铊(Ⅰ)-碘化钾-向红菲啰啉络合吸附波的研究

在Ｎａ２Ｂ４Ｏ７－ＮａＯＨ 介质（ｐＨ １０．８）中,可获得灵敏的铊（Ⅰ）－碘化钾－向红菲口罗啉极谱络合吸附还原波,其二阶导数波灵敏度高、波形好,峰电位在－ ０．５８ Ｖ 处（ｖｓ．ＳＣＥ）。波高与铊（Ⅰ）浓度在２．０×１０－ ８～９．０×１０－ ７ ｍ ｏｌ·Ｌ－ １范围内呈线性关系, 检出限１．０×１０－ １０ ｍ ｏｌ·Ｌ－ １。本法用于测定工厂废水中的痕量铊,结果满意。本文还对极谱波的性质和机理进行了研究。     

硼掺杂多晶金刚石薄膜电极的电化学特性

用循环伏安法和恒电位法研究了硼掺杂多晶金刚石薄膜电极（ＤＦＥ）的若干电化学特性。电极面积４×４ｍｍ＾２。在０．１ｍｏｌ／Ｌ ＫＣｌ，ＮａＮＯ３，ＮａＯＨ和ＫＨ２ＰＯ４＋Ｎａ２ＨＰＯ４（ｐＨ＝６．８６）电解质溶液中电势窗口均为－５００￣＋８００ｍＶ；而在０．１ｍｏｌ／Ｌ ＨＣｌ和Ｈ２ＳＯ４溶液中电势窗口为－２００￣＋１１００ｍＶ．Ｋ３Ｆｅ（ＣＮ）６的氧化峰电位为＋５００ｍＶ，与Ｐｔ电极测量相同；校正     

示波极谱测定天然水,食品和生物样品中痕量锡

在Ｈ２ＳＯ４－ＨＣｌＯ４－ＮａＢｒ－（ＮＨ４）２ＶＯ３的体系中，Ｓｎ（Ⅳ）在－０．６０Ｖ左右产生一个非常灵敏的极谱催化谱，Ｓｎ（Ⅳ）浓度在０．８－１６０ｎｇ．ｍＬ＾－１之间与峰电流成线性关系，检测限为０．２６ｎｇ．ｍＬ＾－１。该法应用于天然水、食品和生物样品中痕量锡的测定，结果令人满意。     

3,3‘—四亚甲基—双—（1—苯基—5—吡啶酮—4—羟酸酯）极谱行为研究

ＴＰＰＣ在０．０８ｍｏｌ／ＬＣＨ３ＣＯＯＮａ和０．４ｍｏｌ／ＬＣＨ３ＣＯＯＨ（ＮａＡｃ－ＨＡｃ下同）底液条件下，在电位－１．５７Ｖ附近产生一尖锐的导数波，峰高在３．７×１０＾－６－５．６×１０＾－５ｍｏｌ／Ｌ范围内呈线性关系，同时，讨论了极谱波的性质及电极反应机理。     

三取代钨硅杂多配合物的导电性和磁性

合成了α－ＮａｍＨｎ［ＳｉＷ９Ｍ３（Ｈ２Ｏ）３Ｏ３７］·１６Ｈ２Ｏ（Ｍ＝Ｃｏ（Ⅱ），Ｎｉ（Ⅱ），Ｖ（Ⅴ）杂多配合物），通过ＩＣＰ，ＩＲ，ＵＶ，ＴＧ－ＤＴＡ，ＸＰＳ，ＥＰＲ，极谱等手段进行了表征．配合物在室温下的电导率σ值达１×１０－３Ｓ·ｃｍ－１，３４３Ｋ时可达１×１０－２Ｓ·ｃｍ－１，是有实用化前景的新型固体电解质．变温磁化率结果表明α－Ｎａ１０［ＳｉＷ９Ｃｏ３（Ｈ２Ｏ）３Ｏ３７］·１６Ｈ２Ｏ和α－Ｎａ１０［ＳｉＷ９Ｎｉ３（Ｈ２Ｏ）３Ｏ３７］·１６Ｈ２Ｏ具有反铁磁性．     

