【作者】 许文菊；

【导师】 袁若；

【作者基本信息】 西南大学 ， 分析化学， 2009， 博士

【摘要】 电位分析法是一种经典的电化学分析方法。而直接电位分析法是两大电位分析方法之一,又被称为离子选择性电极法。即利用离子选择性电极（又叫膜电极）把被测离子的活度或浓度表现为电极电位而实现分析测定。离子选择性电极是一类电化学传感器,又是一种指示电极,它所指示的电极电位值与相应离子活度的关系符合Nernst方程。其分析的实质是当电池体系接近于零电流条件时,测定指示电极的平衡电位,而求得待测离子的浓度。理想的离子选择性电极应该能够快速、稳定地响应被分析离子。与其它分析方法相比,它具有简单方便、成本低廉,分析速度快,测量范围广,灵敏度高等许多优点；是近年来迅速发展的一种快速分析方法。离子选择性电极法的研究核心是开发设计与合成对目标分析物具有特殊识别作用的配合物,并将其运用于电极的敏感载体。当将敏感载体固着在聚氯乙烯（PVC）基体时,电极的制备更简单,使用更方便,性能更优良。截止目前,许多电化学传感器工作者从电极载体入手,先后将各种具有特殊功能的新型配合物引入到PVC膜中,并己成功构建了多种阴、阳离子选择性PVC膜电极。如今,各种新型配合物的开发并应用于离子选择性电极载体,构建新的目标分析物测量体系正呈现活跃的态势。人们正试图寻求各种途径和方法来改善离子选择性PVC膜电极的性能,改进测量体系的功能和用途。本研究工作根据电极敏感载体的选择原则,合成了具有特殊结构和特殊性能并能与特定阴离子或阳离子选择性结合的金属酞菁衍生物及Schiff碱化合物,将这些配合物运用于PVC膜电极的敏感载体,成功制备出了几种阴离子和阳离子选择性PVC膜电极;并采用电化学方法和手段,对这些离子选择性电极进行各项性能表征,构建出了检测目标分析物的新的分析测试体系。全文包括正篇和副篇两部分:正篇:PVC膜阴离子选择性电极的构建及表征。（一）利用酞菁氧钛（Ⅳ）配合物（PcTiO）为载体成功制备了优先响应I^-的选择性PVC膜电极。通过改变增塑剂、载体含量、离子添加剂等使电极膜的电位响应性能得到优化。经测试含最佳膜组成的电极的基本电化学性能,发现电极对I^-呈现出优先的电位识别过程和良好的电位分析性能。其在1.0×10^-1-9.2×10^-7 mol·L^-1范围内呈现出斜率为-58.9 mV·dec^-1的near-Nernstian线性响应,检测下限为8.5×10^-7 mol·L^-1;选择性序列为:I^-＞SCN^＞NO₂^-＞Br^-＞ClO₄^-＞C₂O₄^2-＞SO₃^2-＞F^-＞NO₃^-＞Ac^-＞Cl^-＞SO₄^2-＞H₂PO₄^-。目标电极对I^-呈现的高灵敏度和高选择性可能来源于载体中心金属Ti（Ⅳ）与I^-在轴向进行了可逆配位;而优先的电位响应是基于载体PcTiO携带溶液中的I^-有效通过PVC膜相而产生。（二）研究了酞菁锌（Ⅱ）（ZnPc）和酞菁锰（Ⅲ）（MnPc）为载体的PVC膜电极的电位响应。结果表明,基于ZnPc的膜电极对SCN^-呈现出斜率为-58.1 mV·dec^-1的near-Nernstian优先电位响应,其线性范围为1.0×10^-1-1.0×10^-6mol·L^-1,检测下限为7.5×10^-7 mol·L^-1。测试不含添加剂的电极B和含阳离子添加剂HTAB的电极G的电位响应特性,发现HTAB的加入虽然改善了电极的灵敏度、线性范围及检测下限,但其选择性却有所降低。电极B呈现的选择性序列为:SCN^-＞Sal^-＞I^-＞ClO₄^-＞Br^-＞Cl^-＞NO₃^-＞NO₂^-＞H₂PO₄^-＞SO₄^2-。ZnPc载体电极对SCN^-显示的优良电位响应可能来源于载体ZnPc中心金属Zn（Ⅱ）与溶液中的SCN^-进行了可逆配位。（三）研究了以2,9,16,23-四硝基酞菁铜（Ⅱ）（CuTNPc）和2,9,16,23-四胺基酞菁铜（Ⅱ）（CuTAPc）为载体的PVC膜电极的电位响应。结果表明,含推电子基团（NH₂）的CuTAPc为载体的电极对Sal^-呈现出斜率为-49.5 mV·dec^-1的sub-Nernstian响应;而含吸电子基团·（NO₂）的CuTNPc为载体的膜电极对Sal^-具有优先的选择性和良好的电位响应性能,这可能是由于吸电子基团NO₂的存在使得CuTNPc中心金属Cu（Ⅱ）附近呈现低电荷密度状态而有利于Sal^-与之配位。同时,阴离子添加剂NaTPB的加入显著改善了CuTNPc载体电极的电位响应性能和选择性;该电极的near-Nernstian斜率为-59.8 mV·dec^-1,线性范围为1.0×10^-1-9.0×10^-7 mol·L^-1,检测下限为7.2×10^-7 mol·L^-1;呈现的选择性为:Sal^-＞SCN^-＞I^-＞ClO₄^-＞NO₃^-＞Br^-＞NO₂^-＞Benzoate＞Cl^-＞OAc^-＞SO₄^2-＞C₂O₄^2-＞Lactate＞Citrate。根据离子位点对电极选择性影响的理论模型,CuTNPc载体电极可能是基于电荷载体作用机理。（四）测试了基于酞菁铝（Ⅲ）（AlPc）为敏感载体的NO₂^-选择性PVC膜电极的电位响应。具有最佳膜组成含阳离子添加剂TOMAC的电极在1.0×10^-1-1.5×10^-6 mol·L^-1约五个数量级范围呈现near-Nernstian线性响应,斜率为-58.3 mV·dec^-1,检测下限为9.5×10^-7 mol·L^-1;该电极的选择性为:NO₂^-＞SCN^-＞Sal^-＞ClO₄^-＞I^-＞NO₃^-＞Cl^-＞OAc^-＞Br^-＞SO₄^2-＞H₂PO₄^-。而阴离子添加剂NaTPB的加入却使得电极的电位响应显著恶化。（五）研究了以N,N’-双（邻羟基苯亚甲基）-1,2-双（p-氨基苯氧基）-乙烷（BBAP）合Cu（Ⅱ）、Mn（Ⅲ）和Zn（Ⅱ）（CuBBAP、MnBBAP和ZnBBAP）三种Schiff碱金属配合物为载体的PVC膜电极的电位响应。结果表明,具有平面型结构的CuBBAP为载体的电极对I^-具有优先电位选择性:I^-＞SCN^-＞ClO₄^-＞NO₂^＞H₂PO₄^-＞NO₃^-＞SO₄^2-＞Br^-＞Cl^-。