects of various parameters affecting synthesis and extraction were optimized. Following extraction, the needles were directly inserted into the GC injector, and the CBs (chlorobenzene, 1,4-dichlorobenzene, 1,2-dichlorobenzene, 1,2,4-trichlorobenzene, 1,2,3,4-tetrachlorobenzene) were quantified by GC–MS. The limits of detection under optimized conditions range from 0.5 to 10 ng.L−1. The intra– and inter–day relative standard deviations (RSDs) (for n = 10, 5 respectively) using a single fiber are 6–10 and 10–15%, respectively. The fiber–to–fiber RSDs (for n = 3) is between 17 and 24%. The method was successfully applied to the extraction of CBs from real water samples, and relative recoveries are between 91 and 110%.Graphical abstractA gradient coating of organoclay–Cu nanoclusters was fabricated on a copper wire by wireless electrofunctionalization. The oxidation of copper takes place at the anodic pole (red) while dissolved oxygen in ethanol solution is reduced at the cathodic pole (blue).

中文翻译：

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由铜（II）、硬脂酸和蒙脱石组成的梯度纳米团簇在铜线上的无线电化学制备用于顶空管内微萃取氯苯

这项工作介绍了一种用于微萃取氯苯的新型梯度纤维涂层。通过无线电功能化制造了铜线上的有机粘土-Cu(II) 纳米团簇。由此产生的梯度涂层更坚固，并且在热和机械上更稳定。无线电功能化是在双极电池中在恒定沉积电位下使用含有硬脂酸和蒙脱石的乙醇电解质溶液进行的。硬脂酸作为一种廉价的绿色涂层，而蒙脱石作为一种改性剂来赋予热稳定性。通过扫描电子显微镜、热重分析和能量色散 X 射线光谱研究了纳米团簇的梯度形态。将涂层线置于空心针中，用于氯苯 (CB) 的顶空管内微萃取 (HS-ITME)。优化了影响合成和提取的各种参数的影响。萃取后，将针头直接插入 GC 进样器，将 CB（氯苯、1,4-二氯苯、1,2-二氯苯、1,2,4-三氯苯、1,2,3,4-四氯苯） GC-MS 定量。优化条件下的检测限范围为 0.5 至 10 ng.L-1。使用单根纤维的日内和日间相对标准偏差 (RSD)（分别为 n = 10、5）分别为 6–10% 和 10–15%。光纤到光纤的 RSD（n = 3）介于 17% 和 24% 之间。该方法成功应用于实际水样中CBs的提取，相对回收率在91%~110%之间。图形摘要通过无线电功能化在铜线上制备了有机粘土-Cu 纳米团簇的梯度涂层。铜的氧化发生在阳极（红色），而乙醇溶液中的溶解氧在阴极（蓝色）处减少。