Abstract：
Water pollution has become a serious issue, and mercury(II) ion (Hg(II)) is highly toxic even at low concentrations. Therefore, Hg(II) concentration should be strictly monitored. This study evaluated pyrazoline compounds as fluorescence chemosensor agents for Hg(II) detection. These compounds were prepared from vanillin via etherification, Claisen-Schmidt, and cyclocondensation reactions, to yield benzothiazole-pyrazoline-styrene hybrid compounds. The hybrid compound without styrene was successfully synthesized in 97.70% yield with limit of detection (LoD) and limit of quantification (LoQ) values of 323.5 and 1078 μM, respectively. Conversely, the hybrid compound was produced in 97.29% yield with the LoD and LoQ values of 8.94 and 29.79 nM, respectively. Further spectroscopic investigations revealed that Hg(II) ions can either chelate with three nitrogen of pyridine, pyrazoline, and benzothiazole structures or two oxygen of vanillin and styrene. Furthermore, the hybrid compound was successfully applied in the direct quantification of Hg(II) ions in tap and underground water samples with a validity of 91.63% and 86.08%, respectively, compared with mercury analyzer measurement. The regeneration of pyrazoline was also easily achieved via the addition of an ethylenediaminetetraacetic acid solution. These findings show the promising application of the benzothiazole-pyrazoline-styrene hybrid compound for Hg(II) monitoring in real environmental samples.
摘要：
水污染已经成为一个严重的问题，汞（II）离子（Hg（II））即使在低浓度下也具有剧毒。因此,应严格监测Hg(II)浓度。这项研究评估了吡唑啉化合物作为用于Hg（II）检测的荧光化学传感器剂。这些化合物是由香草醛通过醚化制备的，Claisen-Schmidt,和环缩合反应，得到苯并噻唑-吡唑啉-苯乙烯杂化化合物。以97.70％的产率成功合成了不含苯乙烯的杂化化合物，检测限（LoD）和定量限（LoQ）值为323.5和1078μM，分别。相反，杂合化合物以97.29%的产率产生，LoD和LoQ值为8.94和29.79nM，分别。进一步的光谱研究表明，Hg（II）离子可以与吡啶的三个氮螯合，吡唑啉,和苯并噻唑结构或两个氧的香草醛和苯乙烯。此外，该杂化化合物已成功应用于自来水和地下水样品中Hg(II)离子的直接定量，有效期分别为91.63%和86.08%，分别,与汞分析仪测量相比。通过加入乙二胺四乙酸溶液也容易实现吡唑啉的再生。这些发现表明，苯并噻唑-吡唑啉-苯乙烯杂化化合物在实际环境样品中的Hg（II）监测中具有广阔的应用前景。
