不同烟草生物质热解释放致香物质的研究

采用烟叶和烟梗为原料,使用热裂解气相色谱法对烟草的燃烧时间、燃烧温度进行控制,精确模拟实际烟草致香物质释放环境,精确捕获、并半定量物质,从而在实验室模拟、分析、研究烟草燃烧物中致香物质的组成和特点。研究分别考察了两种生物质在500℃、550℃下释放的致香物质组成。结果表明,烟梗、烟叶中元素组成中硫、氮两种元素含量低,而C/H比值两种烟草生物质均较高。两个热解温度下烟叶的热解产物中致香物质的含量均明显高于烟梗。升高热解温度均有利于获得更高相对含量的热解成分。烟叶热解产物中烯烃类物质相对含量比烟梗中多,而烟梗热解产物中酚类物质含量比烟叶中多。提高热解温度有利于酮类致香物质含量产生。     

A calculation method to estimate the concentration and elemental composition of organic substances in natural Waters

The possibility of calculating the elemental composition and concentrations of organic substances in natural water based on the results of determining organic carbon and nitrogen and chemical oxygen demand is substantiated both theoretically and experimentally. Three types of substances differing in the electrochemical valence of carbon were among organic substances. The elemental composition of a number of water objects was analyzed. It was found that the concentrations of organic carbon, oxygen, hydrogen, and nitrogen are close to 50, 40, 4–5, and 2–5%, respectively.     

Analytical Chemistry of Phases of Variable Composition and the Principles of Stoichiographic Determination of Such Phases in Multielement Multiphase Samples

The general problems of determining the stoichiometry and content of solid phases of variable composition in multielement multiphase substances are discussed. The possibilities and conditions of application of a reference-free stoichiographic method based on the differential dissolution (DD) of components for the analysis of samples containing spatially homogeneous and inhomogeneous phases are considered. The results of mathematical modeling of the DD process for a mixture of phases of constant and variable composition are presented. These data substantiate the use of the stoichiogram affinity criterion for the identification of spatially inhomogeneous phases of variable composition. Examples of applying the DD method to the phase analysis of various substances containing phases of variable composition are given.     

Prediction of the Quality of Petroleum Bitumens

The common and specific features of quality standard and substandard bitumens were studied by elemental analysis and by determining the yield and composition of toluene-insoluble substances, the composition and concentration of impurities in standard and substandard bitumens, and the group composition of bitumens before and after aging.     

Terpenoids of the needles of Picea abies

The composition of the terpenoids of the neutral petroleum-ether-soluble substances from an isopropanol extract of the needles of the Norway spruce has been studied. The main components of the extractive substances are polyprenol acetates, alcohols with the labdane type of structure, and epimanool and epitorulosol. It has been shown that the terpenoids from the needles differ in composition from the extractive substances of the trunk part of the tree and those from the oleoresins of the sprucesPicea abies, P. ajanensis, andP. obovata.S. M. Kirov Leningrad Academy of Wood Technology. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 168–176, March–April, 1986.     

土壤腐殖质的分析化学研究进展

对土壤腐殖质的分析化学研究进展作了综述。具体包含如下几个方面的内容；土壤腐殖质的组成和结构的研究，土壤腐殖质的起源和形成的研究，土壤腐殖质与土壤中有机，无机物质的相互作用的研究以及有机物料的分解，转化及其对腐殖质影响的研究，同时，对土壤腐殖质的研究中有待进一步用分析化学方法解决的几个问题进行了探讨。     

Determination of Gentamicin Sulphate Composition and Related Substances in Pharmaceutical Preparations by LC with Charged Aerosol Detection

A new, simple and repeatable liquid chromatography method with charged aerosol detection (LC-CAD) for the determination of gentamicin sulphate composition and related substances has been developed. Gentamicin lacks of chromophores, therefore its determination is quite problematic. Using a universal CAD enables to achieve good separation without sample derivatization. Mass spectrometry was employed to confirm the LC-CAD peak profile. The proposed method was validated and applied for the determination of gentamicin sulphate composition and related substances in pharmaceutical preparations.     

Thermodynamics of dissolution of acetoacetyl and 1,1′-bis(acetoacetyl)ferrocene in water-tert-butanol solutions

The polythermal solubility of acetoacetylferrocene and 1,1′-bis(acetoacetyl)ferrocene (bis(acac)Fec) in water-tert-butanol solutions of different composition was studied. The solubility of the substances under study (to a greater extent, for acetoacetylferrocene) increases with rising temperature and alcohol content. Two dissolution mechanisms, the void and solvation mechanisms, were proposed. The thermodynamic parameters of dissolution and transfer of the solute substances from water to the mixed solvent of a certain composition were estimated.     