钛(Ⅳ)-5-Br-PADAP-NaClO_3体系极谱吸附催化波的研究

２－（５－溴－２－吡啶偶氮）－５－二乙氨基苯酚（５－Ｂｒ－ＰＡＤＡＰ）在极谱和伏安分析中的应用已有一些报道。陈林林等曾经研究过Ｔｉ（Ⅳ）－５－Ｂｒ－ＰＡＤＡＰ络合物在稀Ｈ２ＳＯ４－Ｈ２Ｃ２Ｏ４溶液中的极谱行为,但灵敏度不高（１．０×１０－７ｍｏｌ／Ｌ）。我们发现,在ｐＨ４．１左右的ＨＡｃ－ＮａＡｃ底液中,Ｔｉ（Ⅳ）－５－Ｂｒ－ＰＡＤＡＰ－ＮａＣｌＯ３体系产生一灵敏的极谱吸附催化波,二次导数峰电位在－０．８６Ｖ（ｖｓ．ＳＣＥ）左右,波形良好,波高稳定,检测限可达４×１０－１０ｍｏｌ／Ｌ。１　实验部…     

铅(镉)-二-(邻-甲苯基)硫卡巴腙配合物吸附极谱波法连续测定铅和镉的研究

研究了二－（邻－甲苯基）硫卡巴腙（简写为Ｈ２ＤＭＢＤｚ）与Ｐｂ（Ⅱ）和Ｃｄ（Ⅱ）配合物体系的二阶导数吸附极谱波。在ｐＨ６．０的ＨＡｃ－ＮａＡｃ介质中,Ｐｂ（Ⅱ）－（Ｈ２ＤＭＢＤｚ）和Ｃｄ（Ⅱ）－（Ｈ２ＤＭＢＤｚ）２配合物分别于－０．５２Ｖ（υｓ．ＳＣＥ）和－０．６５Ｖ（υｓ．ＳＣＥ）电位处产生一良好的可逆吸附极谱波。峰电流Ｉ″ｐ１和Ｉ″ｐ２分别与Ｐｂ（Ⅱ）的浓度ｃ１和Ｃｄ（Ⅱ）的浓度ｃ２在０．０１     

芦荟大黄素的电化学研究

用单扫示波极谱法研究了芦荟大黄素的电化学行为。在５％Ｎａ２ＣＯ３＋５％ＮａＯＨ（９＋１）底液中，芦荟大黄素于－０．８４Ｖ（Ｐ１）和－０．９７Ｖ（Ｐ２）处产生两个示波极谱峰，利用Ｐ１可测定芦荟大黄素，线性范围为 ０．１１－２４ｍｇ／Ｌ和３．０－２８．６ｍｇ／Ｌ，检测限为０．０６ｍｇ／Ｌ。将该法应用于中药大黄中的芦荟大黄素的测定，结果满意。另外，讨论了芦荟大黄素清除由邻苯三酚自氧化产生的超氧自由基（Ｏ２）的作用。     

铁（Ⅱ）—亚硝基R盐—双氧水体系极谱波研究及应用

在ｐＨ５．５ＨＡｃ－ＮａＡｃ缓冲溶液中，以硫酸肼还原Ｆｅ（Ⅲ），Ｆｅ＾２＋与亚硝基Ｒ盐生成络合物，在Ｈ２Ｏ２存在下可于－０．３５Ｖ（ｖｓ．ＳＣＥ）处产生一个灵敏的极谱波，二阶导数波高与铁浓度在０．５～２００μｇ／Ｌ范围内呈线性关系，检出限０．３μｇ／Ｌ。研究了极谱波性质和机理。该波为一带吸附性质的平行催化波，络合物中配位体亚硝基Ｒ盐在电极上的还原，还原的中间产物被Ｈ２Ｏ２氧化原来的状态，本法灵敏，     

CO(υ)高振动激发态向C2H2的振动传能研究

用时间分辨富里叶红外发射谱研究了高振动激发态ＣＯ向Ｃ２Ｈ２的传能，得到了ＣＯ（ｖ＝１－３）各振动态布居及其随时间的变化。利用微分法解出弛豫微分方程组，获得ＣＯ（ｖ＝１－３）向Ｃ２Ｈ２的传能速率常数分别为：２．０±０．１，６．０±０．２和９．４±０．８（１０＾－１３ｃｍ＾３·ｍｏｌｅｃｕｌｅ＾－１·ｓ＾－１）。传能速率随着振动量子数的增加而迅速增加。ＣＯ的振动能应向Ｃ２Ｈ２的对称伸缩模ｖ２近共振Ｖ－     

