血清蛋白-荧光素复合物单扫极谱波与应用

在0．08mol／L的HAc中，荧光素与牛血清白蛋白(BSA)或人血清白蛋白(HSA)相互作用形成复合物。复合物使荧光素在-0．58V(vs．SCE)处的还原峰电流增大，峰电流的增大值与加入的BSA或HSA的浓度在一定的范围内呈线性关系。BSA在2—24μg／mL范围内呈线性关系，检出限为1μg／mL；HSA在2—22μg／mL范围里呈线性关系，检出限为0．8μg／mL。应用该法测定了人血清蛋白样品，结果令人满意。     

Micro-Determination of Protein Containing SH– and –S–S– Groups Based on the Polarographic wave of an Electroactive Derivative

This paper presents a new simple and sensitive method for the micro-determination of protein containing SH– and –S–S– groups based on the single sweep polarographic wave of an electroactive derivative. In 0.04molL^–1 Na₃PO₄ and 0.2% ascorbic acid solution, protein is heated in a boiling water bath for 15min, the reaction product giving a sensitive reduction wave at –0.70V (vs. SCE). The wave height is linearly proportional to the concentration of protein. The calibration curves of bovine serum albumin (BSA), human serum albumin (HSA), ovalbumin (OVA) and lysozyme (Lyso) are constructed under the optimal conditions. For BSA and HSA, the linear ranges and detection limits are 0.05–24mgL^–1 and 0.02mgL^–1, respectively. The method has been applied to the determination of protein in human serum samples with satisfactory results. The mechanism of the polarographic wave was also studied, and the results show that S^2– ion is released from the protein molecule during the derivatization reaction, the wave being attributed to the reduction of HgS.     

Langevin dynamic simulation of hysteresis in a field-swept Landau potential

Numerical simulations are done of Langevin dynamics for a uniform-orderparameter, field-swept Landau model,= –|a/2|m ²+|b/4|m ⁴–mh(t) , to study hysteresis effects. The field is swept at a constant rateh(t)=h(0)+ht. The stochastic jump values of the field {h_J from an initially prepared metastable minimumm(0) are recorded, on passage to a global minimum m(). The results are: (a) The mean jump¯h _J(h) increases (hysteresis loop widens) with h, confirming a previous theoretical criterion based on rate competition between field-sweep and inverse mean first-passage time (FPT); (b) The broad jump distribution(h _J,h) is related to intrinsically large FPT fluctuations ( ²–²)/ ² O(1), and can be quantitatively understood. Possible experimental tests of the ideas are indicated.     

二苯并18－冠－6辅助钡离子在1，2－二氯乙烷／水微界面转移的伏安研究

应用液／液界面微电极对二苯并１８－冠－６（ＤＢ１８－Ｃ－６）辅助推动Ｂａ~（２＋）在１，２－二氯乙烷／水（ＤＣＥ／Ｗ）界面转移的电化学过程进行了详细探讨，证明该过程遵循ＴＩＣ机理，是受扩散控制的可逆过程。通过转移电流和反应物浓度之间的线性关系，测定了Ｂａ~（２＋）以及用其它方法难以测定的ＤＢ１８－Ｃ－６。     

Underpotential deposition studies of copper on glassy carbon

Studies on the deposition and dissolution of copper from 0·5 M sulphuric acid solutions onto glassy carbon (GC) using potential sweep techniques indicated that an additional peak occurs at higher positive potentials than the bulk stripping peak. This peak is identified as due to the stripping of underpotential deposited (UPD) copper. Results of investigations on the effect of sweep rate, deposition potential and time of deposition on the peak characteristics of UPD and bulk deposited copper are also reported.     

