Fluorescence Properties of Europium and Terbium Triundecylenate-Containing Polymers and Solutions

Europium triundecylenate, Eu(UA)₃, and terbium triundecylenate, Tb(UA)₃, were prepared by the method described in our previous paper. Either Eu(UA)₃ or Tb(UA)₃ was dissolved in methacrylic acid (<20%) and copolymerized as a crosslinker with methyl methacrylate (>80) by bulk polymerization in molds made of two glass plates. The fluorescence spectroscopy of these Eu- or Tb-containing polymers under ultraviolet/visible excitation light was investigated. The fluorescence spectroscopy of solutions of Eu(UA)₃ or Tb(UA)₃ in methacrylic acid was measured and compared with that of the solid-state Eu- or Tb-containing polymers. The fluorescence excitation and emission spectra of the solutions and polymers showed the characteristic features of free Eu³⁺ or Tb³⁺. The lifetime fluorescence of the solutions and polymers with Eu³⁺ are also included.     

铁(Ⅲ)-依诺沙星-SDS三元体系的荧光特性及应用

喹诺酮类药物是一类化学合成抗菌素，在临床上有重要用途。由于其分子结构的特殊性，它们可与许多金属离子发生络合反应，根据其分子吸收或荧光光谱的变化可对药物或金属含量进行测定。依诺沙星（Erloxacin）是临床上广泛应用的第三代喹诺酮类药物，其分子本身具有内源性荧光。本文在实验中发现，在表面活性剂十二烷基硫酸钠（SDS）的存在下，微量铁（Ⅲ）的加入可使依诺沙星的内源性荧光显著猝灭，据此建立了铁（Ⅲ）-依诺沙星-SDS三元体系测定微量铁（Ⅲ）的荧光分析方法。该法灵敏、准确，直接用于水样和食品中微量铁的测定，结果满意。     

Fluorescence Sensitization of Aqueous Terbium and Europium Ions Without Aromatic Donors or Synergistic Agents

Abstract

EDTA and DTPA complexes of terbium and europium are excited at wavelengths below 250 nm. producing the typical lanthanide emission through energy transfer from the complex to the coordinated metal. This allows determination of these rare earth ions in water without solvent extraction, the use of synergistic agents, or aromatic sensitizers. Terbium-EDTA has the most efficient energy transfer, 31%, giving a 165-fold emission enhancement and a limit of detection of 6 × 10^?7 M. Calibration curves are linear over a concentration range spanning three orders of magnitude. The characteristic lanthanide ion emission is obtained in all cases, but the excitation of the complexes is pH dependent, showing intensity increases up to pH 12. Mild interference by alkali and alkaline earth metals was overcome by increasing the ligand concentration, but transition metal interference was more severe. Only minor enhancement was observed at higher ligand/metal ratios.     

The application of oscillating chemical reactions to analytical determinations

Oscillating chemical reactions, which are far from equilibrium, are extremely sensitive to certain species and may provide new analytical methods using the regular oscillations as well as the non-equilibrium stationary state after system bifurcation. This review of their application to analytical chemistry from 2005 to 2012 includes other appropriate references. Both organic and inorganic analytes are included.     

Spectrophotometric study of some Mn(II) ternary complexes and their analytical applications

Abstract  

New ternary complexes of Mn(II) with py, bipy, and terpy as primary ligand (L₁) and 2′,4′,5′,7′-tetraiodofluorescein (I₄FlCOOH) as secondary ligand (L₂) were prepared. The stoichiometry for these complexes was found to be Mn(II):L₁:L₂ = 1:2:1, and the complex formula proposed is [Mn(L₁)₂(I₄FlCOO)]⁺. The effect of substituent groups of L₂ and the nitrogen atoms of L₁ on complex formation with Mn(II) was studied. Moreover, the interference of some cations and anions in the determination of Mn(II) by this method was investigated and the interferences of Cu(II) and Fe(III) with Mn(II) in their corresponding alloys were considered. A simple, rapid, and sensitive spectrophotometric method for determination of Mn(II) in its salts and Mn in its alloys is suggested.     

The application of ternary complexes to spectrofluorometric analysis

The use of ion-association and co-ordination-unsaturated ternary complexes for the spectrofluorometric determination of trace elements is reviewed.     

Fluorescence anisotropy: application in quantitative enzymatic determinations

In this work a method is presented for the enzymatic determination of glucose using fluorescence anisotropy. During the enzymatic reaction a change in the fluorescence anisotropy of the glucose oxidase (GOx) is produced; the reaction time at which this change appears (t_m) depends on the glucose concentration. A theoretical study has been developed which enables: (a) the correlation of this change in anisotropy with changes in the intensity and the lifetime of the enzyme fluorescence; from this a model which could be generalized to other flavo-enzymes is proposed; (b) the linking of t_m with glucose concentration.After optimisation, the proposed method allows the determination of glucose over the range 100-1000 mg l⁻¹. The detection limit is 90 mg l⁻¹and the reproducibility is better than 4% (n = 6, [glucose] = 250 mg l⁻¹). Anisotropy is more selective than conventional fluorescence intensity, and this method has therefore been applied to direct glucose determination in fruit juices without the interference caused by the inner filter effect.     

