金在微电极上的电沉积研究

本工作利用微循环伏安法和阶跃电位法研究在ＡｕＣｌ３的酸性溶液中金在玻碳和铂微电极上的电沉积行为。结果表明，金在微电极上成核所需的过电位较高，但成核几率也高，在所研究的微电极尺寸范围内，金可形成大量的临界单核，且核的生长速率很快。铂微电极上金电沉积的Ｉ－ｔ曲线符合连续成核的模式。     

以H2O2微电极阵列为基础电极的葡萄糖传感器

以Ｈ＿２Ｏ＿２微电极阵列为基础电极的葡萄糖传感器朱建中，刘晓辉，吴佳俐，陆德仁，林心如，张国雄（中国科学院上海冶金研究所，上海２０００５０）葡萄糖传感器在生物和医学上有极其重要的应用价值。国外采用Ｈ＿２Ｏ＿２，微电极（ＭＥ）作为基础电极，然后将葡萄糖...     

微电极研究 ⅩⅢ.聚苯胺修饰微盘电极的研究

用恒电流法在盐酸介质中以最佳聚合条件将聚苯胺修饰在Ｐｔ微盘电极上。制得的聚苯胺修饰微盘电极对ｐＨ有能斯特响应，稳定性好，用于样品测定，结果满意。     

组合式微电极的性质与应用

本文介绍各种形式的组合微电极及其最新发展;总结制作这类电极的材料与方法;讨论它们的基本特性,并对其应用和发展趋势作了评述。     

组织胺敏感离子选择性微电极及其应用

合成了四对三氟甲基苯硼酸钠和三氟甲基苯硼－组织胺离子缔合牧，以该离子缔合物为对组织胺敏感的电活性物，进行了组织胺离子选择性的研究，同时制备了对 敏感的双通道离子选择性 电极，并对电极进行了考核。     

氢离子选择性液膜超微电极的研制

本报道新的以三－十二烷基胺（ＴＤＤＡ）为载体和以对氯苯硼四－十二铵（ＥＴＨ２１９１）为载体的ｐＨ微电极膜，与原有的ＴＤＤＡ膜相比较，新的ＴＤＤＡ膜和ＥＴＨ２１９１膜制备更加容易，膜内阻从原有的２×１０＾１１Ω（１μｍ）下降到３．５×１０＾１０Ω（１μｍ），其中ＥＴＨ２１９１膜的动力学响应ｐＨ范围为１２～４．５，与原有的ＴＤＤＡ膜（ｐＨ范围为１２～５．５）比较，拓宽了１个ｐＨ，而且ＥＴＨ２１９１膜     

C60微电极伏安法研究

自从1990年用电弧法成功地制备出宏观量的C60和C70以来，富勒烯的电化学研究有了迅速的发展．理论研究指出，在一个C60簇化合物中，有六个吡喃环烯单元，可分别得到一个电子使五元环芳香化，从而形成C（n＝1～6）阴离子．Haufler首先报导了C60可逆的两步单电子还原，之后一些作者陆续得到了三步、四步和五步单电子电还原过程．直到达1992年，在使用混合溶剂并控制低温-10℃至5℃和-88℃至60℃条件下，才得到了C60的六步电还原伏安图．富勒烯的微电极伏安法的研究极少见报导．杨汉西等用铂微电极得到了C60三步电还原的稳态伏安图．本文在…     

毛细管电泳的微机化安培法检测

毛细管电泳的微机化安培法检测胡深，李培标，程介克（武汉大学化学系，武汉，４３００７２）关键词毛细管电泳；微电极；安培法检测；微型计算机安培法电化学检测器用于毛细管电泳有独特的优点，如线性范围宽，选择性好，可以进行生物微环境电活性物质的分离检测［１，２...     

