离子交换树脂在分析化学中的应用

简要评述了离子交换树脂在分析化学中的应用。包括离子交换树脂预富集技术从稀溶液中浓缩痕量离子,离子交换树脂相分光光度法测定微量离子,离子色谱在无机分析中的应用,以及离子交换树脂在有机分析与生化分析中的应用。     

微波浓缩/离子色谱法测定印刷电路板表面的7种痕量无机阴离子

建立了印刷电路板上7种痕量无机阴离子(F-、NO-2、Cl-、Br-、NO-3、PO3-4、SO2-4)的微波浓缩/离子色谱测定方法.印刷电路板样品经纯水提取,微波浓缩后,在Ionpac AS23分析柱上,以4.5 mmol/LNa2 CO3+0.8 mmol/L NaHCO3为淋洗液,流速为1.0 mL/min.结果...     

离子色谱法测定电厂凝水处理模拟系统高纯水中的全铁

研究了用离子色谱法测定电厂凝水处理系统中高纯水中全铁的方法，用过硫酸铵将水样中的铁全部转化成Fe^3 ，再用浓缩柱浓缩样品，离子色谱法分析Fe^3 ，得到全铁的含量，检出限为1μg/L。     

THE REVIEW OF MIEX(R) IN DRINKING WATER TREATMENT

磁性树脂(MIEX(R))作为一种新型强碱型阴离子交换树脂能够通过离子交换作用去除水体中天然有机物和无机阴离子.与传统离子交换树脂相比,MIEX(R)具有吸附速率快,易再生等优势,正逐渐应用于饮用水净化与深度处理领域.论文综述了MIEX(R)的主要理化特性；在水处理中的应用效果,包括对目标污染物的去除以及受溶液pH值,温度,竞争吸附离子等的影响;阐述了MIEX(R)与混凝、活性炭、膜滤等常规处理工艺集成的可行性及优势；最后对MIEX(R)和磁性树脂技术在国内饮用水处理应用过程中面临的问题提出了建议和展望.     

冰冻浓缩技术的应用

冰冻浓缩技术是依据在正常冰冻中杂质在液-固两相中分配不同而达到分离浓缩的一种方法.本文将含金属离子的稀溶液或自来水放入冰箱速冻层进行冰冻,使溶液部分冻冰,考察了冰冻后留在水相中金属离子量,试验证明,稀溶液中的金属离子,或自来水中的痕量金属离子都能定量浓缩干水相,这一分离浓缩技术,溶液中溶质的价态和状态没有受到破坏,由于不加入试剂、不加热煮沸,又在密闭系统中进行,所以,将污染和损失减少到最低限度,这是一种无破坏无污染的分离浓缩技术,可作多元素的同时浓缩测定和实验室制备少量纯冰纯水用,对研究稀溶液中溶质的价态和状态提供了一种有效的浓缩技术.     

Degradation and Removal of Suifadiazine from Waters by a Novel Polymer-supported Hydrous Manganese Dioxide(HMO)

以大孔强碱阴离子交换树脂D201为载体,采用离子交换和氧化还原方法制备了一种新型树脂基水合锰氧化物材料HMO-201.考察了不同pH、离子强度和溶解性有机质(DOM)含量条件下,该材料对水体中磺胺嘧啶(SD)的去除能力.HPLC-MS分析表明,SD的高效去除是通过HMO-201的降解而非吸附方式实现的.实验结果表明,pH为1.0时HMO-201在120 min内对0.01 mmol/L SD的去除效率为99.9％,反应符合表观一级动力学模型；体系的离子强度和DOM含量变化对SD的去除效率均无显著影响.模拟环境离子强度和DOM浓度,连续10批次实验中SD废水的去除效率在240 min内均大于99％；HMO-201的柱动态降解装置连续处理SD溶液2000床体积,依然未检出SD.表明HMO-201材料具有较稳定的重复利用性,对环境中普遍存在的磺胺类抗生素药物具有着高效的降解去除效果,具有广泛的应用前景.     

