一种水溶性Pb^(2+)探针的制备及应用研究

Preparation and application of a water-soluble Pb^(2+) probe

以乙酰丙酮、乙二胺和N-甲基咪唑为原料经醛胺缩合、溴代等合成了单氮杂芳环修饰的水溶性化合物L,通过核磁氢谱、核磁碳谱和红外光谱等手段对其进行表征。利用紫外吸收光谱研究了L与金属离子(Na^+、K^+、Cd^(2+)、Co^(2+)、Cu^(2+)、Mn^(2+)、Ni^(2+)、Zn^(2+)、Pb^2)的配位性能。考察了L与Pb^(2+)的化学配位比以及检出限,并探讨了溶剂、时间和pH对L识别Pb^(2+)性能的影响。结果表明:L的纯水溶液,加入Pb^(2+)30min后,L可以快速地与Pb^(2+)发生1∶1配位,检出限为5×10^(-5) mol/L。在误差允许范围内,L用于模拟实际样品中Pb^(2+)的分析检测,是一种在有机体系和水体系中均可较快速、选择性识别Pb^(2+)的化学探针。

The water-soluble compound L modified by mono-nitrogen heterocyclic ring was synthesized from acetylacetone,ethylenediamine and N-methylimidazole by aldehyde-amine condensation and bromide reaction,and characterized by 1H-NMR,13C-NMR and FT-IR.The coordination properties of L with metal cations (Na^+、K^+、Cd^2+、Co^2+、Cu^2+、Mn^2+、Ni^2+、Zn^2+、Pb^2) were studied by UV absorption spectroscopy.The chemical coordination ratio of L and Pb^2+ and detection limit were investigated,and the effects of solvent,time and pH value on the recognition properties of L to Pb^2+ were discussed.The results showed that aqueous solution of L can quickly coordinated with Pb2+ in a stoichiometric ratio of 1∶1 after 30 minutes,and UV absorption intensity after L and Pb^2+ coordination decreased significantly.The detection limit was 5×10-5mol/L.In the allowable range of error,L can be used to detect Pb^2+ of actual samples.In a word,L is a kind of chemical probe which can be used to identify Pb2+ selectively in organic system and water system.