线性变位极谱法研究 ⅩⅥ.铀(Ⅵ)-5-Br-PADAP-磺基水杨酸的配位吸附波

本文提出了铀(Ⅵ)-5-Br-PADAP-磺基水杨酸三元配合物的极谱配位吸附波。在pH为7.5-8.2的醋酸、三乙醇胺、乙醇底液中,该波的峰电位在-0.6855V(vs.SCE)。在1.00×10^-7-1.00×10^-5mol·dm^-3范围内,铀(Ⅵ)浓度与峰电流呈线性关系。对极谱波的电流、电位性质进行了研究,测定了配合物的组成、表观稳定常数和离解及生成速率常数。     

安力农的极谱测定及其电化学行为

在ｐＨ５．６，０．１５ｍｏｌ／Ｌ磷酸盐缓冲溶液（ＰＢＳ）中，得到了安力农的灵敏极谱吸附波，波的二阶导波高在２×１０＾－８～８×１０＾－６ｍｏｌ／Ｌ范围内与安力农的浓度成直线关系，检测下限为１×１０＾－８ｍｏｌ／Ｌ，测定出电极过程的电子传递系数ａ＝０．４３，表面电极反尖速率常数ｋｓ＝３．３ｓ＾－１，安力农在汞电极上的吸附遵从Ｌａｎｇｍｕｉｒ等温式，测得其吸附系数β＝８．１×１０＾５。     

Trace Detection of Mercury(II) Using Gold Ultra‐Microelectrode Arrays

The electroanalytical detection of trace mercury(II) at gold ultra‐microelectrode arrays is reported. The arrays consist of 256 gold microelectrodes of 5 μm in diameter in cubic arrangements which are separated from their nearest neighbor by 100 μm. The array was utilized in nitric acid using linear sweep voltammetry where a linear response from mercury additions over the range 10 μg L^?1?200 μg L^?1 (10^?8?10^?6 M) was observed with a sensitivity and detection limit of 0.11 nC/μg L^?1 and 3.2 μg L^?1 (16 nM) respectively from using a deposition time of 30 s at ?0.2 V (vs. SCE). This methodology was explored in 0.1 and 1 M chloride media over the mercury range 10 μg L^?1?200 μg L^?1 (5×10^?8?10^?6 M) where similar sensitivities of 0.087 nC/μg L^?1 and 0.078 nC/μg L^?1 were observed with an identical detection limit. The protocol is demonstrated to be useful for the determination of mercury for analysis of environmental water samples.     

Square wave adsorptive stripping voltammetric determination of famotidine in urine

Electrochemical studies of famotidine were carried out using voltammetric techniques: cyclic voltammetry, linear sweep and square wave adsorptive stripping voltammetry. The dependence of the current on pH, buffer concentration, nature of the buffer, and scan rate was investigated. The best results for the determination of famotidine were obtained in MOPS buffer solution at pH 6.7. This electroanalytical procedure enabled to determine famotidine in the concentration range 1 × 10⁻⁹–4 × 10⁻⁸ mol L⁻¹ by linear sweep adsorptive stripping voltammetry (LS AdSV) and 5 × 10⁻¹⁰–6 × 10⁻⁸ mol L⁻¹ by square wave adsorptive stripping voltammetry (SW AdSV). Repeatability, precision and accuracy of the developed methods were checked. The detection and quantification limits were found to be 1.8 × 10⁻¹⁰ and 6.2 × 10⁻¹⁰ mol L⁻¹ for LS AdSV and 4.9 × 10⁻¹¹ and 1.6 × 10⁻¹⁰ mol L⁻¹ for SW AdSV, respectively. The method was applied for the determination of famotidine in urine.     

单扫描示波极谱法测定扑热息痛

扑热息痛与NaNO2在中性介质中发生反应，其亚硝化衍生物具有良好的电活性。在pH9．37的Britton-Robinson缓冲溶液中，于-0．56V(vs．SCE)产生灵敏的极谱还原峰，峰电流与扑热息痛质量浓度在0．007-0．4mg/L范围有良好的线性关系，检测下限为5μg/L。此法已用于测定小儿速效感冒灵。