Xiong Chenyu, Hui Yun, Wang Ri, Bian Chao, Xu Yuhao, Xie Yong, Han Mingjie, Xia Shanhong
State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, China.
School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.
Micromachines (Basel). 2021 Nov 27;12(12):1461. doi: 10.3390/mi12121461.
Trace mercury ion (Hg2+) detection is important for environmental monitoring and water safety. In this work, we study the electrochemical strategy to detect trace Hg2+ based on the preconcentration of temperature-controlled N-octylpyridinium tetrafluoroborate ([OPy][BF4]) dispersive liquid-liquid microextraction. The [OPy][BF4] selectively extracted Hg2+ from aqueous solution by the adsorption of unsaturated N in [OPy][BF4], which increased the concentration of Hg2+ and decreased that of other interference ions. It was noted that the adsorption of [OPy][BF4] to Hg2+ was weakened by aqueous solution. Hence, after extraction, precipitated [OPy][BF4] was diluted by a buffer solution comprising a mixture of water and acetonitrile to release Hg2+ and the single was detected by electrochemistry. Water is proposed to release Hg2+ adsorbed by [OPy][BF4], and the acetonitrile serves as a co-solvent in buffer solution. Sensitivity and anti-inference ability of sensors were improved using the proposed method and Hg2+ releasing procedure. The detection limit (S/N = 3) of the sensor is 0.0315 μg/L with a linear range from 0.1 to 1 μg/L. And the sensor exhibits good recovery with an range from 106 % to 118%, which has great potential for trace Hg2+ determination.
痕量汞离子（Hg2+）的检测对于环境监测和水安全至关重要。在这项工作中，我们研究了基于温控N-辛基吡啶四氟硼酸盐（[OPy][BF4]）分散液液微萃取预富集来检测痕量Hg2+的电化学策略。[OPy][BF4]通过[OPy][BF4]中不饱和N的吸附从水溶液中选择性萃取Hg2+，这增加了Hg2+的浓度并降低了其他干扰离子的浓度。值得注意的是，[OPy][BF4]对Hg2+的吸附会被水溶液削弱。因此，萃取后，沉淀的[OPy][BF4]用包含水和乙腈混合物的缓冲溶液稀释以释放Hg2+，然后通过电化学检测该溶液。水被用来释放被[OPy][BF4]吸附的Hg2+，乙腈在缓冲溶液中用作共溶剂。使用所提出的方法和Hg2+释放程序提高了传感器的灵敏度和抗干扰能力。该传感器的检测限（S/N = 3）为0.0315 μg/L，线性范围为0.1至1 μg/L。并且该传感器具有良好的回收率，范围为106%至118%，在痕量Hg2+测定方面具有巨大潜力。
