铜—腺嘌呤络合物吸附波的研究

了在０．０８ｍｏｌ／ＬＮａＡｃ～０．０２ｍｏｌ／ＬＨＡｃ缓冲溶液铜与腺嘌呤（Ａｄｅ）络合物的极谱行为，结果表明，扫描电压为－０．２Ｖ～－０．７Ｖ时铜－腺嘌呤络合物在单扫示波极谱上有一络合物吸附波，其一阶导数峰电位主－０．４Ｖ（ｖｓ．ＳＣＥ），腺嘌呤浓度在１．０×１０＾－６～１．０×１０＾－５ｍｏｌ／Ｌ范围内与一阶导数波高呈良好的线性关系，检出限为１．０×１０＾－７ｍｏｌ／Ｌ，实验证明，该峰具有吸附     

铜（II）—腺嘌呤的配位吸附波

本文对铜（Ⅱ）－腺嘌呤配位吸附波的极谱行为进行了研究。结果表明，当腺嘌呤浓度大于铜的浓度时，极谱波呈现为两电子还原配位吸附不可逆波。测定了配合物的组成及条件生成常数，对电极反应机制也进行了探讨。     

聚腺嘌呤核苷酸在金电极上的吸附氧化

采用微电极循环伏安法和吸附转移溶出伏安法研究了单链多聚腺嘌呤核苷酸Poly(A)在金电极上的伏安行为。重点了考察了Poly(A)的吸附和氧化过程。发现Poly(A)分子在金电极表面能够形成多种状态的特性吸附。影响吸附态和吸附强度的主要因素是吸附电势, 吸附时间和溶液浓度。在负电位区, 随着吸附时间(t~s)的变化, Poly(A)分子在金电极表面发生不同状态的以腺嘌呤碱基为吸附位点的强吸附, 这种以腺嘌呤碱基吸附的Poly(A)分子能够在零伏附近给出很强的氧化电流峰和对应的还原峰。     

铜(Ⅱ)-腺嘌呤的配位吸附波

本文对铜（Ⅱ）－腺嘌呤配位吸附波的极谱行为进行了研究。结果表明，当腺嘌呤浓度大于铜的浓度时，极谱波呈现为两电子还原配位吸附不可逆波。测定了配合物的组成及条件生成常数，对电极反应机制也进行了探讨。     

二氧化碳在铜氧化膜电极上的光电化学还原

本文研究了CO_2在铜阳极氧化膜电极上的光电化学还原行为,在还原电量小于0.1C时,CH_4 的产率较高;还原电量大于2.0C时,主要还原产物为CH_3OH,还对CH_4的产率随外加电位、还原电量和铜阳极氧化膜制备条件的变化关系进行了研究,并对其还原机理作了初步探讨。     

核黄素在玻碳电极上的电化学行为

用电位扫描、旋转环盘电极和微分电容等方法研究了核黄素在玻碳电极上的电化学行为。在ｐＨ〈６的介质中，观察到一个典型的氧化还原波，它是可逆的二电子反应，其还原产物ＲＦＨ２在电极上的吸附为弱吸附，溶出性能良好，在６〈ｐＨ〈１０的介质中，出现两个分离但仍有部分重叠的氧化还原波，相应于两步单电子反应，还原所生成的ＲＦＨ和ＲＦＨ２发生吸附，很难溶出。在ｐＨ〉１０的介质中，仍然出现两个分离但有部分重叠的氧化还原     

在汞电极上酮糖还原的电化学行为

用极谱法及恒电位电解法研究了酮糖中的单糖、果糖、塔格糖、二糖、拉克杜糖的电还原行为，由酮糖的电还原行为从理论上导出了相应的极谱电流－电压方程，该方程被实验所证实，成功地解释了实验现象。恒电位电解后电解的分析结果表明，电解选择性为１００％，电解产物为由酮糖还原成相应的多元醇。     

meso-四(4-磺基苯基)卟啉在汞电极预吸附与铜、锌等离子形成络合物的伏安法研究

一般水溶性金属卟啉络合物要在溶液加热或有某种催化剂存在下才能形成。本文报道将乙酸缓冲液中的meso-四(4-磺基苯基)卟啉(TPPS_4)预先吸附于汞滴电极,取出电极,洗净,插入仅含Cu~(2+)的相同底液中,在单扫伏安图上就可得到Cu-TPPS_4络合物的还原峰。利用峰高可测定微量铜以及研究络合物的电化学行为。同样,在氨性底液中,吸附了卟啉的汞滴电极插入含Cd~(2+)、Zn~(2+)、Co~(2+)、Mn~(2+)等离子的溶液中,也可快速地得到相应的络合物还原峰。这是一个简便且重现性很好的形成和研究金属卟啉络合物的新方法。     

