催化动力学法测定痕量硒（Ⅳ）

１引言利用催化动力学光度法测定痕量硒已有报道，但都存在Ｆｅ３＋等一些共存离子干扰等问题。作者通过实验观察到，在盐酸介质中，Ｓｅ（Ⅳ）能强烈催化氯酸钾氧化甲苯胺兰褪色反应，据此建立了催化动力学光度法测定痕量硒的一种新方法。方法具有体系简单稳定，选择性好等特点，检出限为８４ｘ１０－７ｇ／Ｌ，线性范围为０～９×１０－７ｇ／２５ｍＬ。直接用于水；人发、面粉和牛奶等食品样中的痕量硒（Ⅳ）测定，结果较好。２实验方法在两支相同的２５ｍＬ比色管中，一支加入０．５μｇ的标准硒（Ⅳ）工作溶液，另一支不加。然后依次分…     

催化动力学光度法测定痕量硫离子

基于氢氧化钠溶液中，Ｓ~（２－）对Ｈ_２Ｏ_２氧化Ｉ－的反应有催化作用，固定反应时间，将此催化体系与二苯胺碘酸钠氧化显色反应相偶合，建立了催化动力学光度法测定痕量硫离子的新方法，并讨论了其动力学条件。方法灵敏度１．４×１０~（－１１）ｇ／ｍＬ，测定范围１．０～１２．０ｎｇ／ｍＬ。操作简便快速，用于测定天然水及含硫工业废水中的痕量硫离子，结果满意。     

催化动力学光度法测定痕量铜的研究进展

综述了近年来国内外催化动力学光度法测定痕量铜的进展情况。对催化氧化动力学光度法、催化还原动力学光度法、催化荧光光度法、阻抑动力学光度法等几个类别，从反应介质、灵敏度、线性范围等方面介绍了对不同反应体系的研究情况，并对催化动力学光度法测定痕量铜的发展趋势做出预测。     

痕量钒的催化动力学光度法研究进展

以指示物质为线索,综述了近年来国内外催化动力学光度法测定痕量钒的研究情况,从反应介质、灵敏度、线性范围等方面介绍了钒对不同指示物质的氧化(还原)的催化动力学光度法反应体系的研究情况,并对催化动力学光度法测定痕量钒的各体系做出综合分析．     

动力学光度法测定食品中的碘

催化动力学光度法测定痕量碘 ,大多使用Ｃｅ(ＩＶ) -Ａｓ(ＩＩＩ)体系[1 3] 。我们的实验发现在硫酸介质中 ,Ｉ- 能强烈催化高碘酸钾氧化苋菜红的褪色反应 ,在波长 5 2 5ｎｍ处 ,其反应速度与碘离子的浓度之间符合动力学一级反应关系式 ,并且此法灵敏度、选择性均较高。1　实验部分取两支 2 5ｍｌ比色管 ,各加入 2 0ｍｌ浓度为8 0× 1 0 - 3ｍｏｌ/Ｌ苋菜红溶液 ,3 5ｍｌ( 1 0ｍｏｌ/Ｌ)Ｈ2 ＳＯ4,2 0ｍｌＫＩＯ4( 0 2 0ｍｏｌ/Ｌ)溶液。向其中一支加入适量碘标准溶液 ( 1 μｇ/ｍｌ) (吸光度为Ａ) ,另一支不加碘 (吸光度为Ａ0 ) ,用水…     

柠檬酸-罗丹明B体系阻抑动力学光度法测定痕量钴(Ⅱ)

催化动力学光度法以其灵敏高、检出限低,受到人们广泛重视.催化动力学光度法常用分析方法［1］有催化氧化动力学光度法、催化还原动力学光度法、催化荧光光度法、阻抑动力学光度法等.催化动力学光度法其检测限都在 ng·mL-1级,通常用于痕量分析,尤其适用于痕量金属离子测定.催化氧化动力学光度法测定痕量钴已有报道［2-5］,而阻抑动力学光度法测定痕量钴报道较少［6,7］.本文研究发现,在NH3·H2O-NH4Cl （pH=9.5）缓冲介质中柠檬酸对双氧水氧化罗丹明B的褪色反应具有阻抑作用,加入钴(Ⅱ)离子后,阻抑作用明显加强,且阻抑作用与加入的钴（Ⅱ）离子浓度成正比.据此建立了利用钴(Ⅱ)-柠檬酸对双氧水氧化罗丹明B褪色反应的催化阻抑动力学光度法来测量痕量钴的方法.该方法用于VB12药品针剂中痕量钴的测定获得较为满意的结果.     

