Parametric analysis of oscillatory oxidation reactions

A complete parametric analysis, concerning an overall kinetic model for oscillating catalytic deep oxidation of alcohols, carbon monoxide or hydrogen, is presented. The model contains four parameters.     

Efficient and eco-friendly synthesis of dihydropyrimidinones, bis(indolyl)methanes, and N-alkyl and N-arylimides in ionic liquids

Dihydropyrimidinones, bis(indolyl)methanes, and N-alkyl and N-arylimides were synthesized efficiently under mild reaction conditions in the presence of two types of ionic liquids. In each section, effects of different ILs on the yield of reactions were investigated. The use of ionic liquids offer improvements for the synthesis of title compounds with regard to the yield of products, simplicity in operation, short reaction times and green aspects by avoiding toxic catalyst and organic solvents.     

Identification of soy protein in meat by pyrolysis-high-resolution gas chromatography

Pyrolysis-gas chromatography was applied to the characterization of ground beef and soy protein isolate and its mixtures at the 50, 30 and 10% levels. A cryogenic trap pyrolysis mode was employed and the volatile pyrolysates were analysed by a high-resolution capillary gas chromatograph. Two phenolic derivatives, o-methoxy- and dimethoxyphenol, as well as 2,3-dithiabutane are uniquely observed at a large concentration in the soy pyrolysate. Quantification of these characteristic compounds allow the estimation of the level of soy inclusion in the mixture. This approach effectively denotes soy addition up to the 10% level in comminuted beef.     

Algorithms for high-level data processing in gas chromatography

Computer processing of gas chromatographic data is discussed, with special emphasis on the numerical operations needed. The CHADIC program is described. This program enables optimal separation conditions to be determined and isothermal gas chromatograms to be processed for qualitative and quantitative analysis.     

Separation of C27, C28 and C29 sterols by reversed-phase high-performance liquid chromatography on small particles.

The application of reversed-phase high-performance liquid chromatography to the analytical- and preparative-scale separation of sterols has been evaluated. The capacity factors, k', for a number of compounds chromatographed on a muBondapak C18 (LESS THAN 10 MUM) COLUMN ARE PRESENTED. C27, C28 and C29 sterols and also sterols differing in degree of unsaturation could be readily separated as their acetates in this system. The present reversed-phase chromatographic method is apparently not as selective as silver nitrate-silica gel thin-layer chromatography for the position of unsaturation in the sterol molecule.     

The addition of diazomethane to β-ethynylpyridines

The action of diazomethane on -ethynylpyridines substituted in the pyridine ring or analogous compounds with an alkyl group in place of the acetylenic hydrogen atom has given 3-(pyridin-3-yl)pyrazoles. When the acetylenic hydrogen atom is replaced by an electron-accepting carboxyl group, the polarization of the triple bond interferes with the reaction, which then leads to a mixture of 3- and 4-(pyridin-3-yl)pyrazoles with the simultaneous methylation of the nitrogen of the pyrazole ring.     

Coordination compounds of Co(II), Ni(II), and Cu(II) valerates and benzoates with semicarbazide

Complexes of Co(II), Ni(II), and Cu(II) valerates and benzoates with semicarbazide were prepared. The compounds were characterized by chemical analysis, X-ray phase analysis, IR spectroscopy, diffuse reflection spectroscopy, and thermal gravimetric analysis.     

Structural transformations of silicates upon prolonged grinding

Structural changes in diopside, CaMgSi₂O₆, and wollastonite, CaSiO₃, upon prolonged (up to 84 h) grinding in a mechanic agate mortar under environmental conditions were studied. X-ray phase analysis and specific surface measurements were used to show that the stage of amorphization of the starting substances under mechanical treatment is followed by the formation of a partially ordered phase whose reflexes correspond to reflexes of α-quartz. Possible mechanisms of the structural transformations were discussed.     

Microdétermination quantitative sur papier

Résumé On propose une méthode de dosage de Cu²⁺ en quantités comprises entre 0,3 et 20g sur papier FN-1 imprégné de Zn(C₂H₅OCS₂)₂. Les pH des solutions sont compris entre 2 et 5. Le dosage est effectué à±6,4% près. Sa durée est d'environ 30 minutes.

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Quantitative microdetermination on paper. Microdetermination of copper in the vorm of xanthogenate

Summary A method of assaying copper II in amounts between 0.3 and 20g on FN-1 paper impregnated with Zn(C₂H₅OCS₂)₂ is proposed. The pH of the solutions are between 2 and 5. The assay is ±6.4% accurate and lasts about 30 minutes.

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Zusammenfassung Ein Verfahren zur Bestimmung von Cu²⁺ in Mengen zwischen 0,3 und 20g wurde vorgeschlagen. Chromatographie-Papier FN-1 wird dazu mit einer Lösung von Zinkxanthogenat imprägniert. Das pH der Lösungen wird zwischen 2 und 5 gehalten. Die Ergebnisse sind auf ±6,4% genau. Die Dauer der Bestimmung beträgt etwa 30 min.

     

Photochemical chlorination of 2-trichloromethyl-1,3-dioxolane

The photochemical chlorination of 2-trichloromethyl-1,3-dioxolane proceeds only at the carbon atoms in the 4 and 5 positions. The structures of the resulting 2-trichloromethyl-4-chloro-and 2-trichloromethyl-4,5-dichloro-1,3-dioxolanes were proved by means of the IR spectra and chemical transformations.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1611–1613, December, 1973.