【作者】 王剑；

【导师】 刘绍璞； 罗红群；

【作者基本信息】 西南大学 ， 分析化学， 2014， 博士

【摘要】 在人们的生产生活中由于重金属的广泛应用,因此含重金属的污染物通过各种途径进入环境,对环境造成严重污染,远远超出了环境对它的承载能力,污染问题日益凸显。重金属的种类很多,检测手段也很多,一些常见的重金属(如铅、铬、汞、镉、锌和铝等)的检测引起了人们的广泛研究,而一些不常见的金属离子相对研究较少,我们选择了钯、银和铜三种重金属离子为研究对象,研究和发展了吸收光谱法、荧光光谱法和共振瑞利散射光谱法测定上述重金属的新体系和新方法,方法简便、快速、灵敏、具有良好的准确度和精密度。1、荧光猝灭法测定Pd(Ⅱ)的研究(1)钯(Ⅱ)对氟喹诺酮类抗生素的荧光猝灭作用及其分析应用研究在弱酸性至近中性介质中,培氟沙星(PEF)、左氧氟沙星(LEV)、洛美沙星(LOM)和氟罗沙星(FLE)等4种氟喹诺酮类抗生素具有相似的激发光谱和荧光光谱,它们的最大激发波长和最大发射波长分别位于276～293nm和442～487nm之间。当它们分别与Pd(Ⅱ)反应形成配合物时,均能导致荧光的猝灭。文中以Pd(II)-PEF体系为例,研究了吸收光谱、荧光光谱的变化,并用量子化学的密度泛函方法(B3LYP)对Pd采用LanL2DZ赝势基组计算,对其他原子采用6-31G(d,p)基组计算,所有计算都采用极化连续介质溶剂化模型(PCM),同时考虑到溶剂的影响,对反应进行了全优化计算。结果表明,此时PEF分子由于质子的转移以两性分子(HL±)型体存在,它与Pd(Ⅱ)反应时Pd(Ⅱ)与2分子的PEF中-COO-和>C=O结合形成两个6元环结构的平面四边形螯合物。根据吸收光谱的变化,温度的升高使荧光猝灭值减小以及高的双分子猝灭常数Kq,表明这类荧光猝灭是由于Pd()与氟喹诺酮抗生素形成配合物产生的一种静态猝灭,荧光猝灭反应具有较高的灵敏度。当用上述四种氟喹诺酮作荧光探针测定Pd(Ⅱ)时的检出限在1.74-3.42ng.mL-1之间,其中以Pd(II)-PEF体系最灵敏,它更适用于Pd(Ⅱ)的荧光测定。当用PEF作荧光探针时,方法有较好的选择性,多数金属离子和无机阴离子具有较大的允许量。方法简便、灵敏、快速具有良好的准确度和精密度,因此可用于某些环境水样中Pd(Ⅱ)的测定,结果与ICP-AES法一致。(2)钯(Ⅱ)和十二烷基苯磺酸钠对氟喹诺酮类抗生素荧光的协同猝灭作用及其分析应用在弱酸性至中性介质中,当Pd(Ⅱ)或十二烷基苯磺酸钠(SDBS)分别与某些FLQs反应时,均能使FLQs的荧光发生不同程度的猝灭,但是当钯(Ⅱ)和SDBS同时与FLQs反应形成三元配合物时,能产生一种增强的荧光协同猝灭作用,可大大提高猝灭反应的灵敏度,其中Pd(II)-PEF-SDBS对Pd(Ⅱ)的检出限可达0.13ng.mL-1,方法有良好的选择性并且简便、快速,用于某些环境水样中钯的测定,得到了满意的结果。文中研究了某些氟喹诺酮类抗生素的荧光光谱特征,Pd(Ⅱ)和SDBS对它们荧光的协同猝灭反应的适宜条件、影响因素、相关的分析化学特性及其分析应用。文中还以Pd(II)-PEF-SDBS体系为例,根据吸收光谱、荧光光谱的变化,以及量子化学的密度泛函法(B3LYP)和极化连续溶剂化模型(PCM),并使用化学计算方法对于FLQs的存在型体、电荷分布及三元配合物的组成和结构进行研究,表明此时FLQs是以HL±的两性型体存在,它与Pd(Ⅱ)反应形成2:1的四配位平面四边形结构的螯合物,而螯合物中两个PEF分子中另一端哌嗪环中带正电荷的质子化的氮原子则分别与2个SDBS结合而形成Pd(II):PEF:SDBS为1:2:2的三元配合物。实验结果还表明正是Pd(Ⅱ)和SDBS与FLQs之间形成的基态三元配合物导致了Pd()或SDBS对于FLQs具有更高的荧光猝灭效率。因此,对于钯的测定也具有更好的分析应用价值。(3)钯(Ⅱ)和溴化十六烷基吡啶对氟喹诺酮类抗生素荧光的协同猝灭作用及其分析应用在弱酸性至中性介质中,当Pd(II)或溴化十六烷基吡啶(CPB)分别与四种氟喹诺酮类抗生素(FLQs)反应时,均能使FLQs的荧光发生不同程度的猝灭,但是当钯(Ⅱ)和CPB同时存在并与FLQs反应形成三元配合物时,产生一种荧光协同猝灭作用,使FLQs的荧光显著降低,协同猝灭的强度大于分别作用时的总和,大大提高猝灭反应的灵敏度,其中Pd(II)-PEF-CPB对Pd(Ⅱ)的检出限可达0.16ng.mL-,方法有良好的选择性并且简便、快速,用于某些环境水样中钯的测定,得到了满意的结果。文中研究了四种氟喹诺酮类抗生素的荧光光谱特征,Pd(Ⅱ)和CPB对它们荧光的协同猝灭反应的适宜条件、影响因素、相关的分析化学特性及其分析应用。文中还以Pd(II)-PEF-CPB体系为例,根据吸收光谱、荧光光谱的变化,以及量子化学的密度泛函法(B3LYP)和极化连续溶剂化模型(PCM),并使用化学计算方法对于FLQs的存在型体、电荷分布及三元配合物的组成和结构进行研究,表明此时FLQs是以HL±的两性型体存在,PEF与CPB通过静电引力形成1：1的复合物,当加入Pd(Ⅱ)后,Pd(Ⅱ)嵌入复合物与-COO-和>C=O螯合形成Pd(II):PEF:CPB为1:2:2的三元配合物,实验结果还表明正是Pd(Ⅱ)和CPB与FLQs之间形成的基态三元配合物导致了Pd(Ⅱ)或CPB对于FLQs具有更高的荧光猝灭效率,猝灭过程为静态猝灭。2、环境中痕量银测定的新方法研究(1)Ag(Ⅰ)与赤藓红体系的吸收和共振瑞利散射光谱及其分析应用研究在4.4-4.6的弱酸性介质中,银(Ⅰ)能与赤藓红反应,形成疏水性的二元离子缔合物。反应产物的体积增大以及分子表面疏水性增强(分子的电荷被中和以及分子中含大量疏水的芳基和烷基骨架)使离子缔合物分子与水相之间形成一种疏水界面,产生一种表面增强的瑞利散射效应,引起共振瑞利散射(RRS)的显著增强,并出现新的发射光谱。据此可借共振瑞利散射发展出测定银的新方法。方法有很高的灵敏度,对银的检出限在0.12ng.mL-1.本文还研究了影响因素和适宜的反应条件,考察了共存物质的影响,表明方法有较好良好的选择性,此方法可用于环境水样中银的测定,得到了较好的结果。而且我们还对相关反应机理进行了讨论。(2)银(Ⅰ)与曙红Y体系的吸收和荧光光谱及其分析应用研究在4.4-4.6的弱酸性介质中,Ag(Ⅰ)能与曙红Y(EY)反应,通过静电引力的作用形成一种二元离子缔合物,结合比为1:1。根据吸收光谱的变化,温度对荧光猝灭的影响以及高的双分子猝灭常数Kq,表明这类荧光猝灭是由于Ag(Ⅰ)直接作用于EY的氧原子上,引起溴原子电荷的显著变化使荧光光谱和吸收光谱发生变化,从而产生了一种静态猝灭过程,荧光猝灭反应具有较高的灵敏度。据此可借荧光猝灭法发展出测定银的新方法。方法有很高的灵敏度,对银的检出限在0.24ng.mL-1.