Chromatographic separation map and incremental relationships in the method of relative analysis of retention under HPLC conditions

It was demonstrated that the correlations between the logarithms of the retention factors for various pairs of substances being linear makes it possible to plot and analyze maps of separation of complex mixtures at various mobile phase compositions on the basis of two measurements at the boundaries of the eluent composition range. Applied to the available experimental data, the relative analysis of retention showed that the use of incremental relationships in the form of the difference between the retention parameters for the corresponding substances at a given mobile phase composition is incorrect. A substantiation of the new method was presented.     

Comparative data on the physicochemical properties of some liquid explosive substances

Summary The composition of the products of explosion does n of depend on the chemical structure of the substances, but is fully determined by the elementary composition of the molecule (C, H, N, O).     

Standardless Analysis of Multicomponent Mixtures of Substances by Time-Resolved Vibronic Spectroscopy

A new approach to the quantitative and qualitative standardless analysis of complex substances based on experimental time-dependent vibronic luminescence spectra (in the UV and visible regions) is proposed. The approach requires no preliminary calculation of absolute intensities for molecular models. It is shown that this analysis can be carried out for both individual substances and multicomponent mixtures, including unknown substances and mixtures of unknown composition. The concentration ranges of mixture components available for the analysis are evaluated, depending on the optical properties of mixtures.     

Theoretical calculation of the optimum separation in thin-layer chromatography

Summary Up to now the optimum composition of a binary mobile phase for separation in thin-layer chromatography has been determined mainly by the method of successive trials. In this paper a simple way is presented to determine the mobile phase composition and the maximum difference in the R_M values of two substances. The equation introduced has been illustrated with examples of adsorption thin-layer chromatography on magnesium silicate. Calculation of the largest difference in the R_M values of two substances in relation to the composition of the binary mobile phase has been compared with the corresponding values determined experimentally. A good agreement of the obtained theoretical data and experimental values has been found.     

Lipid - Carbohydrate Composition of Hibiscus esculenthus

The lipid composition of ripe and green fruit of Hibiscus esculenthus cultivated in Uzbekistan was studied. The fatty-acid composition of pod and seed lipids was determined. Carbohydrate components including water-soluble polysaccharides, pectinic substances, and hemicellulose were characterized.     

Surface treatment of glass-reinforced plastics: Structural study of silane finish layers on the surface of glass fillers. Modification of finishes by transition metal salts

The structure and chemical composition of glass fiber surface treatment substances and their influence on composite materials properties are analyzed.     

Permanent working collection of high purity substances

The work of the collection of high purity substances in the research on the composition of impurities in high purity substances is evaluated. On the basis of the materials available, the present state and future perspectives of the study of high purity substances are discussed.Translated fromIzyestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1512–1520, August, 1994.The authors are grateful to the Russian Foundation for Fundamental Research for financial support (project 93-03-181309).     

A Study of the Composition of Water Vapor Saturated Natural Gas,as Applied to Elucidation of the Nature of Vapor-Gas Thermal Phenomena

The composition of water vapor saturated gases of various temperatures from reserve wells of Yangantau health resort was studied. The dependence of the concentration and composition of organic substances from the vapor condensate and of the extent of thermal oxidative degradation of the shale organic matter on the rock temperature in the heating zone was examined.     

Phospholipids of the seed kernel of sunflowers

Chemistry of Natural Compounds - The qualitative and quantitative composition of the phospholipid complex of the kernels of seeds of the oil-richHelianthus annuus and of the substances associated...     

Phospholipids of the seed kernel of sunflowers

Conclusions The qualitative and quantitative composition of the phospholipid complex of the kernels of seeds of the oil-richHelianthus annuus and of the substances associated with them have been investigated by chromatography in a thin layer of silica gel.The phospholipids consist of four groups of substances: phosphatidylcholines (51.3%), phosphatidylethanolamines (22.6%), phosphatidylinositols (21.8%), and phosphatidic acids (4.3%).The substances associated with the phospholipid complex are cerebrosides and glycolipids, forming two groups in each case.Khimiya Prirodnykh Soedinenii, Vol. 6, No. 3, pp. 292–296, 1970     

有机培肥后土壤水浸提取液成分的研究

土壤浸提液经浓缩后分成元素组成不同的顶层凝结物，中层溶解物和底层沉淀物三部分。浸提液中水溶性有机物和碳酸盐的含量，施用玉米秸秆处理高于对照处理。随着浸提液浓缩的进行，有机质全部形成不溶性的复合物。溶液中的氮以复合物的形式存在，并有一部分随着浓缩的进行而进入固相中。     

Carbohydrates and Lipids of Gleditsia triacanthos Seeds

The carbohydrate and lipid compositions of seeds from Gleditsia triacanthos L. cultivated in Uzbekistan are investigated. Water-soluble polysaccharide (galactomannan), pectinic substances, and hemicellulose are isolated. Their physicochemical properties and monosaccharide composition are found. The content and fatty-acid composition of neutral, glyco-, and phospholipids are determined.