卟啉在高效液相色谱-光度法测定痕量金属离子方面的应用

评述了当前卟啉类化合笺在高效液相色谱－光度法测定痕量金属离子方面的应用研究，展望了此研究领域的发展前景，参考文献６５篇。     

用 meso-四(对三甲铵基苯)卟啉三阶导数分光光度法测定铅的研究

卟啉类试剂是一种高灵敏显色剂,其金属络合物的摩尔吸光系数大都在10~5以上,有的甚至达10~6数量级。应用该类试剂进行痕量金属离子测定已有不少报道、用meso-四(对三甲铵基苯)卟啉光度法测定铅的工作也有发表。这一方法虽有很高的灵敏度,但     

在表面活性剂存在下用T(4-TAP)P作显色剂导数光度法同时测定铜和锌

前言卟啉类试剂在光度法中作为高灵敏显色对金属离子的测定有很多报导,一般都采用常规光度法进行单个元素的测定,其ε值均在1×10~5—4×10~5之间。用卟啉作显色剂的导数光度法测定微量金属离子,文献曾报导过,但尚未见到在表面活性剂存在下,用卟啉作显示剂的导数光度进行二种金属离子用时测定的报道。导数光度法是测量吸光度对波长的导数输出信息d~n/dλ~n,对提高光度法的灵敏度、准确度、选择性,或实现多元素连测等方面都较常规光度法优越。本文试验表明:T(4-TAP)P     

钯的光度分析新进展

随着石油化学工业的飞速发展,作为铂族元素的钯,在生产和科研中的应用日渐增多,如在生产中,通过催化剂中加入适量钯来提高产品转化率,降低副产物的生成量。因此,为了更好地指导生产,就需要及时准确地测定催化剂及中间产物中的钯含量。钯的分析方法种类繁多,各种新的分析方法亦在不断推出,其中光度分析法因其灵敏度高,操作简便,分析速度快,而倍受欢迎。 本文就钯的光度分析1989～1996年发展状况,从各类显色剂、显色反应条件、灵敏度、干扰情况和实际应用等方面加以归纳和概述。1卟啉衍生物试剂光度法 近年来,应用于钯光度分析的卟啉类衍生物日益增多,在文献[1～4]中均有不同的报道。这类试剂之所以受到分析工作者的重视,一是因为卟啉衍生物尤其是非水溶性卟啉衍生物具有易合成、易提纯、结构类型多等特点;二是因为它们是目前光度法测定痕量钯的最灵敏显色剂。李友芬等研究的α,β,γ,δ-四（4-二甲氨基苯基）卟啉[T（4-DMAPP）]在十     

DMTAQ光度法测定微量镍的研究及应用

早在1888年Traumarn就提出了4-(2-噻唑偶氮)-间苯二酚(TAR)和1-(2-噻唑偶氮)-2-萘酚(TAN)等噻唑偶氮化合物,但并未研究它与金属离子的生色性和在分析上的应用.噻唑偶氮类试剂是继吡啶偶氮类试剂之后发展起来的另一类重要的有前途的显色剂.此类试剂中的基本分析功能团是:由于其中电负性大的氮、氧等原子共同存在并同时参与金属螯合物的形成,从而增强了邻羟基偶氮酚与金属离子的生色作用,提高了显色反应的灵敏度.此类试剂在分析化学中的应用已见诸报道.自Savvin S B于1970年首次合成2-(2-4,     

卟啉类试剂在分析化学中的应用进展

根据卟啉类试剂的特性,从其在分析化学中的显色性、荧光性、超分子特性、电化学活性等方面,简要综述了近几年来卟啉类试剂在分析化学中的应用进展情况.     

纯铜中痕量铅的光度测定

国家标准技术规范中规定,一号铜中铅的含量应低于0.003%.常用的分析方法有二苯硫腙光度法、原子吸收光谱法和极谱法等.就光度分析范畴而言,二苯硫腙法的应用已有较长的历史,但由于其选择性不够,需用剧毒的氰化物作掩蔽剂.现经改进,可不用氰化物作掩蔽剂,但因操作较繁,易受试剂中杂质及器皿、环境等方面的治污而导致测定的失败.因此对此项测定的改进一直是分析工作者的研究目标,希望建立一种操作较简便而且重现性较好的方法.在显色体系的研究方面已有不少报道,例如碘化物-碱性染料的高灵敏体系,催化动力学测定法,荧光光度法以及包括卟啉类在内的新显色剂的反应体系等.其中变色酸偶氮类试剂用于 Ph(Ⅱ)的光度测定的进展值得注意.曾提出用偶氮胂Ⅲ测定铜合金中铅.近年来一些不对称结构的变色酸双偶氮类试剂应用于铅的光度测定也频见报道.但应用于纯铜中痕量铅的测定尚需解决灵敏度的提     