吸附条件对活性碳纤维SACF氧化还原吸附Ag^＋的影响

本文研究了吸附条件对活性碳纤维ＳＡＣＦ氧化还原吸附Ａｇ＾＋的影响。结果表明：Ａｇ＾＋初始浓度的提高，反应温度的升高均可提高ＳＡＣＦ对Ａｇ＾＋的吸附量；Ａｇ＾＋的吸附量还强烈地依赖于溶液的ＰＨ值，用ＮａＡＣ、ＨＡＣ＋ＮａＡＣ或ＮＨ３．Ｈ２Ｏ调高Ａｇ＾＋溶液的ＰＨ，可有效地增加ＳＡＣＦ对Ａｇ＾＋的吸附量；用ＮＨ３．Ｈ２Ｏ调节会再现一个最佳的ＰＨ值；通过增加ＳＡＣＦ用量，Ａｇ＾＋的吸附率可达９９％以上。     

活性碳纤维ZCSACF的制备及其氧化还原吸附性能

用ＺｎＣｌ２溶液浸泡剑麻纤维，然后高温处理而制备出海拔恶性循环碳纤维ＺＣＳＡＣＦ，借助于ＡＡＳ＜ＷＡＸＤ，ＳＥＭ和ＩＲ探讨了ＸＣＳＡＣＦ对贵金属离子的氧化还原吸附行为。实验结果表明与水汽活化的ＳＡＣＦ相比，ＺＣＳＡＣＦ可在较低的温度下，第八是度高，并对贵金属离子具有较高的吸附量，可以认为，ＺＣＳＡＣＦ比ＳＡＣＦ具有更多更强的还原性基团。ＺＣＳＡＣＦ的氧化还原吸附能力受制备工艺。如处理温度和Ｚｎｃｌ     

Adsorptive Stripping Voltammetric Determination of Albendazole at a Hanging Mercury Drop Electrode

ABSTRACT

Albendazole is determined by differential-pulse adsorptive cathodic stripping voltammetry at a hanging mercury drop electrode using the reduction peak of its copper(II) complex at ?0.28V at an accumulation potential 0.0V vs. Ag/AgCl electrode. The optimum conditions of pH, accumulation potential and accumulation time were studied. The calibration graph for the determination of albendazole was linear in the range 3.0X10^?8 - 9X10^?7M with a relative standard deviation of 2.8%. The detection limit was 1.0X10^?8M after 180s accumulation at 0.0V. The effect of common excipients and metal ions on the peak height of albendazole was studied. The presence of Cu²⁺ ions forms a stable complex with albendazole which is strongly adsorbed at the mercury electrode surface. The method was applied to the determination of the drug in commercially available dosage forms.     

Determination of Amitraz Pesticide by Adsorptive Stripping Voltammetry on the Hanging Mercury Drop Electrode

 A sensitive method for the determination of amitraz pesticide at nanomolar level by adsorptive stripping voltammetry at a hanging mercury drop electrode is described. The cyclic voltammograms demonstrate the adsorption of this compound on the mercury electrode. A systematic study of the various experimental parameters, that affect the stripping response, was carried out by differential pulse voltammetry. Using an accumulation potential of −0.50 V, and 30 s accumulation time, the limit of detection was found to be 2.3 × 10⁻⁹ mol L⁻¹ and the relative standard deviations (n = 5) was 2.2% at concentration level of 5.0 × 10⁻⁸ mol L⁻¹ of amitraz. The influence of diverse ions and some other pesticides was investigated. Finally, the method was applied to the determination of amitraz in spiked soil and water. The relative standard deviation is 4.5% for 5 determinations of amitraz in water and 3.2% for 5 determinations in soil. Received December 6, 2000. Revision March 1, 2001.     

米托蒽醌的吸附行为及其吸附伏安测定法研究

本文研究了米托蒽醌在悬汞电极上的吸附行为，在此基础上建立了米托蒽醌的吸附伏安测定方法。在ｐＨ为２．２的Ｂ．Ｒ缓冲体系中，米托蒽醌浓度在１．１×１０＾－６ｍｏｌ／Ｌ～１．１×１０＾－９ｍｏｌ／Ｌ范围内，浓度与电流呈线性，检出限可达５．５×１０＾－１０ｍｏｌ／Ｌ。若在盐酸－柠檬酸钠（ｐＨ为１．２５）缓冲体系中，检出限可低至１．１×１０＾－１１２ｍｏｌ／Ｌ。方法可用于尿样或血样中米托蒽醌的测定。     

Adenine Determination in the Presence of Copper in Diluted Alkaline Electrolyte by Adsorptive Stripping Voltammetry at the Mercury Film Electrode