本文研究了荧光猝灭的最佳反应条件和影响因素,实验了共存物质的影响,表明方法有很好的选择性,此方法可用于环境水样中银的测定,测定结果与标准方法结果一致。我们还讨论相关的反应机理。3、环境中痕量铜测定的新方法研究(1)铜(Ⅰ)与赤藓红体系的吸收和共振瑞利散射光谱及其分析应用研究在4.4-4.6的弱酸性介质中,赤藓红以一价阴离子的形式存在,Cu(Ⅱ)被维生素C(VC)还原生成一价铜后,通过静电引力与赤藓红反应,形成疏水性的二元离子缔合物,反应导致共振瑞利散射(RRS)的显著增强,并出现新的发射光谱。由于RRS位于产物的吸收带中,反应产物的体积增大,极化率的降低以及分子表面疏水性增强使离子缔合物分子与水相之间形成一种疏水界面,产生一种表面增强的瑞利散射效应。据此可借共振瑞利散射技术可以建立一种测定铜离子的新方法。方法有很高的灵敏度,对铜的检出限在0.58ng.mL-1.本文研究了RRS适宜的反应条件和影响因素,实验了共存物质的影响,表明方法有较好的选择性,当以方法测定环境水样中Cu(Ⅱ)时,测定结果与标准方法一致,得到了较好的结果。同时我们还对相关反应机理进行了讨论。(2)铜(Ⅰ)与曙红Y体系的吸收和荧光光谱及其分析应用研究我们的研究发现,在4.4～4.6的弱酸性介质中,Cu(II)被维生素C(VC)还原生成一价Cu,Cu(I)与曙红Y(EY)反应,形成二元离子缔合物,导致EY的荧光强度显著猝灭。根据吸收光谱的变化,温度对荧光猝灭的影响以及高的双分子猝灭常数Kq,可以推断该反应导致的荧光猝灭是由于Cu(I)与EY形成了一种二元离子缔合物,从而产生的一种静态猝灭过程,荧光猝灭反应具有较高的灵敏度。据此建立了以EY为荧光探针,荧光猝灭法测定铜的新方法,对铜的检出限为3.7ng.mL-1.本文研究了适宜的反应条件和影响因素,考察了共存物质的影响,表明方法有较好的选择性,此方法可用于环境水样中铜的测定,测定结果与标准方法进行了比较,结果一致,另外我们还对相关反应机理进行了讨论。更多还原

【Abstract】 Heavy metals have been used widely in the production and live of people, the heavy metals pollution become more and more serious with them into the environment through various ways, it is far beyond the carrying capacity of the environment, the problem of pollution is becoming more and more highlighted. There are many types of heavy metal, and their detection methods are different, the determinations of some common heavy metals including lead, chromium, mercury, cadmium, zinc and aluminum were extensively studied by people, and some of the unusual metal ions was less. Taking palladium, silver and Copper as research objects, we have studied and developed new systems and methods for the determination of the above heavy metal in environment using spectrophotometry, fluorescence and Resonance Rayleigh scattering techniques. The methods are rapid, simple and reliable.1Study on the fluorescence quenching methods for determination of Pd (Ⅱ)(1) The fluorescence quenching of fluoroquinolones by palladium(II) and its analytical applicationIn a weakly acidic or neutral medium, fluoroquinolones (FLQs) such as pefloxacin (PEF), levofloxacin (LEV), lomefloxacin (LOM) and fleroxacin (FLE), have similar fluorescence spectral characteristics. Their fluorescence intensities could be significantly quenched by palladium. In this work, taking Pd(II)-PEF system as an example, the absorption and fluorescence spectral changes were investigated. In addition, the density functional theory (DFT) methods (B3LYP) was performed to optimize those compounds. A Pd (II) molecule bond two PEF molecules to form a square planar chelate with two six-membered rings, and the quenching effect of Pd(II) on PEF fluorescence is a single static quenching event. The detection limits were in the range of1.74-3.42ng/mL using the above four FLQs. Most of metal ions and inorganic anions have no interference. The method was applied to the determination of Pd(II) in environmental water.