新型树脂基水合锰氧化物对水体中磺胺嘧啶的降解去除

以大孔强碱阴离子交换树脂D201为载体, 采用离子交换和氧化还原方法制备了一种新型树脂基水合锰氧化物材料HMO-201. 考察了不同pH、 离子强度和溶解性有机质(DOM)含量条件下, 该材料对水体中磺胺嘧啶(SD)的去除能力. HPLC-MS分析表明, SD的高效去除是通过HMO-201的降解而非吸附方式实现的. 实验结果表明, pH为1.0时HMO-201在120 min内对0.01 mmol/L SD的去除效率为99.9%, 反应符合表观一级动力学模型; 体系的离子强度和DOM含量变化对SD的去除效率均无显著影响. 模拟环境离子强度和DOM浓度, 连续10批次实验中SD废水的去除效率在240 min内均大于99%; HMO-201的柱动态降解装置连续处理SD溶液2000床体积, 依然未检出SD. 表明HMO-201材料具有较稳定的重复利用性, 对环境中普遍存在的磺胺类抗生素药物具有着高效的降解去除效果, 具有广泛的应用前景.     

离子交换树脂预处理/离子色谱法测定镁铝合金中微量氯

镁铝合金试样用稀硫酸溶解后通过装有强酸性阳离子交换树脂的分离柱以除去试样溶液中大量镁及铝离子。通过交换柱的试液以及洗涤交换柱用的高纯水接受于1 L容量瓶中,用高纯水定容。分取25μL试液作离子色谱测定氯,对离子交换分离及离子色谱测定的条件作了试验和优化。离子色谱测定氯离子的标准曲线的相关系数为0.999 1,方法的检出限为1.03μg.L-1。根据精密度试验结果计算得其相对标准偏为4.5%。在6个试样中各加氯标准200.0 mg.kg-1作回收率试验,所得结果在94.1%~106.0%之间。     

吡啶类螯合树脂对Cu(Ⅱ)和Ni(Ⅱ)吸附分离特性的研究

以自合成的氨基吡啶(ANA)树脂为吸附剂,研究其对单组分重金属离子的吸附行为和在双组分体系中对目标重金属离子的分离去除能力。单组分静态吸附实验结果表明,在pH值为5条件下,ANA树脂对Cu(Ⅱ)和Ni(Ⅱ)的吸附容量分别达到1.022mmol/g和0.446mmol/g。静态吸附等温线和动力学过程可采用Langmuir方程和Lagergren二级动力学方程进行拟合。在Cu(Ⅱ)/Ni(Ⅱ)双组分体系下,Cu(Ⅱ)的吸附量较单组分大,高浓度Ni(Ⅱ)条件下,Cu(Ⅱ)在ANA树脂上具有更好的吸附选择性能。前222BV、248BV出水中,Ni(Ⅱ)纯度分别高达100%、99.999%,经简单浓缩处理即可进行回收利用,为树脂在高纯金属制备技术中的应用提供理论指导和技术支持,同时在有色金属资源的深度提纯和高级应用中具有重要的经济和战略意义。     

β-环糊精包裹的方酸类化合物在纯水体系中对CN-的选择性识别

利用β-环糊精包裹方酸类化合物(SQ),很好地改善了SQ在纯水体系中的溶解度.包合物中SQ的两个苯环分别嵌入到两个不同的β-环糊精的空腔内,而中间的四元环裸露在外边.方酸类化合物在近红外区强而窄的吸收以及它们对氰化物特有的敏感性使它们成为理想的氰根离子的传感器.β-环糊精的包裹作用使不溶入水的SQ能够直接在纯水体系中选择性识别氰根离子而不需要任何化学修饰.     

Application of Ion Exchange Techniques to Industrial Process of Metal Ions Removal From Wine

In this article, the application of selective ion exchange resins to the industrial metals removal of wine has been studied as an alternative to the "blue clarification" technique. In this sense, under the perspective of using this technology in the metals removal of sherry wines, a set of experiments at laboratory and pilot plant scale have been carried out. The study shows the behavior of several alkaline ions, metal ions and other parameters (pH, colour, protein index, etc.) during the process. Moreover, using the general theoretical model for continuous multistage processes, this study contemplates also the engineering design and the economic balance of the industrial process based on ion exchange columns. The experimental results demonstrates that ion exchange techniques are more effective and economic than "blue clarification" for metals removal of sherry wines. The proposed practice does not produce alterations in the qualities of the products; it achieves stability enough and also permits an important decrease of the contents of heavy metals.     

