靛蓝胭脂红的光谱电化学研究——Ⅱ.靛蓝胭脂红复相电子转移动力学

报道了靛蓝胭脂红在SnO_2透光电极上的复相电子转移动力学参数。由光谱电化学和电化学两种实验方法测定。前一方法为单电位阶跃计时吸收法((SPS/CA)。后一方法为循环伏安法。两种方法的数据处理中均应用了计算机拟合,较之文献中常规的工作曲线法更为简便、正确。两种方法测定的结果十分一致。进一步的研究表明,动力学参数值与靛蓝胭脂红的浓度和溶液pH有关,为靛蓝胭脂红在水溶液中的状态提供了重要信息。     

靛蓝胭脂红薄层光谱电化学研究(Ⅰ)

采用SnO_2石英玻璃组装的光透薄层电解池,结合紫外可见光谱现场监测技术,研究了靛蓝胭脂红水溶液的电化学还原与氧化过程.测定了不同pH下的式电极电位(E~0)和电子转移数(n).实验结果表明,靛蓝胭脂红在SnO_2电极上的还原为准可逆的两电子转移过程,而它的氧化则为不可逆电极过程.由电解现场检测的光谱,初步探讨了电解还原与氧化的反应机理。     

靛蓝胭脂红波薄层光谱电化学研究(I)

采用SnO_2石英玻璃组装的光透薄层电解池, 结合紫外可见光谱现场监测技术, 研究了靛蓝胭脂红水溶液的电化学还原与氧化过程. 测定了不同pH下的式电极电位(E~0)和电子转移数(n). 实验结果表明, 靛蓝胭脂红在SnO_2电极上的还原为准可逆的两电子转移过程, 而它的氧化则为不可逆电极过程. 由电解现场检测的光谱, 初步探讨了电解还原与氧化的反应机理。     

靛蓝胭脂红催化褪色光度法测定钴

研究了在弱碱性介质中 ,Co( )对 H2 O2 氧化靛蓝胭脂红的褪色反应催化作用 ,建立了催化动力学光度法测定痕量 Co( )的新方法。方法线性范围为 0～ 1 .0μg/2 5m L ,检出限为 9.92× 1 0 - 7g/L ,反应的表观活化能为 8.66k J/mol,用于水样中 Co( )的分析 ,结果满意     

催化氧化靛蓝胭脂红褪色反应动力学测定痕量铝(Ⅲ)的研究

在H2SOr介质中,痕量铝（Ⅲ）能灵敏地催化KBrO3氧化靛蓝胭脂红使其褪色,据此,建立了测定痕量铝（Ⅲ）的催化动力学新方法。研究了该催化褪色反应的最佳动力学条件并求得有关参数。方法的检出限为1．13ng／mL,线性范围为0．004～0．2μg／mL,将其用于水样（湖水、池塘水、自来水）中痕量铝（Ⅲ）的测定,获得了满意的结果。     

氧化靛蓝胭脂红褪色光度法测定痕量钛(Ⅳ)

基于稀H2SO4介质中,痕量钛（Ⅳ）对溴酸钾氧化靛蓝胭脂红的褪色反应有明显的催化作用,建立了测定痕量钛的动力学光度分析法.方法检出限为0.31μg/L,线性范围为0～8.0μg/L.本法结合溶剂萃取分离技术,用于人发、茶叶及岩石样品中痕量钛（Ⅳ）的测定,结果满意.     

靛蓝胭脂红-溴酸钾催化光度法测定锇

1　引　　言催化光度法测定锇 的试剂有亚甲蓝、DBC 偶氮胂、胭脂红酸等 ,诸方法稳定性欠佳 ,操作繁琐。实验观察到 ,在稀硫酸介质中 ,锇 能催化溴酸钾氧化靛蓝胭脂红 (IC)褪色 ,由此建立了测定痕量锇 的新方法。该方法具有检出限低 ,精密度高 ,选择性好 ,体系稳定等优点。2　实验部分2 .1　仪器与试剂　 72 2型分光光度计 (山东高密分析仪器厂 ) ;5 0 1型超级恒温器 (江苏实验仪器厂 )。 0 .10mg/LOs 工作溶液 (当天配制 ) :由 10mg/LOs标准溶液用水稀释得到 ;0 .0 1mol/LKBrO3 溶液、0 .0 5 0 %靛蓝胭脂红 (北京化学试剂研究所 …     

靛蓝胭脂红-溴酸钾体系催化光度法测定微量碘

研究了在室温及0．4mol/L H2SO4介质中碘离子对KBrO3氧化靛蓝胭脂红褪色反应的催化作用,建立了一种测定微量碘的新方法。碘离子浓度在0．20－2．0μg/mL范围内与△A呈线性关系,检测限为0．14μg/mL。多数常见离子无干扰。可用于海带中微量碘的测定。     