具有最佳膜组成的电极在1.0×10^-1-8.2×10^-7mol·L^-1范围呈现斜率为-58.8 mV·dec^-1的near-Nernstian线性响应,检测下限为5.3×10^-7 mol·L^-1。而具有三角双锥结构的MnBBAP和四面体结构的ZnBBAP为载体的电极均未显示出良好的I^-优先响应行为。表明载体空间化学环境的差异可能对三种载体电极的电位响应起着重要作用。副篇:PVC膜阳离子选择性电极的构建及表征。（一）探讨了基于简单Schiff碱N,N’-双（2-苯羟基）-1,3-二氨基丙烷（BHDP）、N,N’-双（2-苯羟基）-2,2-二甲基-1,3-二氨基丙烷（BHDDP）和N,N’-双（2-苯羟基）-1,4-二氨基丁烷（BHDB）为中性载体的PVC膜电极的电位响应。实验观察到基于BHDP和BHDB为载体的膜电极对Ag^-呈现出优先的选择性识别和稳定的near-Nernstian电位分析特性。各自的斜率为58.7和58.1mV·dec^-1,线性范围近五个数量级,检测下限均为1.0μmol·L^-1;呈现的选择性分别为:Ag⁺＞Cu²⁺＞Pb²⁺＞Co²⁺＞Hg²⁺＞Cr³⁺＞Al³⁺＞Mg²⁺＞K⁺＞Cd²⁺＞Zn²⁺＞Ba²⁺＞NH₄⁺＞Ca²⁺＞Mn²⁺＞Sr²⁺＞Bi³⁺和Ag⁺＞Cu²⁺＞pb²⁺＞Mg²⁺＞Hg²⁺＞Cr³⁺＞Al³⁺＞K⁺＞Cd³⁺＞Zn²⁺＞Co²⁺＞Ba²⁺＞NH₄⁺＞Ca²⁺＞Mn²⁺＞Bi³⁺＞Sr²⁺。而基于BHDDP为载体的电极却显示出低灵敏度的Ag⁺响应特性,斜率为53.7 mV·dec^-1。这种差异可能与BHDP和BHDB具有与Ag⁺匹配的空间构型有关。（二）探究了以含N和O受体原子的两种Schiff碱（LⅠ和LⅡ）为中性载体制备的PVC膜电极的电位响应。结果表明,LⅠ载体电极对Pb²⁺仅呈现出斜率为34.1 mV·dec^-1的super-Nernstian电位响应。而基于LⅡ为载体的电极在Pb（NO₃）₂溶液和部分非水介质中均呈现出优先的Pb²⁺选择性识别过程和明显的near-Nernstian线性响应;电极在1.0×10^-1-1.7×10^-6mol·L^-1浓度范围给出的斜率为29.5 mV·dec^-1,检测下限为1.0μmol·L^-1;其电位选择性序列为:pb²⁺＞Cd²⁺＞Mg²⁺＞Cr³⁺＞Al³⁺＞Hg²⁺＞Zn²⁺＞Co²⁺＞Ca³⁺＞Ba²⁺＞Cu²⁺＞NH₄⁺＞Ag⁺＞Bi³⁺＞K⁺。更多还原

【Abstract】 Potentiometry is a classical electrochemical analysis method. Direct potentiometry, one of the two potentiometry methods, is called ion-selective electrode （ISE） method, which carrys out the quantitative analysis by converting the live degree or concentration of ion into potential signal by using ion-selective electrode （i.e. membrane electrode）. ISE is a sort of chemistry sensors also is a kind of indicator electrodes. The relationship between the potential value indicated by an ISE and the live degree of the corresponding ion is accordance with Nernst-equation. The essential of this method is to determine equilibrium potential indicated by the indicator electrode when the cell system is controlled under zero-current state, and further to calculate the concentration of the analyte ion according to Nernst-equation and the obtained potential value. A perfect ISE should be able to rapidly and steadily respond the analyte. Compared with other analysis methods, ISE method owns such many unique advantages as simple equipment, convenient operation, cheap cost, fast analysis, wide linear range, high sensitivity and etc. It’s a fast analysis method developed rapidly in near years.The research key of ISE is to exploit, design and synthesize certain compound which can identify particularly a target analyte ion, and to use it as the sensing carrier of ISE. Immobiling the sensing carrier in polyvinyl chloride （PVC） matrix makes ISE be prepared easily, used conveniently and performed perfectly. Up to now, many sensor researchers started with electrode carrier, introduced successively novel