对插型阵列微带电极的制作及其电化学特性研究

用微电子光刻方法制作了对插型阵微带电极（ＩＤＡ），并通过ＳＥＭ对ＩＤＡ电极进行了表征，将微Ａｇ／ＡｇＣｌ参比电极和微铂丝对电极固定在ＩＤＡ电极附近，构成了微电解池，考察了该电极的循环伏安及计时电流特性，并用微带电极的扩散理论和Ｃｏｔｔｒｅｌｌ 公式对ＩＤＡ电极的准稳太电流进行了处理，指出了它们之间产生偏差的原因，研究了ＩＤＡ电极的“发生－收集”效应，测定了该电极的屏蔽因子、反馈因子和收集效率。     

硫辛酸修饰碳纤维微电极在抗坏血酸共存下选择性测定神经递质多巴胺

本研究了硫辛酸修饰电化学活化碳纤维电极。此电极在测定脑神经递质多巴胺（ＤＡ）时，具有较高的灵敏度和较好的选择性，它能够有效地消除抗坏血酸（ＡＡ）的干扰。该电极测定多巴胺的线性范围为１×１０＾－８－１×１０＾－５ｍｏｌ／Ｌ；检出下限为５×１０＾－９ｍｏｌ／Ｌ。     

Differential potentiometric stripping analysis

Differential potentiometric stripping analysis, a sensitive instrumental modification of potentiometric stripping analysis, is described. For trace elements like cadmium and lead, which exhibit transport-controlled potentiometric stripping, signal enhancement is possible by employing a scheme involving multiple stripping and re-reduction of the preconcentrated analytes. For such elements the detection limit is below 5 × 10^-10 M with 60-s plating. The accuracy of the technique is tested on a biological reference material. Like potentiometric stripping analysis, the technique presented is not sensitive to reversible redox couples in solution.     

Simultaneous determination of cadmium and lead in urine by means of computerized potentiometric stripping analysis

In computerized potentiometric stripping analysis for cadmium and lead in urine the samples are acidified with hydrochloric acid to a total concentration equal to 0.5 M. The sample is pre-electrolyzed at —1.25 V vs. SCE for 2 min without prior sample heating or deoxygenation, the working electrode being a mercury pre-coated glassy-carbon electrode. The lead and cadmium concentrations are evaluated by means of standard addition. Detection limits are 1 nM for both elements. Results obtained by potentiometric stripping analysis and by solvent extraction/atomic absorption are compared for samples from unexposed persons and from one patient under penicillamine treatment. The relative merits of the potentiometric stripping, anodic stripping and atomic absorption techniques are discussed.     

超微盘电极上电位溶出分析法理论

本文提出了超微盘电极上电位溶出分析法理论,内容包括:过渡时间(τ)方程式、电位(E)-时间(t)曲线方程式及微分电位溶出分析法dt/dE-E曲线方程式,并对该曲线的性质进行了论述。     

间断多次扫描电位溶出分析方法的研究

间断多次扫描电位溶出分析是在多次扫描电位溶出分析和间断扫描伏安法的基础上提出的一种新的电位溶出分析技术,它不仅具有多次扫描电位溶出分析灵敏度高的优点,又克服了多次扫描电位溶出分析对多元素分析时元素之间相互干扰的缺点。文章讨论了间断多次扫描电位溶出分析的实验条件,同时用这种方法分析了人尿中镉、铅的含量。间断多次扫描电位溶出分析在电积10分钟时,最低可检测到0.005ng/mL的镉和0.01ng/mL的铅。镉、铅浓度为4ng/mL时,相对标准偏差分别为2.9%和3.2%,证明间断多次扫描电位溶出分析可以同脉冲阳极溶出伏安法媲美。     