催化动力学光度法测定痕量钴的研究

本文提出了钴（Ⅱ）催化Ｈ２Ｏ２氧化茜素红Ｓ褪色反应体系的新催化光度法。本方法灵敏度高，选择性好，精密度高（测２μｇＣｏ（Ⅱ）６次，ＲＳＤ＝１．４３％）适用于水样中痕量钴（Ⅱ）的测定。     

催化动力学分光光度法测定痕量铜的研究与应用

评述近年来催化动力学分光光度法测定痕量铜的研究进展,包括催化褪色动力学分光光度法、催化显色动力学分光光度法和阻抑动力学分光光度法,主要探讨各反应体系及其条件、方法的检出限、测定范围、应用等.研究新的高灵敏度指示反应、寻找新的活化剂、提高监测技术的灵敏度、对反应的机理进行研究、将催化动力学分析与其它分析技术相结合将是催化...     

水溶性钯－膦配合物催化1－己烯加氢反应研究

研究了水溶性钯－膦配合物ＰｄＣｌ２（ＴＰＰＴＳ）２催化１－己烯加氢反应，考察了两相催化体系中添加表面活性剂ＣＴＡＢ，膦配体ＴＰＰＴＳ，以及溶液ｐＨ值等对反应的影响，证明了１－己烯加氢反应中有一诱导期．反应中涉及两种催化活性物种．一种是由ＰｄＣｌ２（ＴＰＰＴＳ）２还原生成的低氧化态催化物种，它在一定的ＣＴＡＢ浓度下，可以保持相当的稳定性．另一种是被ＴＰＰＴＳ或Ｈ２还原形成的钯黑．根据ＰｄＣｌ２和ＴＰＰＴＳ反应过程的３１ＰＮＭＲ研究，对ＰｄＣｌ２（ＴＰＰＴＳ）２分子中Ｐｄ被还原和ＴＰＰＴＳ被氧化提出了解释     

动力学光度法测定水果,蔬菜,药物中抗坏血酸

１引　言抗坏血酸是人体不可缺少的营养要素，其测定方法主要有碘量法、２，６．二氯靛酚法。动力学方法测定可以提高灵敏度，但催化光度法应用很少。本文依据硫酸介质中，抗坏血酸作活性剂，钒（Ｖ）催化氨酸钾氧化鸡冠花红的褪色反应，建立了一种测定痕量抗坏血酸的催化光度新方法。用ＥＵＴＡ作为抗坏血酸的稳定剂，有效地抑制了抗坏血酸放置时被氧化，成功地用于水果、蔬菜、药物中抗坏血酸的测定，与碘量法对照，结果吻合。２　实验部分２．１仪器与试剂７２２光栅光度计（四川仪表九厂）；ＣＳ５０１超级恒温器。抗坏血酸标准溶液：１…     

利用手持技术改进测定乙醇分子结构实验

利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。     

Neutral diterpenoids of oleoresins of five species of conifers of Transcarpathia

The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988.     

光谱仪测试范围的扩展

由于石化行业的生产需要，其材质的使用具有多样性和广泛性，经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识，根据光谱仪的测试能力及标样的采集，实现了一个或几个元素测量范围的扩展，并对其测量的影响因素进行了研究。     

Influence of viscosity of medium on processes of oxygen quenching of excited states of mesoporphyrin

The oxygen quenching rate constants for singlet and triplet excited states of the dimethyl ester of mesoporphyrin IX increase with decreasing viscosity of the medium and reach a maximum at a viscosity of approximately 0.4 mPa·sec, after which the rate constants begin to decrease. The drop in rate constant with increasing fluidity of the medium may be related to a nonequilibrium character of the elementary act in the interaction of the reactants in the solvent cage. In viscous media such as isopropyl alcohol, isobutyl alcohol, and isoamyl alcohol, the reaction radius is greater than the sum of the radii of the reacting particles. The long-range character of these processes is due to the relatively weak dependence of the quenching probability on distance.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 161–167, March–April, 1989.     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

物质分配系数的测定实验改进

实验教学目的是从解决实际问题出发,以实验技术训练和实验设计思想培养为目标。介绍了将单一的物质分配系数测定实验改进为综合实验,提高了实验效果及实验资源利用率。     

Effect of the Method of Modification of Zeolite X on Selectivity of Catalytic Methylation of Toluene

Theoretical and Experimental Chemistry - The effect of the method of modification of catalysts based on zeolite X by cesium and magnesium cations (ion exchange and impregnation) on the selectivity...