Potentiometric studies of binary and ternary complexes of amoxycillin

The formation equilibria for the binary complexes of copper(II), nickel(II), cobalt(II) and zinc(II) with amoxycillin (Amx) and for the ternary complexes M(Arm)(Amx), where Arm refers to aromatic amines, namely 2,2′-dipyridyl or 1,10-phenanthroline, were investigated by a potentiometric technique. The protonation constants of amoxycillin and conditional stability constants of the formed complexes were determined at 25° (=0.1M NaNO₃). Probable mode of chelation with amoxycillin is discussed.     

Uncertainty of analytical determinations

Two examples of uncertainty calculation are described for determination of nitrates in solution (APHA method 4500B) and total suspended solids in water (APHA method 2540D).     

pH-metric studies on some ternary complexes of lanthanones

Stepwise mixed ligand complex formation has been cited for the formation of 111,Ln(III)—NTA—catechol ternary complexes potentiometrically [whereLn(III)=La(III), Pr(III) or Nd(III)]. The results of titration curves indicate the formation of 11,Ln(III)—NTA complexes in beginning and the addition of catechol, takes place later on in the higher buffer region. The relative stability of these ternary complexes in terms of metal ion has been reported as La(III)< 相似文献   

Electronic tongues and their analytical application

Electronic tongues for liquid analysis, based on the organizational principles of biological sensory systems, developed rapidly during the last decade. A brief historical overview of the research and development in the field of electronic tongue systems is presented. Current achievements of scientific groups working in this field are outlined and critically reviewed. The performance of electronic tongues in quantitative analysis and in classification of multicomponent media is considered. The exciting possibility of establishing a correlation between the output from an electronic tongue and human sensory assessment of food flavour, thereby enabling quantification of taste and flavour, is described. Application areas of electronic tongue systems including foodstuffs, clinical, industrial, and environmental analysis are discussed in depth. Prospective research and development in the field of electronic tongues is discussed.     

萘啶酮酸体系荧光法测定铕,铽,镝

本文研究了萘啶酮酸体系荧 光法同时测定铕、铽、镝的最佳条件。     

铽-钆-钛铁试剂体系荧光光度法测定铽

研究了铽－钆－钛铁试剂协同发光体系的荧光光谱特性,确定了各种试验条件对体系荧光强度的影响,由于钆对铽－钛铁试剂荧光体系有协同发光效应,在铽－钛铁试剂荧光体系中引入适量的钆可使体系的荧光强度提高３０倍,体系的荧光强度与铽的浓度在２．０×１０＾－９－－６．０×１０＾－６ｍｏｌ／Ｌ范围内呈线性关系,检测限达５．０×１０＾－１１ｍｏｌ／Ｌ。采用标准加入法测定混合稀土样品中痕量的铽,测定满意结果。     

乳清酸/异乳清酸体系荧光法测定铕、铽、镝

对比研究了乳清酸和异乳清酸对某些稀土离子特征荧光的增敏情况，发现异乳清酸比乳清酸更有效地使Eu^3 、Tb^3 、Dy^3 的特征荧光增敏。建立了乳清酸，异乳清酸体系荧光法测定Eu^3 、Tb^3 、Dy^3 的新方法，在乳清酸体系中Eu^3 、Tb^3 、Dy^3 的检出限分别是0．73、0．065mg，L，在异乳清酸体系中Eu^3 、Tb^3 、Dy^3 的检出限分别是0．88、0．0023、0．59mg/L。该方法用于混合稀土氧化物中Eu^3 、Tb^3 、Dy^3 含量的测定，结果满意。     

稀土铕、铽配合物在温度发光传感领域的研究进展

稀土发光配合物材料基于其独特的4f-4f电子跃迁表现出优异的发光性能,特别是铕和铽配合物材料,发光波长在可见光区范围内,发射谱带狭窄且尖锐(半峰宽通常小于10 nm),非常适合应用于显示设备和传感装置.同时,具备温度依赖发光性能的铕和铽配合物能够实现高灵敏度、高效的温度传感过程,使其有望用于流体动力学、航空航天、环境工...     

氧化铽团簇的表面修饰及对其荧光特性影响的研究

采用脉冲激光轰击浸于流动相中的氧化铽固体靶，考察了流动相及其流速、脉冲激光输出功率、修饰剂、添加修饰剂顺序等对所获得的氧化铽有机溶胶荧光性能的影响。UV-Vis和荧光光谱的测试表明：以含有修饰剂的无水乙醇作为流动相，可得到良好荧光性能的氧化铽乙醇溶胶，而环己酮与醋酸乙酯均不适合作为该体系的流动相;最佳流速为0.15 mL·s^-1；脉冲激光输出功率大有利于其荧光性能；最佳修饰剂为乙酰丙酮(acac)和2，2′-联吡啶(2，2′-bipy)，且应原位修饰。     

Electroanalytical characteristics of enoxacin and their analytical application

In a 0.050 M HCl solution containing 0.12 M KCl, enoxacin yields a sensitive polarographic wave at -1.05 V, which can be used to determine trace amounts of the drug, the linear range being from 1.6 x 10(-8) to 1.6 x 10(-5) M with a detection limit of 6.25 x 10(-9) M. The electrochemical characteristics of the drug were studied by normal polarography, cyclic voltammetry and potentiostatic coulometry. A single-sweep polarographic procedure for the determination of enoxacin has been worked out and applied to urine and serum samples.