甲基绿选择性电极催化电位法测定茶叶中锰

根据在氨三乙酸存在下,Mn2+催化高碘酸根(IO-4)氧化甲基绿的反应,对用甲基绿选择性电极催化电位法测定痕量锰进行了研究.实验表明,该方法灵敏度高,测定锰的线性范围为3.0～100ng/25mL,选择性好,操作简单,温度控制方便.测定了几种茶叶样品中的锰,与原子吸收法比较,结果满意.     

纳米TiO2-Pt修饰电极的制备及其电催化活性

循环伏安;纳米TiO2-Pt修饰电极的制备及其电催化活性     

Coated-wire organic ion-selective electrodes in titrations based on ion-pair formation: Part 3. Determination of cationic triarylmethane dyestuffs

Aqueous solutions of seven cationic triarylmethane dyestuffs can be titrated with sodium tetraphenylborate using as indicator electrode an aluminium wire coated with a PVC membrane plasticized with 2-nitrophenyl 2-ethylhexyl ether or tricresylphosphate. Titrations are possible in unbuffered and buffered media within the pH range 4–10. Characteristic titration data are given for determinations of malachite green B, seto- glaucin 0, brilliant green, fuchsine, methyl violet, crystal violet, and Victoria blue B.     

Study on the supramolecular systems of two basic violets with cyclodextrins by MWNTs/Nafion modified glassy carbon electrode

The electrochemical properties of two basic violets(methyl violet and ethyl violet) at the MWNTs/Nafion modified glassy carbon electrode were investigated.The redox of the basic violets is two-electron and two-proton process,and methyl violet presents stronger electron transfer capacity than ethyl violet.Meanwhile,the inclusion constants of the two basic violets with five CDs were determined by differential pulse voltammetry(DPV).The two basic violets and CDs can form 1:1 complexes. The inclusion capacit...     

Potentiometric determination of the stability constants of the fluoroborate-dye complexes used in colorimetric analysis for boron

An extensive bibliography on the determination of boron by means of tetrafluoroborate-dye complexes is given. The stability constants of the fluoroborate—dye complexes are calculated from potentiometric measurements with an Orion fluoroborate ion-selective electrode, for the following nineteen dyes: methylene blue, methylene green, new methylene blue N, thionine, toluidine blue O, malachite green, brilliant green, crystal violet, fuchsine, methyl green, methyl violet, Victoria blue B, brilliant cresyl blue, Nile blue A, rhodamine B, rhodamine 6G, pyronine Y, safranine T and Janus green B. The solubilities of these dyes have been determined by spectrophotometry.     

Enzyme coated glass pH-electrode: Its fabrication and applications in the determination of urea in blood samples

A new enzyme coated electrode for the determination of urea in blood samples has been developed. It is based on the encapsulation of urease enzyme in the porous silicate matrix by the sol-gel technique on a glass electrode for the purpose of sensing urea in blood samples. Various parameters like the effect of pH, selection of a suitable buffer of appropriate concentration and interference of common substances in blood samples have been evaluated to optimize the conditions for the determination of urea. The electrode can be used for the determination of urea in the concentration range 0.03-30.0 mM in a solution. The detection limit of the present enzyme-coated electrode is found to be 52 μg/ml of urea. The relative standard deviation for the electrode-to-electrode reproducibility is found to be 2.4% for the determination of 0.1 mM of urea (six replicate electrodes). Sol-gel matrix containing immobilized enzyme was stable for about 25 days at ∼4 °C with 80% urease activity. Urea content in various clinical blood samples has been estimated using this electrode and the results are found to be in good agreement with the standard clinical methods as reported in the literature.     

取向碳纳米管/高分子新型复合材料的制备及应用

碳纳米管/高分子复合材料已经被广泛研究, 但长期以来存在一个共同而关键的挑战, 即碳纳米管无规聚集, 结构难以调控, 性能无法满足应用需要. 本工作提出了制备取向碳纳米管/高分子复合材料的一种新方法, 获得块状、膜状、纤维状复合材料, 制备的关键步骤是通过化学气相沉积法合成可纺的高质量碳纳米管阵列. 该方法简单易行, 具有较好的普适性. 由于碳纳米管取向排列, 复合材料具有优异的物理性能, 如碳纳米管取向后复合材料的机械强度和导电率可分别提高一个和三个数量级. 在此基础上, 进一步探讨取向碳纳米管/高分子复合材料作为新型电极在有机太阳能电池中的应用.     

Removal of methyl violet from aqueous solution by perlite

The use of perlite for the removal of methyl violet from aqueous solutions at different concentration, pH, and temperature has been investigated. Adsorption equilibrium is reached within 1 h. The capacity of perlite samples for the adsorption of methyl violet was found to increase with increasing pH and temperature and decrease with expansion and increasing acid-activation. The adsorption isotherms are described by means of the Langmuir and Freundlich isotherms. The adsorption isotherm was measured experimentally at different conditions and the experimental data were correlated reasonably well by the adsorption isotherm of Langmuir. The order of heat of adsorption corresponds to a physical reaction. It is concluded that the methyl violet is physically adsorbed onto the perlite. The removal efficiency (P) and dimensionless separation factor (R) have shown that perlite can be used for removal of methyl violet from aqueous solutions, but unexpanded perlite is more effective.     

Mn-CaO催化剂上甲烷-二氧化碳共活化制C_2烃研究II.催化剂表征及反应机理研究

在Mn-CaO催化剂开展了一系列的表征,包括XRD,XPS,CO2-TPD.结合催化剂评价、表征结果,对催化反应机理进行了推测,指出Mn组分与催化剂的活性相关联而Ca组分的主要作用是提供吸附型的CO2(a)*,反应过程中形成的Mn3+/Mn2+离子对在CO2和CH4的活化过程中扮演了重要角色.     

甲基紫与牛血清白蛋白作用的荧光光谱研究

在pH 7.40的Tris-HC1缓冲溶液体系中,采用荧光光谱法和同步荧光光谱法研究了甲基紫(MV)与牛血清白蛋白(BSA)相互作用.结果表明MV与BSA相互作用两者存在一个结合位点,结合常数(KA)为7.628×103 L/mol,MV与BSA主要发生疏水作用,反应是一个吸热、熵增的自发过程.