compounds with especial function into PVC membranes and have constructed successfully many anion- and cation-selective PVC membrane electrode. At present, design and synthesis of many novel compounds, use them as the carriers of ISEs and establishing new measurement system for a target analyte are showing active situation. The researchers have been seeking all kinds of approaches and means to improve the potential response performance of ISE and the function and purpose of analysis system by ISE. In this work, according to the principle of selecting electrode carrier, metallophthalocyanine derivatives and Schiff bases with special structure and performance which can selectively interact with target anion or cation were synthesized and used as the sensing carriers of PVC membrane ISEs. As a result, certain anion- and cation-selective PVC membrane electrodes were fabricated successfully. Electrochemistry methods and means were used to characterize the potential performance of the resultant ISEs, and the new analysis system for a target analyte was established. The dissertation consists of primary section and secondary section:Primary section: Fabrication and characterization for PVC membrane anion ISEs.（一） An I^-selective PVC membrane electrode based on phthalocyaninatotitanium（Ⅳ） oxide （PcTiO） complex was prepared successfully. The potential response of the electrode was optimized by changing the nature of plasticizers, the concentration of carrier, and ion additives. The basic electrochemistry characteristics investigated for the optimized membrane suggested that the resulting electrode to I^- showed selectively identifying process and good potential analysis performance in a linear range of 1.0×10^-1 - 9.2×10^-7 mol·L^-1 with a slope of -58.9 mV·dec^-1 and a detection limit of 8.5×10^-7 mol·L^-1. The selectivity sequence was: I^-＞SCN^-＞NO₂^-＞Br^-＞ClO₄^-＞C₂O₄^2-＞SO₃^2-＞F^-＞NO₃^-＞Ac^-＞Cl^-＞SO₄^2-＞H₂PO₄^-. The high sensitivity and selectivity showed by the proposed electrode to I^- may be originated from the reversible interaction between the central metal Ti（Ⅳ） and I^- at axial direction. And the preferential potential response might be resulted from the effective process of I^- crossing the PVC membrane taken by the carrier PcTiO.