Effect of intramolecular reaction on elution of methyl α,β- thioglycidates in gas chromatography

Conclusions The esters of methyl-substituted,-thioglycsdic acids have the same inversion of the exit as the corresponding ester derivatives. The elution order is determined by the intramolecular reaction of the carbomethoxyl groups with the substituents. The obtained data can be used to confirm the structures of the studied compounds.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2139–2140, September, 1973.     

Use of equivalent isothermal retention index for identification in gas chromatography with linear temperature programming

Conclusions The equivalent isothermal index which the authors proposed earlier enables substances to be identified reliably under conditions of gas Chromatographic analysis with linear temperature programming.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 679–680, March, 1970.     

Effect of time and temperature on the preparation of pyrazines in model reactions of the synthesis of aroma-forming substances

The qualitative and quantitative compositions of pyrazines that form in model glucose—ammonia and glucose—ammonia—leucine reactions in a glycerol medium were studied. Reaction conditions were found that ensure the synthesis of 23 alkylpyrazines in total concentration 6 g/kg. The obtained mixture of pyrazines is promising for use in the development of food aroma-forming substances.Institute of Food Substances, Russian Academy of Sciences, 117813 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 7, pp. 1628–1635, July, 1992.     

Modern trends in the investigation of flavor components

The methodological aspects of flavor chemistry — a new branch in the chemistry of food substances — are discussed. The thermodynamic characteristics of the subjects under investigation are described. The main principles of structural organization during the investigation of the flavor components in complex mixtures in the range of 10^–5-10^–14 g/g are formulated. Examples of the research are given.From a paper presented at the Joint Scientific Session of the Departments of Physical Chemistry and Technology of Inorganic Materials and General and Technical Chemistry.Institute of Food Substances, Russian Academy of Sciences, 117813 Moscow. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 6, pp. 1257–1269, June, 1992.     

Inequality of temperature increments ofn-alkane homologs as one of the reasons for the nonlinear variation of sorption parameters of substances in temperature-programmed gas chromatography

GC behavior of C₆-C₁₇ n-alkanes has been investigated at different temperatures of isothermal analysis and under temperature programming conditions using two capillary columns coated with OV-101 and OV-351 stationary phases. Temperature increments have been calculated for the homologs and their inequality has been demonstrated for each member of then-alkane series. It was shown that the nonlinear individual temperature variation of the energy of dispersive interaction ofn-alkane homologs with the stationary phase, which was observed under isothermal conditions, may be one of the main reasons for the nonlinear change in sorption parameters ofn-alkanes in temperature-programmed gas chromatography.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 642–645, April, 1994.The present work was carried out with the financial support of the Russian Foundation for Basic Research (Grant 93-03-4969).