Potentiometric stripping analysis at a stationary electrode

The feasibility of controlling the transport mechanism of the oxidizing species at the working electrode during the stripping step of potentiometric stripping analysis is demonstrated. When linear diffusion of the oxidizing species is the rate-determining mechanism at the working electrode/solution interface and when the physical properties of the medium are considered to lower the diffusion coefficient of the oxidizing species, the relative sensitivity of the technique is enhanced by a factor of 50 for all the common ions studied by potentiometric stripping analysis. Examples and comparison with the normal procedure are given for Cu, Cd, Zn, Pb, Bi, Tl and Ga. The “stationary electrode” procedure is compatible with the normal instrumentation without great modification; it is self-optimizing with respect to time and resolution and preserves all the inherent advantages of potentiometric stripping analysis compared to other electrochemical techniques of trace analysis. The enhancement of the relative sensitivity by this modification permits measurements in the 0.01–0.1 ppb range for metal ions; the total time required is 2–4 min for a single determination and the relative standard deviations are about 3%.     

Multiple-scanning potentiometric stripping analysis

A computerized data acquisition technique— multichannel potentiometric monitoring—is used in conjunction with potentiometric stripping analysis. Multiple-scanning stripping potentiograms can be recorded so that the analytical signals are enhanced. A minicomputer with an internal store of4K 16-bit words suffices for experimental control and data treatment. The technique is suitable for stripping analysis with preconcentration times of 60–90 s at a mercury film electrode with linear response ranges of 1–100 μg l^-1 for cadmium(II) and lead(II). For preconcentration times of 30 min, the limit of detection is about 5 ng l^-1. Preliminary tests on continuous flow analysis are reported.     

A micro-computer system for potentiometric stripping analysis

In potentiometric stripping analysis, trace metals are first amalgamated into a mercury film electrode and then oxidized back into solution by an oxidant. The potential vs. time curve is recorded. Microcomputer-controlled equipment for automation of the potentiometric stripping analysis is described. The higher resolution of time compared to manual equipment increases the sensitivity of the method. A resident, 3-kB BASIC interpreter with routines for handling the hardware makes the programming simple and the instrumentation flexible for changes in the analytical scheme. Printer and keyboard are incorporated in the equipment which makes the whole analyser compact.     

Flow potentiometric stripping analysis for mercury(II) in urine,sediment and acid digest of biological material

In flow potentiometric stripping analysis for mercury in urine, the samples are acidified with concentrated nitric acid and heated to boiling for 10 min. After cooling, the samples are buffered by the addition of concentrated ammonia and then pre-electrolysed at a gold working electrode for 90 s at -0.25 V vs. SCE at a flow rate of 1.75 ml min^-1. The stripping solution is 1 M sodium bromide solution acidified with 0.1 M hydrochloric acid and containing chromium(VI). The detection limit at one sigma level is 0.05 μM. Orchard leaves, sediment and fish muscles are digested in nitric acid at 140°C for 30 min prior to buffering with ammonia and potentiometric stripping analysis for 200 s at -0.20 V vs. SCE at a flow rate of 1.75 ml min^-1.     

Potentiometric stripping analysis

The analytical possibilities of potentiometric stripping analysis are outlined. The technique comprises reduction of metal ions at a stationary mercury drop or thin-film electrode. The amalgamated metals are then re-oxidized with mercury(II) ions, and the time—potential behaviour of the mercury electrode is recorded. The technique is compared with d.c. and differential pulse anodic stripping analysis.     

Effect of electroactive substances forming water-soluble reduced species on the potentiometric stripping determination of mercury soluble metals

When localized regions with high concentrations of water-soluble reduced species are formed during the electrolysis period of potentiometric stripping analysis, the stripping signals arising from oxidation of amalgamated metallic analytes are overlapped by interfering signals. Dissolved reduced species may give rise to plateaux on the potential vs. time curve. If the re-oxidation of such reduced species is governed by transport, plateaux are developed at the equilibrium potential of the soluble redox system, while an anodic translation of plateaux is observed when the re-oxidation is kinetically controlled. These effects complicate the potentiometric stripping determination of, for example, cadmium and lead in complex samples such as decomposed, dissolved fly ash. This paper deals with the mechanisms leading to interference. It is shown that increased transport rates induced by vigorous stirring eliminate the interference problems.