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.     

催化动力学光度法测定痕量钛的研究

本发现以２，２＇－联吡啶作活化剂，痕量钛在硝酸介质中催化过氧化氢氧化甲基橙褪色的指示反应。研究了催化褪色反应的最佳条件和动力学参数，建立了测定痕量钛的新方法，方法的最低检测限为４．５×１０＾－１２ｇＴｉ（Ⅳ）／ｍｌ，测定范围为０－０．２μｇＴｉ（Ⅳ）／２５ｍｌ，用于测定人发中的Ｔｉ（Ⅳ），获得了满意的结果。     

催化褪色光度法测定痕量钛的研究

本发现钛（Ⅳ）在稀硫酸介质中催化孔誉绿与碘化钾、碘酸钾之间的褪色反应，建立了褪色反应速率方程式和测定痕量钛（Ⅳ）的新方法。方法检测限为３．４ ×１０＾－１０ｇＴｉ（Ⅳ）／ｍＬ，测定范围为０～１．０μｇ／２５ｍＬＴｉ（Ⅳ）。用于测定人发中的微量元素钛的含量，获得了满意结果。     

Nafion修饰电极阴极溶出伏安法测定痕量钛

本文采用Ｎａｆｉｏｎ修饰玻碳电极阴极溶出伏安法测定痕量钛。研究了Ｎａｆｉｏｎ膜的有关特性和测定的佳化条件。当富集时间为１ｍｉｎ时，Ｔｉ（Ⅳ）浓度与峰电流在１．０～５０ｎｇ／ｍｌ范围内呈线性关系。本法应用于铝合金和白泥标样中钛的测定，结果满意。     

速差催化动力学光度法同时测定痕量PO_4~(3-)和AsO_4~(3-)

首次基于和对Zr（Ⅳ）－MTB－CTMAB及Zr（Ⅳ）－MTB－CTMAB－LA体系不同的催化作用，建立了同时测量痕量和的速差催化动力学光度分析法。研究了24种共存离子的影响。对与质量比为1～7的标准混合样品进行了测定，相对误差小于10％。     

钛催化十六烷基三甲基溴化铵活化H2O2氧化甲基绿褪色动力学光度法测定痕量Ti（Ⅳ）

基于在稀H2SO4介质中及90℃条件下,痕量Ti(Ⅳ)对十六烷基三甲基溴化铵活化H2O2氧化甲基绿褪色反应有明显的催化作用,据此建立了催化动力学光度法测定痕量Ti(Ⅳ)的分析方法。优化了实验条件。非催化反应(吸光度为A0)与催化反应(吸光度为A)在波长631nm处的吸光度差值△A与Ti(Ⅳ)的质量浓度ρ在0.03～1.50μg/25 mL范围内呈良好的线性关系,检出限为7.488×10-10g/mL。在25 mL溶液中对1.0μg Ti(Ⅳ)标准溶液测定12次,相对标准偏差为1.3%。测定了动力学参数,反应为准一级反应,表观速率常数为5.72×10-4/s,表观活化能为41.78 kJ/mol。该分析方法用于炼钢烧结矿中痕量Ti(Ⅳ)的测定,样品中钛含量与对照值吻合较好,RSD(n=6)为0.18%和0.22%,回收率在98%～101%,符合痕量分析要求。     

动力学光度法测定痕量钛的研究

利用Ｔｉ（Ⅳ）对溴酸钾氧化酸性品红的抑制作用，建立了动力学光度法测定痕量Ｔｉ（Ⅳ）的新方法，检出限为２．９×１０＾－８ｇ／Ｌ，测定范围为０～０．０２２ｇ／Ｌ。用于测定人发中Ｔｉ（Ⅳ）结果满意。     

吸附伏安法测定纯铝中痕量钛

在盐酸溶液中，钛（Ⅳ）与钽试剂（BPHA）络合物在－0．3V（vs．SCE）或开路情况下吸附于玻璃碳电极表面，在－0．3－－0．8V范围内以250mV.s^-1进行扫描溶出，峰电位为－0．57V，钛（Ⅳ）浓度在1－35ng.ml^-1(-0.3V)下富集2min和0.06-2ng.ml^-1（开路富集4min）范围内与峰电流呈良好的线性关系，体系选择好，灵敏度高，操作简单，用于纯铝中痕量钛的测定，重现性好，结果准确。     

痕量硒的催化褪色法测定

研究了在盐酸介质中，以EDTA作掩蔽剂，痕量硒(Ⅳ)强化催化氯酸钾氧化2-(5-硝基-2-吡啶偶氮)-5-二乙氨基苯酚（5-NO2-PADAP）褪色反应及其动力学条件，建立了催化动力学测定痕量硒的新方法。方法检出限为0.0183цg/L Se(Ⅳ)，该法用于测定人发中痕量硒，结果令人满意。     

阻抑二甲基黄褪色反应动力学光度法测定痕量钛

基于乳化剂OP存在下的0．08mol／L H2SO4介质中，痕量Ti(Ⅳ)对KBrO3氧化二甲基黄(DMY)的褪色反应有明显的阻押作用，建立了测定痕量钛(Ⅳ)的阻押动力学光度法，方法检出限为0．21μg/L，线性范围为0～8．0μg/L。结合溶剂萃取分离，用于人发、植物、茶叶及岩石样品中痕量钛的测定，结果与标准值相符。精密度试验以ω(Ti)为10^-6水平的试样检测，其RSD(n=6)≤3．4％。     

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.     

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。     

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。     

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...     

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.     

Synthesis of tetrabenzoporphins of the basis of isoindoline

Chemistry of Heterocyclic Compounds -