靛蓝胭脂红共振瑞利散射法测定蛋白质

在pH 2.34的B-R缓冲溶液中,靛蓝胭脂红及蛋白质的共振瑞利散射(RRS)均十分微弱。但两者结合时,形成的复合物能使RRS信号急剧增强,最大散射波长为393 nm。测定人血清白蛋白、牛血清白蛋白、γ-人球蛋白、卵白蛋白的线性范围分别为0.1~3.7、0.08~3.0、0.05~2.0、0.1~2.4 mg/L;相应的检出限分别为24.6、20.7、20.4、25.7μg/L。本法用于人血清、牛奶、豆浆、尿液中总蛋白质的测定,结果与经典的考马斯亮蓝法一致。     

铁-三乙醇胺媒质中靛蓝的间接电化学还原

铁-三乙醇胺(Fe-TEA)可作为媒质用于间接电化学法还原靛蓝.本工作采用循环伏安法研究了靛蓝在Fe-TEA媒质中的电化学行为,比较了石墨、银、镍、不锈钢四种阴极材料的电催化性能,探讨了靛蓝间接电还原的机理.此外,还进行了一组L9(34)正交电解实验,通过正交实验分析了各因素对电流效率的影响.实验结果表明:在Fe(III)-TEA媒质中,以不锈钢网为阴极可实现靛蓝的间接电化学还原,最高电流效率可达44.7%.在实验所设计因素水平范围内,对电流效率影响最大的因素为Fe(III)-TEA媒质浓度.在靛蓝的间接电还原过程中存在一种靛蓝自由基,该自由基能起到靛蓝电还原的媒质作用,在一定实验条件下,该靛蓝自由基的媒质作用可以大于Fe(III)-TEA.     

Nile Blue and Indigo Carmine organic dyes as corrosion inhibitor of mild steel in hydrochloric acid

The inhibiting behavior of Nile Blue and Indigo Carmine organic dyes on mild steel corrosion was evaluated in 1 M HCl solution, separately, by weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy techniques. Results show that the inhibition efficiency (%IE) increases with the increasing concentration of Indigo Carmine up to 9.65 × 10⁻⁰⁵ M (%IE ~ 98) and Nile Blue up to 1.08 × 10⁻⁰⁴ (%IE ~ 75–80). Good agreement was found between the results obtained from the different techniques used. Polarization curves indicate that the inhibition of the both inhibitors is of a mixed anodic–cathodic nature, and Langmuir isotherm is found to be an accurate isotherm describing the adsorption behavior. The inhibition mechanism of the inhibitors involves chemisorption interaction between the inhibitor and the mild steel. The inhibition efficiency for both inhibitors decreased by the rising temperature in the range of 25–55 °C, and these results verified the chemisorption behavior of both the inhibitors.     

Indigo Carmine degradation by hypochlorite in aqueous medium monitored by electrospray ionization mass spectrometry

The degradation of the dye Indigo Carmine by hypochlorite in aqueous solution was monitored by electrospray ionization mass spectrometry in the negative ion mode (ESI(—)‐MS). Hypochlorite was highly efficient in removing the color of aqueous solutions of the dye. ESI(—)‐MS monitoring showed that concomitant with the Indigo Carmine consumption two transient species appeared (detected as doubly charged anions) probably formed via a net insertion of two hydroxyl groups at the exocyclic C?C bond followed by the incorporation of two (mainly) or one oxygen atoms at the indolic rings of the dye. Structures of these products were proposed based on the ESI(—)‐MS/MS data and high accuracy mass measurements. These two transient intermediates quickly decomposed, both in the condensed and in the gas phase, to yield mono‐charged anions. Based on these results, a route for the Indigo Carmine degradation by hypochlorite in aqueous solution has been proposed. Copyright © 2007 John Wiley & Sons, Ltd.     

Studies on the mechanism of Indigo Carmine removal by solvent sublation

Indigo Carmine (C16H8N2Na2O8S2), an anionic dye, was removed from aqueous solution by solvent sublation of Indigo Carmine-cetyltrimethylammonium bromide (CTAB) complex (sublate) into 2-octanol. A stoichiometric amount of surfactant (surfactant:dye=2:1) was demonstrated to be able to remove over 93% IC from the aqueous solution in 5 min. The apparent activation energy of attachment of the sublate to bubbles was calculated as 1.3 kJ/mol. Parameters were considered. At the same time, on the base of the complete transport mechanism, a mathematical model for the dye-surfactant complexation was obtained. Furthermore, the simulation of the mathematical and experimental data was made with good results.     

