应用化学

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汞(Ⅱ)-邻菲啰啉-刚果红缔合体系的共振瑞利散射和共振非线性散射光谱及分析应用

孙谦,杨迎春*,叶芝祥,张林   

  1. (成都信息工程学院资源环境学院,大气环境模拟与污染控制四川省高校重点实验室 成都 610225)
  • 收稿日期:2012-06-15 修回日期:2012-10-10 出版日期:2013-04-10 发布日期:2013-04-10
  • 通讯作者: 杨迎春,教授; Tel:028-85966941; Fax:028-85966089; E-mail:yangyingchun@cuit.edu.cn; 研究方向:环境监测,环境化学
  • 基金资助:
    四川省教育厅重点基金(09ZAO16)成都信息工程学院科研人才基金(J201215)资助项目

Resonance Rayleigh Scattering and Resonance nonlinear Scattering Spectra of Hg(Ⅱ)-phen-CR Systems and Their Analytical Application

SUN Qian, YANG Yingchun*, YE Zhixiang, ZHANG Lin   

  1. (Department of Resources and Environment,Air Environmental Modeling and Pollution Controlling
    Key Laboratory of Sichuan Higher Education Institutes,Chengdu University of
    Information Technology,Chengdu 610225,China)
  • Received:2012-06-15 Revised:2012-10-10 Published:2013-04-10 Online:2013-04-10
  • Contact: Yang yingchun

摘要: 在pH=9.0的弱碱性环境中,Hg2+与邻菲啰啉(phen)反应形成无色螯合物[Hg(phen)3]2+,再与刚果红(CR)反应,形成三元离子缔合物Hg(phen)3CR,其摩尔比为1∶1。 此时引起共振瑞利散射(RRS)、二级散射(SOS)和倍频散射(FDS)光谱显著增强,最大的散射波长分别位于578 nm(RRS法)、612 nm(SOS法)和352 nm(FDS法)。 在一定条件下,散射增强(ΔI)与Hg2+浓度呈良好的线性关系,检出限分别为2.32 μg/L(RRS法)、3.20 μg/L(SOS法)和1.56 μg/L(FDS法),考察了最佳实验条件和影响因素,表明本方法具有良好的选择性,并以RRS法为例研究了共存物质的影响。 据此建立了灵敏度高、选择性好、快速准确测定Hg2+的光散射新方法,该方法用于环境水样中Hg2+的测定取得满意结果。 并对RRS增强的原因和反应机理进行了讨论。

关键词: 共振瑞利散射, 二级散射, 倍频散射, 汞(Ⅱ), 邻菲啰啉, 刚果红

Abstract: In alkaline medium of pH=9.0, Hg2+ reacts with phenanthroline(phen) to form a colorless chelate [Hg(phen)3]2+, which further reacts with Congo red(CR) to form 1∶1 ion-association complex. As a result, new peaks appear in the spectra of resonance Rayleigh scattering(RRS), second order scattering(SOS) and frequency doubling scattering(FDS), and their intensities are enhanced greatly. The maximum peaks of RRS, SOS and FDS are located at 378 nm, 612 nm and 352 nm, respectively. The enhanced RRS, SOS and FDS intensities are directly proportional to the concentrations of Hg2+. These methods have very high sensitivities and good selectivities, and the detection limits are 2.32 μg/L for RRS, 3.20 μg/L for SOS, 1.56 μg/L for FDS, respectively. In addition, the influencing factors and the effects of coexisting substances of the reaction were examined by RRS under optimum conditions. The results show that this method has a good selectivity. Therefore, a new method has been developed to determine trace amounts of Hg2+. The reasons for RRS enhancement of the system and reaction mechanism have been investigated.

Key words: resonance rayleigh-scattering, Second-Order scattering (SOS), frequence doubling scattering, Mercury(Ⅱ), phenanthroline, Congo red

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