(2) Synergistic fluorescence quenching of quinolone antibiotics by palladium(II) and sodium dodecyl benzene sulfonate and the analytical applicationIn weakly acidic and neutral media, palladium (II) or sodium dodecyl benzene sulfonate (SDBS) can result in fluorescence quenching of quinolone antibiotics (FLQs) to some different extents. When Pd(II) react with SDBS and FLQs to form ternary complexes, a enhanced fluorescence quenching of FLQs could be observed. This synergistic fluorescence quenching reaction has high sensitivity for Pd(II) and the detection limits could reach to0.13ng.mL-1. Based on this, a rapid, simple and reliable method for determination of Pd(II) in aqueous samples was established. The spectral characteristics of the fluorescence spectra were investigated. The optimum reaction conditions of the method were tested. The interaction between Pd(II), FLQs and SDBS was investigated by absorption spectra, fluorescence spectra, and was calculated by quantum chemical using density function theory B3LYP under polarizable continuum model (PCM). The pefloxacin (PEF) molecules exist as zwitter-ion of HL±reacting with Pd(II) to form2:1plane quadridentate chelates, which further binds two SDBS molecules to form ternary complexes (Pd(II):PEF:SDBS=1:2:2). The ternary complexes resulted in higher fluorescence quenching efficiency and enhanced the sensitivity for determination of Pd(II).(3) Synergistic fluorescence quenching of quinolone antibiotics by palladium(II) and Hexadecyl pyridine bromide and the analytical applicationIn weakly acidic and neutral media, palladium (II) or Hexadecyl pyridine bromide (CPB) can result in fluorescence quenching of quinolone antibiotics (FLQs) to some different extents. When Pd(II) react with CPB and FLQs to form ternary complexes, a enhanced fluorescence quenching of FLQs could be observed. This synergistic fluorescence quenching reaction has high sensitivity for Pd(II) and the detection limits could reach to0.16ng.mL-1. Based on this, a rapid, simple and reliable method for determination of Pd(II) in aqueous samples was established. The spectral characteristics of the fluorescence spectra were investigated. The optimum reaction conditions of the method were tested. The interaction between Pd(II), FLQs and CPB was investigated by absorption spectra, fluorescence spectra, and was calculated by quantum chemical using density function theory B3LYP under polarizable continuum model (PCM). The ternary complexes resulted in higher fluorescence quenching efficiency and enhanced the sensitivity for determination of Pd(II).2Study on new methods for the determination of silver in environment(1) Study on the Interaction between Ag(I) and Erythrosin by Absorption and Resonance Rayleigh Scattering SpectraIn weakly acidic and neutral media, Erythrosin (Ery) can react with Ag(I) to form ion-association complex. As a result, the increase of molecular volum and hydrophobic interface forms are advantageous to enhancement of RRS intensities, and a new RRS spectrum appeared. A sensitive, simple and new method for the determination of Ag(I) by using Ery as the probe has been developed. The detection limits for Ag(I) was0.12ng.mL-1for RRS method. The spectral characteristics of the RRS spectra were investigated. The optimum reaction conditions of the method were tested. The method was applied to the determination of Ag(I) in environmental water, and the result was fine. In addition, the reaction mechanism was discussed.