催化荧光光度法测定痕量亚硝酸根

1　引　　言亚硝酸根广泛存在于环境、水体、食品等物质中 ,它可与胺类及酰胺类化合物反应生成致癌物亚硝胺 ,因此 ,它是水质、环境、食品等检测的重要项目之一。催化动力学光度法测定亚硝酸根已有不少报道 ,而催化荧光法测定亚硝酸根的报道不多。吡红Ｂ是一种生物染色剂 ,在水溶液中发射红色荧光。作者发现 ,稀磷酸介质中 ,溴酸钾氧化吡红Ｂ使荧光猝灭 ,亚硝酸根对此氧化还原褪色反应具有灵敏催化作用 ,据此建立了测定亚硝酸根的催化荧光光度新方法。该法灵敏度较高 ,选择性好 ,简便快速 ,用于水及蔬菜中痕量亚硝酸根的测定 ,结果满意…     

催化溴酸钾氧化萘酚绿B褪色紫外光度法测定亚硝酸根

亚硝酸根广泛存在于环境、水体、食品中,它可与胺类及酰胺类化合物反应生成致癌物质亚硝胺,因此,痕量亚硝酸根的测定方法研究一直受到重视。目前国内外主要利用偶氮染料的分光光度法。催化动力学光度法[1]测定亚硝酸根等也有报道[2~6],而紫外催化光度法测定亚硝酸根的报道不多。在稀磷酸介质中,溴酸钾氧化萘酚绿B,亚硝酸根对此氧化还原反应具有灵敏催化作用。据此建立了测定硝酸根的催化紫外光度方法。方法灵敏度为1.58×10-6g·L-1,线性范围为0.1~2.0μg/25 mL。1试验部分1.1主要仪器与试剂UV-265型紫外光度计亚硝酸根标准溶液:1.0 g·L…     

催化动力学流动注射荧光光度法测定微量亚硝酸根

基于亚硝酸根离子在硫酸介质中催化溴酸钾氧化罗央明６Ｇ使其荧光强度降低的反应，建立了快速，灵敏，简便的催化动力学流动注射荧光光度法测定亚硝酸根的新方法。     

溴酸钾氧化吡罗红G催化动力学光度法测定痕量NO2^—

研究了在磷酸介质中亚硝酸根催化溴酸钾氧化吡罗红Ｇ而使褪色，建立了催化动力学光度法测定痕量亚硝酸根的新方法，测定范围为０．２－２０μｇ／ｍＬ，检出限为０．２ｎｇ／ｍｌ，用于食品和水样中的亚硝酸根测定获得满意结果。     

橙黄Ⅳ分光光度法测定微量亚硝酸根

亚硝酸根是水质检测和食品分析中重要的测定项目之一。天然水和食品中亚硝酸根的测定主要用分光光度法，较经典方法是基于重氮化偶联反应和亚硝化反应，催化光度法也有不少研究。近年来，亚硝化反应由于方法简便、反应产物具有良好的稳定性和分析性能，重新引起了人们的兴趣。本文研究了在盐酸介质中，橙黄Ⅳ与亚硝酸根的亚硝化反应，建立了以双波长叠加分光光度法测定亚硝酸根的方法。用于环境水和合成水样中微量亚硝酸根的测定，结果满意。     

溴酸钾氧化吡口罗红G催化动力学光度法测定痕量NO-2

研究了在磷酸介质中亚硝酸根催化溴酸钾氧化吡口罗红Ｇ而使其褪色，建立了催化动力学光度法测定痕量亚硝酸根的新方法，测定范围为０．２～２０μｇ／ｍＬ，检出限为０．２ｎｇ／ｍＬ，用于食品和水样中的亚硝酸根测定获得满意结果     

溴酸钾氧化酸性铬深蓝动力学光度法测定痕量亚硝酸根

亚硝酸根是环境中重要的污染物之一,是水质、环境、食品等检测的一个重要项目。催化动力学方法测定痕量亚硝酸根已有较多的报道^[1-6],但未见利用酸性铬深蓝指示物质的报道,酸性铬深蓝是一种配位滴定的指示剂。作者发现在稀疏酸介质中,亚硝酸根对溴酸钾氧化酸性铬深蓝褪色反应有灵敏的催化作用,并研究了该指示反应的动力学条件,建立了催化光度法测定亚硝酸根的新方法。该方法灵敏、简便,可用于水、蔬菜中亚硝根的测定。     

表面活性剂增敏催化光度法测定痕量亚硝酸根

基于稀磷酸介质中,溴化十六烷基吡啶对亚硝酸根催化溴酸钾氧化吡罗红B褪色反应的增敏作用,建立了测定亚硝酸根的表面活性剂增敏催化动力学光度法。加入溴化十六烷基吡啶,灵敏度增大2.2倍。测量亚硝酸根的线性范围为0.005-0.15 mg/L,检出限为0.004/L。用于水及蔬菜中痕量亚硝酸根的测定,结果满意。     

阻抑动力学分光光度及荧光光度法测定微量碘

在稀磷酸介质中,微量碘离子对亚硝酸根催化溴酸钾氧化吡罗红B褪色及荧光猝灭的反应有显著阻抑作用,以此为指示反应提出了测定微量碘离子的阻抑动力学光度和阻抑动力学荧光分析新方法。测定碘离子的线性范围分别为4-200μg/L和3-40μg/L,检出限分别为2.8μg/L和1.6μg/L。用于食品中微量碘的测定,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。     

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 -