Determination of traces of molybdenum and tungsten by extraction and polarography of their salicoylhydroxamates

Molybdenum and tungsten salicoylhydroxamates have been extracted into methyl isobutyl ketone or a mixture of chloroform and isobutyl alcohol from 1.5M hydrochloric acid and subjected to DC and derivative pulse polarography (DPP) after addition of methanolic lithium chloride solution, phosphoric acid and water in defined proportions. Molybdenum gives two DC waves with E(1 2 ) at -125 and -525 mV and a sharp DPP peak at -75 mV, whereas tungsten shows a single DC wave at -840 mV and a DPP peak at -850 mV. The two metals can be determined down to the sub-ppm level.     

Determination of iron in water samples by adsorptive stripping voltammetry with a bismuth film electrode in the presence of 1-(2-piridylazo)-2-naphthol

An adsorptive stripping voltammetry method for the determination of iron has been developed. The procedure is based on the adsorptive collection of a complex of iron with 1-(2-piridylazo)-2-naphthol (PAN) on a bismuth-coated glassy carbon electrode (BiFE). Factors affecting the stripping performance, such as pH, PAN concentration (C(PAN)), potential, accumulation time (E(ads), t(ads)), and interference by other ions were also studied. The optimum conditions were obtained in a 0.1 mol L(-1) acetate buffer at pH 4.0, C(PAN) 5.0 micromol L(-1), t(ads) 60 s, E(ads) -400 mV, pulse height 4.0 mV, pulse amplitude 25 mV, and frequency 15 Hz. The detection limit was found to be 0.1 microg L(-1) when a t(ads) of 60 s was used, and the linear range was from 0.4 to 60.0 microg L(-1). The proposed procedure was validated by determining of Fe(III) in CRM-MFD, QCS-19 and CRM-SW certified reference materials and applied in seawater samples with satisfactory results.     

Rapid-scan pulse voltammetry

In pulse voltammetry slow scan-rates (1-5 mV/sec) are generally used, so long scan-times are needed to cover reasonable potential ranges. Data are presented to show that fast pulse voltammetry with stationary electrodes and the dropping mercury electrode can provide useful analytical data which fit the theory of conventional pulse voltammetry. The possibility of reducing the capacitive currents and increasing the apparent faradaic current in cyclic pulse voltammetry is also shown.     

Determination of L- and D-fucose using amperometric electrodes based on diamond paste

Monocrystalline diamond (natural diamond, synthetic-1 and synthetic-2) based electrochemical electrodes were designed for the analysis of L- and D-fucose. Response characteristics of the electrochemical electrodes were determined using cyclic voltammetry and differential pulse voltammetry (DPV). L-fucose was determined using DPV with electrodes based on natural diamond, synthetic-1 and synthetic-2, respectively, at 240 mV using NaCl as the electrolyte (pH 3.0); at 160 mV using KNO(3) (pH 10.0) and at 80 mV using KCl as the electrolyte (pH 10.0) while D-fucose was analyzed at 120 mV using KCl as the electrolyte (pH 1.0); at 140 mV using KNO(3) as the electrolyte (pH 1.0) and at 160 mV using NaNO(3) as the electrolyte (pH 3.0). The linear concentration ranges for L-fucose were between 10(-13) and 10(-9) mol L(-1) (natural diamond), 10(-11) and 10(-8) mol L(-1) (synthetic-1) and 10(-6) and 10(-3) mol L(-1) (synthetic-2) with detection limits of 10(-14), 10(-12) and 10(-8) mol L(-1) magnitude order, respectively. For D-fucose, the linear concentration ranges were 10(-6) to 10(-3) mol L(-1) (natural diamond), 10(-5) to 10(-3) mol L(-1) (synthetic-1) and 10(-9) to 10(-3) mol L(-1) (synthetic-2) with detection limits of 10(-7), 10(-7) and 10(-10) mol L(-1) magnitude order, respectively. The sensors were used for the assay of L-fucose in serum and urine samples.     