Non-linear modelling of the adsorption of Indigo Carmine dye from wastewater onto characterized activated carbon/volcanic ash composite

Over the past couple of years, the resurgence of placing an effective and sustainable amendment to combat against the auxiliary industrial entities like Indigo Carmine (IC), remains a highly contested agenda from a global point. The birth of non-linear modelling for these auxiliary entities is also of significant interest in order to avoid loss of some useful information. With the renaissance of activated carbon (AC), the AC prepared from palm kernel shells (PKSAC) and composite prepared by combining the PKSAC and porous volcanic ash (BVA) from the foot of active volcanic mountain of Cameroon will be of significant contribution for ever increasing pollution problems. Non-linear modelling method was used to model the uptake capacity by adsorption process of IC onto PKSAC and PKSAC/BVA composite. Effects of contact time (0–60 min), adsorbent dose, pH of solution and initial dye concentration (10–20 ppm) were studied on the quantity removal of the hazardous IC dye from aqueous solution in a batch experiment. The prepared PKSAC and PKSAC/BVA composite were characterized using Nitrogen adsorption at 77 K (BET), Fourier transform Infrared spectroscopy (FTIR), Sacanning electron microscopy with energy dispersive X Ray (SEM-EDX), and particle size. The optimum IC uptake was 11.025 and 12.642 mg/g for PKSAC and PKSAC/BVA composites adsorbent respectively. Four Isotherms and kinetic non-linear regression models each were used to model the adsorption data. It results that for the isotherm models, the Langmuir and Freundlich isotherm models best fitted the adsorption phenomenon while pseudo-first and pseudo-second order kinetic models well described the adsorption mechanism. Furthermore, the adsorption speed constant (α) of the Elovich kinetic model being higher than the desorption coefficient (β) implies chemisorption was the dominant mechanism in the adsorption process. The composite shows 14.67% higher in retention capacity of the IC dye than the pristine carbon. Conclusively, the expanding of activated carbon/volcanic ash composite represents a potentially viable and powerful tool, leading to the plausible improvement of environmental preservation.     

Use of an oxidation reaction for the quantitative determination of albendazole with Chloramine-T and acid dyes.

One titrimetric and two spectrophotometric procedures have been reported for the determination of albendazole and its tablets. Using titrimetry, the drug was titrated directly with Chloramine-T under acidic conditions using a Methyl Orange indicator. The spectrophotometric procedures involve treating the sample solution with a measured excess of Chloramine-T in an acid medium, followed by an estimation of unreacted Chloramine-T by reacting with a fixed amount of either Methyl Orange or Indigo Carmine dye solution and measuring the absorbance at 510 nm or 610 nm. The stoichiometric ratio, which forms the basis for the calculations in titrimetry as well as the range of the applicability, are reported. The Beer's law range and sensitivity values for spectrophotometric procedures are included. The methods were applied to the determination of albendazole in tablets with satisfactory results.     

Gamma-radiation induced decolorization and degradation on aqueous solutions of Indigo Carmine dye

Cesium uptake by natural zeolite clinoptilolite from Bulgaria was studied using batch technique and model solutions. The optimal conditions of interaction were determined. The pseudo-second-order rate model better describes the kinetic data obtained at different concentrations. The intraparticle diffusion and the surface diffusion models were tested to identify the rate-controlling step. The sites in the structure of clinoptilolite that are preferable for exchange were studied by application of Rietveld structural approach and the sequence of site occupation by cesium was followed. The Langmuir isotherm model provides a good fit of the equilibrium experimental data. The thermodynamic parameters for the system were calculated.     

Study of the Adsorption of Glutathione on a Gold Electrode by Using Electrochemical Quartz Crystal Impedance, Electrochemical Impedance Spectroscopy, and Cyclic Voltammetry

Adsorption of a biological peptide, glutathione, on a gold electrode was studied by using electrochemical quartz crystal impedance (EQCI), electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV) techniques. The time courses of responses of piezoelectric and electrochemical impedance parameters were simultaneously obtained during the adsorption processes of the two forms of peptide, oxidized and reduced glutathione. It was found that the frequency curve due to the oxidized glutathione (GSSG) adsorption exhibited a character of a sum of two exponential functions. For reduced glutathione (GSH), the frequency adsorption curve could be expressed by a first-order reaction kinetic model and the corresponding kinetic parameters at different amounts of GSH were obtained. The heterogeneous charge-transfer rate constants of ferricyanide/ferrocyanide before and after the peptide adsorption were determined by CV and EIS methods, respectively. According to the simple equivalent electric network of the electrochemical interface, the electrochemical impedance parameters were also obtained. The results showed that the proposed method should be found in wider applications in interfacial biochemistry studies since these combined techniques have advantages in real time multidimensional information including electrochemical and electrochemical impedance parameters. Copyright 2000 Academic Press.     

青黛中微量元素含量测定分析

用原子吸收分光光度法测定了青黛中的7种微量元素。结果表明,青黛中含有丰富的人体必需的微量元素和极微量的有害元素镉和铅。