(2) Study on the Interaction between Ag(I) and Eosin Y by Absorption and fluorescence SpectraIn weakly acidic and neutral media, Eosin Y (EY) can react with Ag(I) to form ion-association complex. As a result, the complex could quench the fluorescence of EY. Based on change of absorption spectra, increase of temperature resulting in fluorescence quenching decrease and high apparent quenching constants, these indicated the quenching effect was a static quenching event. We developed a new method for the determination of Ag(I), the detection limits was0.24ng.mL-1. The optimum reaction conditions of the method were tested. The method was applied to the determination of Ag(I) in environmental water, and the result was fine. In addition, the reaction mechanism was discussed.3Study on new methods for the determination of copper in environment(1) Study on the interaction Cu(I) and Erythrosin by Absorption and Resonance Rayleigh Scattering SpectraIn weakly acidic and neutral media, Cu(II) is redox to Cu(I) by vitamin C, Erythrosin (Ery) can react with Cu(I) to form ion-association complex. As a result, the increase of molecular volum and hydrophobic interface forms are advantageous to enhancement of RRS intensities, and a new RRS spectrum appeared. A sensitive, simple and new method for the determination of Cu(I) by using Ery as the probe has been developed. The detection limits for Cu(II) was0.58ng.mL-1for RRS method. The spectral characteristics of the RRS spectra were investigated. The optimum reaction conditions of the method were tested. The method was applied to the determination of Ag(I) in environmental water, and the result was fine. In addition, the reaction mechanism was discussed.(2) Study on the Interaction Cu(I) and Eosin Y by Absorption and fluorescence SpectraIn weakly acidic and neutral media, Cu(II) is redox to Cu(I) by vitamin C, Eosin Y (EY) can react with Cu(I) to form ion-association complex. As a result, the complex could quench the fluorescence of EY. Based on change of absorption spectra, increase of temperature resulting in fluorescence quenching decrease and high apparent quenching constants, these indicated the quenching effect was a static quenching event. We developed a new method for the determination of Cu(II), the detection limits was3.7ng.mL-1. The optimum reaction conditions of the method were tested. The method was applied to the determination of Cu(II) in environmental water, and the result was fine. In addition, the reaction mechanism was discussed.更多还原