Adsorptive stripping voltammetric assay of phenazopyridine hydrochloride in biological fluids and pharmaceutical preparations

A sensitive method for the measurement of phenazopyridine hydrochloride (PAP) by differential pulse polarography (DPP) based on adsorptive stripping technique, using a hanging mercury drop electrode (HMDE) is described. The voltammetric peak is obtained at -0.760 V, which corresponds to the reduction of the azo group in Britton-Robinson buffer. The redox behaviour is reversible. Optimum conditions were found to be: accumulation potential -50 mV (vs. Ag/AgCl), accumulation time 60 s, scan rate 5 mV s(-1), pulse amplitude -100 mV and supporting electrolyte Britton-Robinson buffer (0.04 M, pH=11). The relative standard deviation (at 20 ng ml(-1) level) was +/-0.6% for six measurements. The calculated detection limit was 0.0299 ng ml(-1) with a 60-s accumulation time. The applicability of such a method was evaluated through the assay of PAP in human plasma and urine samples after a simple extraction procedure and in pharmaceutical preparation. The mean recovery was 97+/-2 (100 ng ml(-1) plasma).     

Electrochemical Behavior from Pig Spleen Ferritin and Bacterial Ferritin of Azotobacter vinelandii

Being electrochemical studies, a rate of the core potential shifting to negative as a form of -205mV+(-115mV/pH) from horse spleen ferritin (HSF) has been measured by microcoulometry in the presence of mediator such as methyl viologen^[1]. It was well indicated that the mediator played an important role in transferring the electrons between the ferritin and the electrode. However, using cyclic voltammetry of pulse polarography, HSF appeared appreciable currentless at the mercury electrode at scan rate 5 mV.s^-1, moreover, and its mineral core isolated from protein shell showed the reductive current^[2]. Evidently, these results was known that the ferritin shell be no a redox protein due to it no exhibited the current at the electrode at low potential.     

维生素B1的电化学聚合及催化作用

用循环伏安法在石墨电极上制备了VB1聚合膜修饰电极,VB1聚合膜在pH5的PBS中有一对氧化还原峰,峰电位Epd=350mV,Epc=325mV,峰电流与扫描速率的平方根成正比,表明电子在膜中的传递为扩散控制,且聚合膜与VB1单体有不同的电化学性质。实验表明VB1聚合膜对多巴胺、肾上腺素等神经递质有显著的电催化作用。     

Studies on the Electrochemistry of Dopamine at a Pyrocatechol Sulfonephthalein Modified Glassy Carbon electrode

IntroductionThere has been a considerable interest in developing the methods to measure the secretionneurotransmitters. Electrochemical teChniques have proven to be significantly advantageous tothe biosciencesLlj. The application of ultramicroelectrodes to neuroscien.ce, which has been pioneered by Adams[2], to monitor the concentration of neurotransmitters in the central nervesystem has had a special impact. Several neurotransmitters, e. g., dopamine(DA) are electroactlve and therefore can …     

Simultaneous voltammetric determination of molybdenum and copper by adsorption cathodic differential pulse stripping method using a principal component artificial neural network

An adsorption differential pulse stripping method for the simultaneous determination of molybdenum and copper based on the formation of their complexes with cupferron (benzene, N-hydroxy-N-nitroso) is proposed. The optimum experimental conditions were obtained 0.010 mM cupferron, pH 3.0, accumulation potential of -0.15 V versus Ag/AgCl, accumulation time of 60 s, scan rate of 10 mV s(-1) and pulse height of 50 mV. Molybdenum and copper peak currents were observed at -0.16 and +0.02 V, respectively. A principal component artificial neural network (PC-ANN) was utilized for the analysis of the voltammogram data. A three layer back-propagation network was used with sigmoidal transfer function for the hidden and the output layers. The linear dynamic ranges were 5.0-60.0 and 0.1-20.0 ng ml(-1) for Cu(II) and Mo(VI), respectively. The detection limit was 0.06 ng ml(-1) for Mo(VI) and 0.20 ng ml(-1) for Cu(II). The capability of the method for the analysis of real samples was evaluated by the determination of molybdenum and copper in river water, tap water, and alloy.