催化光度法测定微量铜

铜是人体内多种酶的活性成分,以人体的新陈代谢有重要调节作用[1]。因此研究铜的分析方法一直引起人们的关注。关于动力学分析法测定Cu(Ⅱ）已有不少文献报道[2-4],但大多是利用铜催化H2O氧化有机染料褪色为指示反应。罗丹明B具有较大的摩尔吸光系数,用于催化动力学分析其测定灵敏度比一般指示剂更高。本研究发现在硫酸介质中Cu( Ⅱ）对溴酸钾氧化罗丹明B的褪色反应有着强烈的催化作用,据此建立了一种新的催化光度测定微量铜离子的反应体系,可用于一些含铜物质的鉴定。     

催化动力学光度法测定痕量钯

基于乙酸－乙酸钠缓冲溶液（ｐＨ４．７５）中，痕量钯（Ⅱ）催化次磷酸钠还原孔雀绿褪色的反应，研究了反应的最优化条件和动力学参数，建立了一种灵敏度高、选择性好的痕量钯的催化动力学光度分析新方法。方法的检测限为２。２７３×１０＾－７ｇ／Ｌ，线性范围０．１￣０．８μｇ／２５ｍＬ，方法应用于模拟合金试样的测定，取得满意的结果。     

过氧化氢氧化二氯荧光素动力学荧光法测定痕量铜

研究了在氨性介质中，铜(Ⅱ)催化过氧化氢氧化二氯荧光素的褪色反应，建立了动力学荧光法测定痕量铜的新方法。方法的检出限为0．06μg/L，测定铜的线性范围为0．2～4．0μg/L。已用于人发、茶叶和自来水中痕量铜的测定。     

催化还原褪色光度法测定痕量铜的研究

本文在少量氯化钠存在下的磷酸－磷酸二氢钾缓冲溶液（ｐＨ＝２．７）中，以铜（Ⅱ）催化次磷酸钠还原罗丹明Ｂ褪色为指示反应，建立了痕量铜的动力学光度分析新方法，在沸水浴中加热反应１０ｍｉｎ，测定的线性范围在０～０．４０μｇ／２５ｍＬ铜（Ⅱ）回归方程为△Ａ＝１．９７５ｃ＋０．００３，相关系数为０．９９９９，以△Ａ＝０．０１计算得测定下限为０．００５μｇ／２５ｍＬ。方法应用于铅基合金，纯铅粉和标准镁合金中铜     

铜(Ⅱ)-麝香草酚兰-H2O2体系催化分光光度法测定痕量铜

催化动力学分析法是痕量和超痕量分析的有效方法。已广泛用于多种元素的测定。有关测定铜的报道近年来日见增多,铜的新指示反应不断被发现。研究发现。在pH10．0的Na2B2O-NaOH缓冲溶液中,痕量Cu^2 对H2O2氧化庸香草酚兰(TB)褪色有强烈的催化作用。实验条件下,褪色反应速率△A与Cu^2 含量在1．0—40μg/L范围内呈良好的线性关系,     

铜（Ⅱ）催化DBN偶氮胂的褪色反应特性及应用

本文研究了铜（Ⅱ）催化抗坏血酸还原ＤＢＮ偶氮胂的褪色反应特性，测定了反应级数和以应的速率方程，拟定了反应的最佳条件，建立测定铜（Ⅱ）的新方法，其检出限为３．４５×１０＾１０ｇ／ｍＬ，线性范围为０～０．１２μｇ／１０ｍＬ，用于人发中痕量铜（Ⅱ）的测定，结果满意。     

催化动力学光度法测定水中微量锰

１引言研究了锰（Ⅱ）催化亮绿ＳＦ褪色反应的动力学特性。在ＮａＡｃ－ＨＡｃ介质中，锰（Ⅱ）对高碘酸钾氧化该试剂的褪色反应具有强烈催化作用，其褪色反应速率与锰（Ⅱ）的浓度在一定范围内呈良好的线性关系。详细研究了亮绿ＳＦ催化动力学光度法测定微量锰（Ⅱ）的条件，建立了测定微量锰（Ⅱ）的新方法。有关文献中催化动力学光度法测定锰（Ⅱ）的检出限大多为１０－１０ｇ／ｍＬ，本方法的检出限为６．０×１０－１１ｇ／ｍＬ，选择性较好，方法相对标准偏差２．５％，用于测定水样中的锰，结果满意。２实验部分２．１主要试剂和仪器…     

催化动力学光度法测定痕量铜

研究了在氨水 NH4 Cl介质中 ,铜 (Ⅱ )催化H2 O2 氧化偶氮胭脂红的褪色反应条件 ,测定了反应的级数及表观活化能 ,建立了测定痕量铜的新方法。该方法的线性范围为 0～ 12 0ng·ml- 1,检出限为 0 .4ng·ml- 1。用该方法测定水样及人头发中铜 ,结果与原子吸收光谱法一致     

催化褪色光度法测定微量锰（Ⅱ）的研究

本文研究在硫酸介质中，锰（Ⅱ）催化ＥＤＴＡ还原重铬酸银，而使之褪色的新指示反应。确定了催化褪色反应动力学条件，锰（Ⅱ）的浓度在０－０．４μｇ／ｍｌ范围内，工作曲线呈良好的线性关系，检测限为０．０１１μｇ／ｍＬ，该方法用于天然水及污水中锰的测定，获得满意结果。     

抑制-催化褪色光度法测定痕量铬(Ⅲ)

提出一种测定痕量Ｃｒ（Ⅲ）新的抑制－催化动力学光度法。该法基于溴化十六烷基三甲铵于结晶紫在碱性介质中褪色反应的催化作用和Ｃｒ（Ⅲ）对此催化褪色反应的抑制效应。该法用于水样中Ｃｒ（Ⅲ）的测定结果满意。对有关该褪色反应的催化和抑制机理亦进行了讨论。     

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。     

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.     

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.     

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...