微囊化海藻酸离子移变凝胶的制备、结构与性能

通过静电脉冲技术制备了海藻酸-壳聚糖-海藻酸(Alginate-Chitosan-Alginate,ACA)微胶囊,红外光谱分析表明,ACA是一种以聚电解质配合物为囊膜,以海藻酸钠离子吸附剂为囊心物的微胶囊型离子吸附体系.扫描电镜测试表明,ACA吸附重金属离子的过程是微胶囊囊内海藻酸凝胶化的过程,其解吸附过程是海藻酸凝胶转变成海藻酸溶液的过程.与传统离子交换树脂相比,ACA对Pb²⁺的吸附具有较高的去除率、很强的富集能力和较低的极限吸附浓度,并且能够被多次重复使用.ACA的离子交换速率比传统离子交换树脂快得多,离子交换过程中,交换离子和吸附剂海藻酸分子的相互扩散大大提高了离子交换速率.     

低压离子色谱柱及其分离机理

介绍了低压离子色谱柱的种类、分离对象、分离机理及洗脱体系的选取情况     

Ab Initio Calculation of the Structure and Functions of Sulfo Cation Exchangers

An ab initio calculation has been carried out for hydrated lithium, sodium, potassium, and rubidium toluenesulfonates, modeling the structure of sulfo cation exchangers in the form of alkali metal ions. In the optimized structure, water molecules are incorporated between the fixed ion and the counterions. This leads to dissociation of the ionogen groups, which increases the diffusion mobility of the counterions. Analysis of an elementary ion exchange process has revealed that cleavage of hydrogen bonds between the hydration water molecules of the fixed ion and the counterions plays a critical role in the ion exchange mechanism.     

Cobalt(II) and Nickel(II) Transfer through Charged Polysulfonated Cation Exchange Membranes

The transport of Co(II) and Ni(II) ions through charged polysulfonated ion exchange membranes under Donnan dialysis conditions has been studied as a function of pH gradient at 25 degrees C. In the Donnan dialysis process, the membrane is bounded by two electrolyte solutions, the one side (donor phase) initially containing metal salts and the other H(2)SO(4) with no external potential field applied. The transport of metal ions through membranes was correlated with the flux data as well as with estimated diffusion coefficients and was found to depend on the interaction between the fixed groups in the membrane and the metal ions. It was observed that the pH gradient influences the transport of metals and the flux of ions increases with H ion concentration in the receiver phase. Copyright 2000 Academic Press.     

Retention of Some Metal Ions and Their Separation on Silica Gel Modified with Acid Red 88

 Acid Red 88 is strongly extracted by chloroform solutions of Aliquat 336 by an ion exchange mechanism and for its reextraction from the ion pair formed, relatively high concentrations of mineral acids are required. By impregnation of silica with the ion pairs between the cation of Aliquat 336 and the anion of the dye a chelating sorbent for metal ions can be obtained. The sorbent prepared may be successfully used for separation of mixtures of various metal ions by the column extraction chromatography technique, additional purification of sodium and potassium salts from ions of heavy metals and for concentration of trace amounts of ions of various metals from aqueous solutions followed by their quantitative determination. The sorbent can be used repeatedly in the process of sorption and desorption of metal ions (especially those forming less stable complexes with the reagent) after regeneration with solutions of perchloric acid. Received January 28, 1998. Revision March 1, 1999.     

Synthesis and ion exchange behaviour of polyaniline Sn(IV) arsenophosphate: a polymeric inorganic ion exchanger

Incorporation of a polymer material into an inorganic ion exchanger provides a class of hybrid ion exchangers with a good ion exchange capacity, high stability, reproducibility and selectivity for heavy metals. Such a type of ion exchanger ‘polyaniline Sn(IV) arsenophosphate’ has been synthesized by mixing polyaniline into inorganic material. This material is characterized using X-ray, IR, TGA studies in addition to ion exchange capacity, pH-titration, elution and distribution behaviour. On the basis of distribution studies, the material has been found to be highly selective for Pb(II). Kinetic study of exchange for the metal ions has been performed and some physical parameters such as self diffusion coefficient D₀, energy E_a and entropy ΔS* of activation have been determined.     

