氯离子选择性电极电位法测定光气含量

光气是医药、染料、农药等有机合成的重要原料,也是剧毒的气体。因此,对光气的分析测定也是十分重要。分析光气的方法颇多,诸如气相色谱法、高压液相色谱法、吸光光度法等。但用离子电极法国内外报道者甚少,曾查阅到日本专利报道过用玻璃电极法测光气,由于文献不全未进行验证。本文根据氯离子的电化学特性采用氯离子电极探讨了光气含量的氯离子选择性电极电位测定法。对光气合成或环境保护监测具有一定的实用和参考价值。     

用电位滴定法测定配合物的组成

本文提出了一种用电位滴定法来测定配合物真正组成的数学模型，只要有两组Ｅ～Ｖ数据即可直接计算出结果，方法简便快速，应用面也较广。     

氯离子选择电极瞬时电位分析法研究

0.1mol/L KNO3空白液与Cl^-切换时，AgCl电极响应的瞬时电位信号峰高度△Ep有非常好的再现性，40多天所测的10次标准曲线电位平衡偏差小于2.0mV，△Ep-p(Cl)^-直线平均斜率为55.4mV，其平均偏差小于1.0mV，电极响应下限和△Ep-p(Cl)^-直线截距都与经AgCl溶度积所计算的值一致，瞬时信号峰电位上升时间小于1.5s，可实现小体积试液的快速准确分析，用离子水合吉布氏自由能△Gh(Cl)^-，的变化解释了瞬时信号不同阶段的电位变化速度，实验中使用自制的活度阶梯自动切换装置，该装置具有容积比为4：1的空白液和试液两个注射泵，用该法已测定了维生素B6的含量。     

巯基化合物分离富集技术的应用进展

根据负载(或鳌合)巯基的物质不同,分别对巯基棉、巯基葡聚糖凝胶、巯基纸、巯基活性炭和巯基树脂等分离富集剂的制备、应用及机理进行了综述。     

巯基化合物自组装单分子层的研究进展

超薄层有机材料的制备与研究￣［１］受到人们的广泛关注，有关研究结果和进展正在不断丰富着人类对表面结构与性质关系的理解和认识。与其它制备单分子层的技术相比，自组装技术是一种较新的制备方法，在８０年代后期，迅速成为有关学科的研究焦点。采用此技术制备的超薄层体系主要有两类：一类是巯基化合物在金、银、铜、铂表面吸附形成的单层￣［２，３］，一类是在硅、玻璃、金属氧化物表面通过硅烷化反应形成的单层￣［４］。其中，硫醇类分子自组装单层（ｓｅｌｆ－ａｓｓｅｍｂｌｅｄｍｏｎｏｌａｙｅｒ，３ＡＭ）是被研究得最为广泛和深入的体系。本文主要综述十年来巯基化合物ＳＡＭ的研究进展。     

巯基化合物在分析中的应用

本文评述了巯基化合物在分析中的应用。叙述了其在一般的元素分析以及接着在各种吸附剂或电极的表面制得巯基吸附剂或巯基修饰电极从而用来富集测定微量元素的进展情况，引用文献达２２０篇。     

聚苯胺薄膜化学修饰电极对巯基化合物促进作用的研究

本文利用聚苯胺薄膜化学修饰电极对巯基化合物的促进作用进行了研究,结果表明,这种促进作用是对巯基乙醇在PAn薄膜表面的氧化还原过程的一种加强,而这种加强作用是通过-SH与PAn中的N以质子形式加成的。     

铜的催化动力学电位法测定

本文报道了利用碘离子选择电极监测Ｈ２Ｏ２－ＫＩ氧化还原反应体系被Ｃｕ（Ⅱ）催化的反应速度，建立了测定Ｃｕ（Ⅱ）的催化动力学方法，其线性范围为１０－８０ｎｇ／ｍＬ，该法用于铝合金标样中铜的测定，结果非常接近标准样品的标准值，相对标准偏差为０．３６％，回收率在９８．３％－１０５．６％之间。     

基于双氢青蒿素-巯基化合物电化学探针对巯基化合物的检测

在20%乙醇+B-R缓冲溶液(pH7.2)介质中,利用双氢青蒿素与谷胱甘肽、6-巯基嘌呤及L-半胱氨酸作用,分别于-1.05,-1.20和-1.10V处获得双氢青蒿素-巯基化合物复合物灵敏的还原峰,该还原峰在一定浓度范围内随着巯基化合物以及双氢青蒿素浓度的增加而增大,因此可将其作为电化学探针应用于上述3种巯基化合物以及双氢青蒿素的检测,为检测巯基化合物提供了一种新方法;探讨了复合物形成的电极反应机理,利用纳米金与巯基的共价作用阻断巯基参与形成复合物,证实了复合物是由双氢青蒿素中的碳自由基与巯基化合物巯基中的硫原子通过SC键结合形成。     

New Validated Potentiometric Determination of Vasodilator Pentoxifylline in its Pharmaceutical Formulations and Biological Fluids