高灵敏度显色剂在分光光度法测定铅中的应用

综述了近年来国内各类高灵敏度的显色剂,包括卟啉类、变色酸双偶氮试剂、甲基百里香酚蓝等显色剂的显色原理及其在分光光度法测定铅离子中的应用(综述文献46篇)。     

香蕉皮对重金属离子铅的吸附性能研究

建立了香蕉皮快速、高效对重金属离子铅吸附性能的方法。采用分光光度法测定重金属离子铅的浓度,分别研究了7种不同形态的吸附剂对废水中重金属离子铅的吸附性能。在优化的实验条件下,重金属离子铅浓度与吸光度的线性相关系数R=0.999 83,且方法相对标准偏差(RSD)低于3%。结果表明,香蕉皮对废水中的重金属离子铅有良好的吸附效果,吸附率达到91.3%。利用香蕉皮去除废水中的重金属离子,可以变废为宝,且方法吸附率高、准确可靠、精密度高,可用于吸附废水中重金属离子铅。     

光度法在铬(Ⅵ)测定中的研究进展

论述了2006～2009年光度法在铬（Ⅵ）测定中的研究进展．现今测定铬（Ⅵ）的光度法主要包括吸光光度法、催化动力学光度法、荧光光度法和原子吸收光谱法．近年来,人们开始关注流动注射光度法和共振光散射光谱法．这2种光度法在铬（Ⅵ）的测定分析中克服了传统方法的试剂稳定性差、选择性较差等缺点．具有灵敏度高、选择性好、试剂消耗量少和分析速度快等优点．随着分析方法的改进创新和新技术的应用,铬（Ⅵ）光度分析方法将逐步向高灵敏度、高选择性和自动化方向发展．     

Clean analytical methodology for the determination of lead with Arsenazo III by cyclic flow-injection analysis

A clean analytical methodology, where the sample determined and the reagent used are both toxic, has been proposed. A cation exchange mini-column was incorporated after the flow-through cell for on-line regeneration of the main reagent and the accumulation of heavy metal ions. The method involves the spectrophotometric determination of lead with Arsenazo III, the accumulation of lead onto the cationic exchanger, and subsequent regeneration of the chromogenic reagent, which makes the system reversible and the reagents reusable. The developed method provides a satisfactory way to cut down on the toxic reagent consumption and the produced volume of waste, an important step towards the zero emissions research initiative concept. The excellent repeatability and reproducibility, and the simplicity of this method are well suited for continuous measurements. The method was successively applied to the assay of lead in high-octane gasoline.     

A double-line sequential injection system for the spectrophotometric determination of copper, iron, manganese, and zinc in waters

A double-line sequential injection system was developed for the spectrophotometric determination of several metal ions in waters. The proposed double-line configuration was used to enable adding sample and chromogenic reagents as merging zones. The methodology was applied to the spectrophotometric determination of copper, iron, manganese, and zinc in samples of diverse origins at the range of 0.15-5.00, 0.10-10.0, 0.48-4.00, and 0.11-5.00 mg/L, respectively. Different chromogenic reagents and detection wavelengths were used. The chromogenic reagents for iron and manganese were 1,10-phenanthroline and formaldoxime, respectively. Copper and zinc were both determined using the analytical reagent zincon. Analytical characteristics of the methodology, such as manifold parameters, buffer pH, and reagent concentrations were optimized, and interference of some of the metal ions commonly present in water sample was assessed. Results of the analysis were in agreement with those obtained by atomic absorption spectrometry. Repeatability, expressed as the relative standard deviation for 10 consecutive injections of water samples, was lower than 6%. The determination rate was approximately 36/h.     

A New Metal Sensitive Flourescence Reagent

Abstract

A new crown ether based fluorophoric reagent which is sensitive to divalent metal ions (e.g., Ca, Mg, Cd) is presented, The reagent displays enhanced flourescence emission when forming a complex with metal cations. The solvent system used has a profound effect on the performance of the reagent, and non-aqueous media was found to produce the most favorable conditions with respect to both sensitivity and complexign ability. Although the ligand possesses intrinsic acid/base sensitive flurescence and spectroscopic properties, the metal sensitivity is not attributed to protonation-deprotonation chemistries as is the case for many of the currently available chromogenic and fluorogenic crown reagents. Furthermore, the sensitivity of the new reagent is markedly influenced by what anion is associated with the metal of interest and the water content of the solvent matrix.     