（二） The potential response of PVC membrane electrodes based on metallophthalocyanines of Zn（Ⅱ） and Mn（Ⅲ） （ZnPc and MnPc） as carriers was investigated. The observations suggested that the electrode based on ZnPc showed selective near-Nernstian potential response to SCN in a linear range of 1.0×10^-1 - 1.0×10^-6mol·L^-1 with a slope of -58.1 mV·dec^-1 and a detection limit of 7.5×10^-7 mol·L^-1. The potential response difference between the electrode B without additive and the electrode G with cationic additive HTAB indicated that the presence of HTAB improved the senstivity, linear range and detection limit, but resulted in the decrease of the selectivity. The selectivity sequence for the electrode B was: SCN^-＞Sal^-＞I^-＞ClO₄^-＞Br^-＞Cl^-＞NO₃^-＞NO₂^-＞H₂PO₄^-＞SO₄^2-. The good potential response showed by ZnPc-based electrode to SCN^- may be originated from the reversible interaction between central metal Zn（Ⅱ） and SCN^-.（三） The potential response of the PVC membrane electrodes baed on two metallophthalocyaninederivatives, 2,9,16,23-copper（Ⅱ）-tetra-nitro phthalocyanine （CuTNPc） and 2,9,16,23-copper （Ⅱ）-tetra-amino phthalocyanine （CuTAPc） as carriers were studied. The result obtained indicated that the electrode based on CuTAPc with electron-repulsive showed sub-Nernstian potential response of to Sal^- with a slope of -49.5 mV·dec^-1. And the electrode incorporating CuTNPc with electron-withdrawing groups （NO₂） exhibited preferential selectivity and good potential response characteristics for Sal^- which may be suggested by that, in the presence of electron-withdrawing groups NO₂ in CuTNPc, the low electron density in the vicinity of central Cu（Ⅱ） atom was favorable for the coordination of Sal^-. The addition of anion additive NaTPB improved greatly the potential response characteristics and the selectivity. The resulting electrode gave a near-Nemstian solpe of -59.8 mV·dec^-1 with a linear range of 1.0×10^-1 - 9.0×10^-7 mol·L^-1 and a detection limit of 7.2×10^-7 mol·L^-1. Its selectivity sequence was: Sal^-＞SCN^-＞I^-＞ClO₄^-＞NO₃^-＞Br^-＞NO₂^-＞Benzoate＞Cl^-＞OAc^-＞SO₄^-2＞C₂O₄^-2＞Lactate＞Citrate, According to the theoretical models that predict the effects of ion sites on the selectivity, CuTNPc may act on the basis of a charged carrier mechanism.（四） The potential response of a PVC membrane NO₂^- -selective electrode based on a aluminum（Ⅲ）-phthalcyanine （AlPc） as sensing carrier was investigated. The observations indicated that the electrode with the optimized membrane containing cationic additive TOMAC exhibited near-Nernstian linear response in five orders of magnitude with a slope of -58.3 mV·dec^-1 and a detection limit of 9.5×10^-7 mol·L^-1. The selectivity sequece obtained was: NO₂^-＞SCN^-＞Sal^-＞ClO₄^-＞I^-＞NO₃^-＞Cl^-＞OAc^-＞Br^-＞SO₄^2-＞H₂PO₄^-. But the addition of anionic additive NaTPB intensively deteriorated the potential response of the electrode.