The construction and performance characteristics of pentoxifylline selective electrodes were developed. Two types of electrodes: plastic membrane I and coated wire II were constructed based on the incorporation of pentoxifylline with phosphotungstic acid (PTA). The influence of membrane composition, kind of plasticizer, pH of the test solution, soaking time, and foreign ions on the electrodes was investigated. The electrodes showed a Nernstain response with a mean calibration graph slope of 56.77 ± 0.19 and 55.76 ± 0.71 mV decade^‐1 at 25 °C for electrode I and II respectively, over pentoxifylline concentration range from 1.0 × 10^‐5‐1.0 × 10^‐2 and 9.0 × 10^‐6‐1.0 × 10^‐2 mol L^‐1, with detection limits 4.89 × 10^‐6 and 3.90 × 10^‐6 mol L^‐1 for electrode I and II, respectively. The pH range of the constructed electrodes was 4‐6. Interferences from common cations, alkaloids, sugars, amino acids and drug excipients were reported. The results obtained by the proposed electrodes were also applied successfully to the determination of the drug in its pharmaceutical preparations and biological fluids.     

用二点滴定法测定化合物的组成比

本法只要测定三组E—V数据即可计算出化合物的组成比。     

Determination of total fluoride in HF/HNO3/H2SiF6 etch solutions by new potentiometric titration methods

In the photovoltaic industry the etching of silicon in HF/HNO₃ solutions is a decisive process for cleaning wafer surfaces or to produce certain surface morphologies like polishing or texturization. With regard to cost efficiency, a maximal utilisation of etch baths in combination with highest quality and accuracy is strived. To provide an etch bath control realised by a replenishment with concentrated acids the main constituents of these HF/HNO₃ etch solutions including the reaction product H₂SiF₆ have to be analysed. Two new methods for the determination of the total fluoride content in an acidic etch solution based on the precipitation titration with La(NO₃)₃ are presented within this paper. The first method bases on the proper choice of the reaction conditions, since free fluoride ions have to be liberated from HF and H₂SiF₆ at the same time to be detected by a fluoride ion-selective electrode (F-ISE). Therefore, the sample is adjusted to a pH of 8 for total cleavage of the SiF₆²⁻ anion and titrated in absence of buffers. In a second method, the titration with La(NO₃)₃ is followed by a change of the pH-value using a HF resistant glass-electrode. Both methods provide consistent values, whereas the analysis is fast and accurate, and thus, applicable for industrial process control.     

Potentiometric and Coulometric Determination of Carbimazole

ABSTRACT

A method for the determination of carbimazole involving its reaction with iodine in an alkaline medium is presented. In volumetric titration with potentiometric end-point detection the range of determination is 30–500 μmol (5.6–93 mg). In coulometric titration using biamperometric end-point detection, 0.5–20 μmol (0.09–3.7 mg) of carbimazole was successfully determined. The coulometric titration was applied to the determination of carbimazole in tablets.     

Potentiometric responses of ion-selective electrodes after galvanostatically controlled incorporation of primary ions

A new method of quantitative incorporation of primary cations into ion-selective membrane by means of galvanostatic cathodic polarization/conditioning, before measurement step, was proposed and tested on the example of potassium-selective electrode with ionophore - valinomycin in poly(vinyl chloride) based membrane and with polypyrrole solid contact. Open circuit potential values recorded after polarization can be quantitatively explained by changes of primary cations and ionophore concentration in the surface part of the membrane. The influence of potassium ions concentration in the membrane (in relation to ion exchange sites amount) on the shape of potentiometric calibration plots was also observed. Improved characteristics, with extended linear range, can be obtained for membrane of minor loading with primary cations (around 25%), the responses are relatively stable in course of following calibrations.     

动力学电位法测定硼

本文根据硼酸，苯乙醇酸，孔雀绿形成三元离子缔合型配合物的反应，用孔雀绿离子选择性电极监测反应速率，在最佳实验条件下，用固定时间法，电位变化与硼量在０．２－５．０μｇ／ｍＬ范围呈线性关系，用於测定标准钢样和玻璃标样中的硼，结果与标准值十分接近。     

Ionic Liquids Modify the Performance of Carbon Based Potentiometric Sensors

A new type of potentiometric sensor based on a recently constructed carbon ionic liquid electrode (CILE) is described. Two kinds of ionic liquids, i.e., N‐octylpyridinium hexafluorophosphate (OPFP) and 1‐butyl‐3‐methylimidazoluim hexafluorophosphate (BMFP) were tested as binder for construction of the carbon composite electrode. The characteristics of these electrodes as potentiometric sensors were evaluated and compared with those of the traditional carbon paste electrode (CPE). The results indicate that potentiometric sensors constructed with ionic liquid show an increase in performance in terms of Nernstian slope, selectivity, response time, and response stability compared to CPE.     

电位双点滴定法测定巴比妥类药物

本文提出在Ｎａ２ＣＯ３水溶液中，ＡｇＮＯ３为滴定剂，用电位双点滴定法测定巴比妥类药物的含量。该方法测定巴比妥类药物简便快速。