Thin-Layer Chromatographic Separation of Copper and Mercury Chelates

Abstract

Thin-layer chromatographic separation of metal ions has become immensely popular in analytical chemistry in view of its speed, selectivity and applicability at tracer level. Quinoline-2-aldehyde thiosemicarbazone^1,2 was found to form yellow coloured chelates with metal ions such as copper, nickel, zinc, mercury, iron and lead at pH 7.5 and extract into chloroform. This, however reduces the sensitivity of the reagent as a chromogenic agent but the chromatographic run of the chelates on a thin layer of silica gel coated on glass plate increases the specificity and selectivity of the reagent. In this article we propose a method for separation of copper and mercury chelates from binary mixtures containing chelates of zinc, lead, iron and nickel. The method is applicable for analysis of synthetic mixtures and standard samples.     

Optoelectronic and Self‐assembly Properties of Porphyrin Derivatives with Click Chemistry Modification

A series of functionalized porphyrin molecules containing electron‐rich alkynes, synthesized by means of the Sonogashira coupling reaction were further modified by reacting the ethynyl groups with click reagent through a formal [2+2] click reaction. The photophysical and electrochemical properties of the porphyrin derivatives were studied by UV/Vis spectroscopy and cyclic voltammetry. We show that the optoelectronic properties are affected by the click reagent groups and central metal ions. The functionalized porphyrin molecules show strong charge‐transfer (CT) bands in the visible region (near‐IR region) and potent redox activities. Through a phase‐exchange self‐assembly method, the highly organized morphologies were observed by scanning electron microscopy (SEM). The functionalized porphyrin molecules represent an interesting set of candidates for optoelectronic device components. The effect of the metal ions or click reagent groups on the self‐assembly properties were also studied by the UV/Vis spectroscopic titration experiments.     

Preliminary evaluation of biacetyl bis(2-pyridyl)hydrazone as an analytical reagent

With the purpose of introducing biacetyl bis(2-pyridyl)hydrazone as an analytical reagent, the pyridylhydrazone literature has been reviewed. BBPH acts as a general chromogenic reagent. The fundamental solution chemistry of the complexes formed by BBPH with the metal ions has been studied. BBPH appears to be a promising reagent for the colorimetric estimation of cobalt and palladium. It may be advantageously compared with benzil bis(2-pyridyl) hydrazone which has the same basic chelate structure.     

共沉淀分离富集偏最小二乘法在茶叶重金属测定中的应用

以铜试剂为共沉淀剂,在pH值为10.0的条件下,共沉淀分离富集茶叶中痕量金属离子Ni^(2+)、Pb^(2+)、Cd^(2+)和Cu^(2+),并分析了铜试剂与金属离子形成配合物的最佳沉淀条件.用4-(2-吡啶偶氮)间苯二酚(PAR)作为这4种重金属离子的显色剂进行分光光度测定,采用偏最小二乘-紫外可见光度法同时测定了四组分金属离子的模拟混合试样,并在茶叶中进行上述金属离子含量的测定.方法操作简便、结果可靠,对茶叶中重金属测定有一定实用价值.     

A new Hg(2+)-selective chromoionophore based on calix[4]arenediazacrown ether

A new azophenol type chromogenic ionophore based on the p-tert-butylcalix[4]arenediazacrown ether was prepared: the ionophore exhibited a pronouncedly selective chromogenic behaviour toward Hg2+ ions among the surveyed guests of alkali, alkaline earth, transition and heavy metal ions in liquid-liquid extraction experiments.     

Selectivity behaviour of a bonded phosphonate--carboxylate polymeric ion exchanger for metal cations with varying eluent compositions

The chromatographic behaviour of a commercially available ion-exchange stationary phase (the Dionex IonPac CS12A column) is described for a wide range of transition and heavy metal ions with nitric acid eluents containing chloride and nitrate potassium salts. The separation selectivity was found to arise from simultaneous ion-exchange interactions and chelation with the attached carboxylic and phosphonic acid groups. These interactions were investigated by altering the ionic strength and pH of the eluent and also the column temperature. Strong affinity of the stationary phase towards heavy metal ions, in particular bismuth and the uranyl ion was observed at low pH under chelating ion-exchange conditions, with high efficiency separations of other ions including cadmium and lead being possible with short analysis times (approximately 5-15 min). Examples are given of separations obtained using 4-(2-pyridylazo)resorcinol or Arsenazo III as the post-column chromogenic reagents, demonstrating the potential versatility and utility of this stationary phase for heavy metal ion analysis.     

Differential kinetic analysis and flow injection analysis: Part 3. The (2.2.2) Cryptates of Magnesium,Calcium and Strontium

Simultaneous determinations of strontium and magnesium or calcium ions in solution can be done by differential kinetic analysis in continuous flow systems. Two different approaches are described; both are based on the differences between the dissociation rates of the cryptand (2.2.2) complexes of the metal ions, in the presence of potassium ions as scavenger and phthalein complexone as the chromogenic reagent for the released metal ions. Analyses were carried out at 40 h^-1, injected sample volumes were 25–150 μl.