Ion Exchange in Hydrometallurgical Processing: An Overview and Selected Applications

Ion exchange has traditionally been employed for the purification of water and the removal of metal contaminants from dilute waste streams. More recently, its use in removing trace metallic impurities from hydrometallurgical process streams (with typical background metal concentrations of 50–100 g/L) has increased substantially. It is also used as a primary recovery and concentration unit operation for certain commodities, where both technical and cost advantages become apparent for complex flow sheets. This overview discusses selected modern applications of ion exchange in hydrometallurgical processes for uranium, precious metals, copper, cobalt, nickel and zinc, and identifies some opportunities for the future.     

Atomistic insights into aqueous corrosion of copper

Corrosion is a fundamental problem in electrochemistry and represents a mode of failure of technologically important materials. Understanding the basic mechanism of aqueous corrosion of metals such as Cu in presence of halide ions is hence essential. Using molecular dynamics simulations incorporating reactive force-field (ReaxFF), the interaction of copper substrates and chlorine under aqueous conditions has been investigated. These simulations incorporate effects of proton transfer in the aqueous media and are suitable for modeling the bond formation and bond breakage phenomenon that is associated with complex aqueous corrosion phenomena. Systematic investigation of the corrosion process has been carried out by simulating different chlorine concentration and solution states. The structural and morphological differences associated with metal dissolution in the presence of chloride ions are evaluated using dynamical correlation functions. The simulated atomic trajectories are used to analyze the charged states, molecular structure and ion density distribution which are utilized to understand the atomic scale mechanism of corrosion of copper substrates under aqueous conditions. Increased concentration of chlorine and higher ambient temperature were found to expedite the corrosion of copper. In order to study the effect of solution states on the corrosion resistance of Cu, partial fractions of proton or hydroxide in water were configured, and higher corrosion rate at partial fraction hydroxide environment was observed. When the Cl(-) concentration is low, oxygen or hydroxide ion adsorption onto Cu surface has been confirmed in partial fraction hydroxide environment. Our study provides new atomic scale insights into the early stages of aqueous corrosion of metals such as copper.     

The importance of cerium substituted phosphates as cation exchanger-some unique properties and related application potentials

Seven different samples of an inorganic ion exchanger, cerium phosphate, suitable for column use have been prepared under varying conditions. The property of these exchangers has been characterized by Inductively Coupled Plasma Spectroscopy. These exchangers are stable in water, dilute mineral acids, ethanol, methanol, acetone and ether. However, in concentrated HCl and HNO(3) they decompose. They retain about 50% of their exchange value after drying at 80 degrees C, and can be regenerated twice without any decrease in exchange capacity. The distribution coefficient measurements for alkaline earth metals, tellurium, iodine and molybdenum using these seven ion exchangers were studied. This revealed the relative affinity for each exchanger, where the sorption in general was most effective at pH 6-8. The titration curves of cerium phosphate (disodium) with alkaline earth metals showed that the selectivity sequence Ba(2+)>Sr(2+)>Ca(2+)>Mg(2+) is observed. Furthermore, it could be deduced that the adsorption of alkaline earth metal cations greatly depends on the cation. These studies have also shown that cerium phosphates with divalent ions are strongly preferred to monovalent ones. Therefore, as for the cerium phosphates with large monovalent ions, the lack of exchange for Ba(2+), Mg(2+) or other alkali earth metal ions should be essentially due to steric hindrance and this could include any one of the following: the large crystalline radius of metal ions or large hydrated ionic radius and high energy of hydration for other divalent ions. Three binary separations of Te(IV)-Mo(VI), Te(IV)-I(I) and Mo(VI)-I(I) has been developed and the recovery ranging from 90 to 100% has been achieved on cerium phosphate (disodium) columns.