（五） The potential response of the PVC membrane electrodes based on three Schiff base metal complexes Cu（Ⅱ）, Mn（Ⅲ） and Zn（Ⅱ） of N,N’-bis（salicylidene）-1,2-bis（p-aminophenoxy）-ethane （BBAP） （CuBBAP, MnBBAP and ZnBBAP） as carriers was investigated. The observation indicated that the electrode based on CuBBAP with sequare-planar structure displayed a preferential selectivity to I^-: I^-＞SaN^-＞ClO₄^-＞NO₂^-＞H₂PO₄^-＞NO₃^-＞SO₄^2-＞Br^-＞Cl^-. The electrode doped with the optimized membrane showed near-Nernstian linear response in a range of 1.0×10^-1 -8.2×10^-7mol·L^-1 with a slope of -58.8 mV·dec^-1 and a detection limit of 5.3×10^-7 mol·L^-1. But the electrodes based on MnBBAP with trigonal-bipyramidal and ZnBBAP with tetrahedral structure exhibited no good response behavior to I^-. The potential response difference between them may imply that the steric chemical environment has an important influence on their performance.Secondary section: Fabrication and characterization for PVC membrane cation ISEs.（一） The potential response of the PVC membrane electrodes based on simple Schiff bases, N,N’-bis（2-hydroxybenzyl）-1,3-diaminopropane（BHDP）, N,N’-bis（2-hydroxybenzyl）-2,2-dimethyl-1,3-diaminopropane（BHDDP）, and N,N’-bis（2-hydroxybenzyl）-1,4-diaminobutane（BHDB）, as neutral carriers was discussed. The experiments observed indicated that the resulting electrodes based on BHDP and BHDB showed preferential selectivity recognition and stable near-Nernstian characteristics toward Ag⁺. The two electrodes gave respectively a slope of 58.7 and 58.1 mV·dec^-1 in five orders of magnitude with a detection limit of 1.0 umol·L^-1, and the selectivity sequence was: Ag⁺＞Cu²⁺＞Pb²⁺＞Co²⁺＞Hg²⁺＞Cr³⁺＞Al³⁺＞Mg²⁺K⁺＞Cd²⁺＞Zn²⁺＞Ba²⁺＞NH₄⁺＞Ca²⁺＞Mn²⁺＞Sr²⁺＞Bi³⁺ and Ag⁺＞Cu²⁺＞Pb²⁺＞Mg²⁺＞Hg²⁺＞Cr³⁺＞Al³⁺>K⁺＞Cd²⁺＞Zn²⁺＞Co²⁺＞Ba²⁺＞NH₄⁺＞Ca²⁺＞Mn²⁺＞Bi³⁺＞Sr²⁺, respectively. And relatively low sensitivity was observed for the electrode based on BHDDP with a slope of 53.7 mV·dec^-1. The difference between the electrodes may be attributed to the steric structure of BHDP and BHDB suitable for Ag⁺.（二） The potential response of the PVC membrane electrodes incorporating two Schiff bases（LⅠand LⅡ） with N and O donor atoms as neutral carriers was investigated. The observations indicated that super-Nernstian potential response of 34.1 mV·dec^-1 slope for the electrode based on LⅠto Pb²⁺was observed. But the resulting electrode based on LⅡshowed selective potential recognition and obvious near-Nernstian response to Pb²⁺ in Pb（NO₃）₂ solution or partially non-aqueous media, which gave a selectivity sequence of Pb²⁺＞Cd²⁺＞Mg²⁺＞Cr³⁺＞Al³⁺＞Hg²⁺＞Zn²⁺＞Co²⁺＞Ca²⁺＞Ba²⁺＞Cu²⁺＞NH₄⁺＞Ag⁺＞Bi³⁺K⁺ in a linear range of 1.0×10^-1- 1.7×10^-6 mol·L^-1 with a slope of 29.5 mV·dec^-1 and a detection limit of 1.0μmol·L^-1.更多还原