Highly sensitive, simple and inexpensive techniques of adenine determination are particularly interesting in relation to the present development of ATP and DNA sensors. A nanomolar concentration of adenine can be determined in the presence of copper. For an accumulation time of 30 minutes, the detection limit found was 0.22 ppb (1.63×10^?9 M). The method is based on controlled adsorptive accumulation of adenine‐copper at thin‐film mercury electrode followed by linear scan voltammetric measurement of the surface species. By applying a condition time of 60 s at ?0.9 V, the same thin‐film can be used over several measurements. Optimum experimental conditions were found to be the use of a 5.0×10^?3 M NaOH solution, an accumulation potential over the ?0.20 to ?0.40 V range, and a scan rate of 100 mV s^?1. The response of adenine‐copper is linear over the concentration range 20–100 ppb. The more convenient ways to measuring adenine in the presence of metals and other nitrogenated bases were also investigated. The adenosine triphosphate (ATP) or deoxyribonucleic acid (DNA) are first treated with acid (e.g., 0.1 M perchloric acid), and the acid‐released adenine (without separation from others products of the degradation) is directly determined by adsorptive stripping voltammetry.     

Electroanalytical Studies of Biologically Active Azosalicylic Acid at a Hanging Mercury Drop Electrode

The electrochemical behavior of disodium 3,3′‐azobis‐(6‐hydroxy‐)benzoate (olsalazine sodium), 2‐hydroxy‐5‐[(4‐sulfophenyl)azo]benzoic acid and 2‐hydroxy‐5‐azo‐benzoic acid was studied as a simple model of the metabolic reduction of azosalicylic acids using cyclic and square‐wave voltammetry. The stability of the hydrazo intermediate generated in the electroreduction process is strongly dependent on pH and the effect of different substituents in the aromatic ring adjacent to the azo bridge. The electrode mechanism of azosalicylic acids at hanging mercury drop electrode exhibits characteristic properties of a surface redox reaction. The kinetic parameters of azo/hydrazo reduction, such as the standard redox reaction rate constant and the electron transfer coefficient were estimated applying the methods of a split SW peak and a quasireversible maximum. A sensitive analytical method for the determination of trace level of biologically active azosalicylic acids by square‐wave voltammetry based on adsorptive stripping technique is described.     

Adsorptive Stripping Voltammetric Measurements of Trace Molybdenum at the Bismuth Film Electrode

Bismuth‐film electrodes on glassy‐carbon substrates have been successfully applied for adsorptive‐stripping voltammetric measurements of trace molybdenum in the presence of chloranilic acid (CAA). The procedure is based on the preconcentration of the molybdenum‐chloranilic acid complex at a preplated bismuth film electrode held at ?0.55 V (vs. Ag/AgCl), followed by a negatively‐sweeping square‐wave voltammetric scan. Factors influencing the adsorptive stripping performance, including different ligands, solution pH, CAA concentration, preconcentration time and potential, have been optimized. The response compares favorably with that observed at mercury film electrodes, and is linear over the 5–50 μg/L Mo concentration range (one min preconcentration). A detection limit of 0.2 μg/L molybdenum is obtained following a 10 min accumulation. High stability is indicated from the reproducible response of a 100 μg/L molybdenum solution (n= 60; RSD=2.6%). Applicability to seawater samples is demonstrated.     

Voltammetric and Differential Pulse Stripping Study of Adenine on a Sol‐gel Derived Carbon Composite Electrode

This communication reports on the electrochemical investigation of adenine on a sol‐gel carbon composite electrode (CCE). Cyclic voltammetric (CV) technique is used to characterize the redox behavior of adenine at CCE. The peak current and peak potentials are dependent on the pH of the buffer solution. From the scan rate and peak current study, there is evidence of adsorption of adenine on the CCE. The parameters affecting the differential pulse stripping adsorption peak were systematically optimized. Under optimum conditions of E_acc=?0.10 and t_acc=60 s, a linear calibration plot was obtained, 2×10^?7–1×10^?6 M. This CCE is useful for the simultaneous analysis of adenine and guanine from denatured DNA.     

牛红细胞铜锌超氧化物歧化酶（BESOD）在汞电极表面吸附行为的研究

牛红细胞铜锌超氧化物歧化酶（ＢＥＳＯＤ）在汞电极表面吸附行为的研究钱雯，孟庆国，罗勤慧，沈孟长（南京大学配位化学研究所，配位化学国家重点实验室南京，２１００９３）关键词铜锌超氧化物歧化酶，吸附，循环伏安，双阶跃计时电量超氧化物歧化酶是超氧离子（·Ｏ）...     

杯芳烃修饰玻碳电极吸附溶出伏安法测定微量铅

研究了以杯芳烃衍生物修饰玻碳电极,以其吸附溶出伏安法测定微量铅。对富集时间、铅的浓度、支持电解质、样品溶液pH值及部分离子干扰等进行了实验。实验发现以氢氧化钠溶液处理修饰电极可提高测定灵敏度,经过优化处理后,线性范围和检出限分别为5.0×10-7～1.0×10-5mol/L和1.0×10-8mol/L。应用本法对合成水样进行了测定,结果满意。本文还对吸附溶出机理进行了讨论。