Stationary phase properties of the organic molten salt ethylpyridinium bromide in gas chromatography

Summary The organic molten salt, 1-ethylpyridinium bromide, is suitable for use as a stationary phase in gas chromatography. It has a usable liquid temperature range of 110 to 160°C. It undergoes a single phase transition at 110°C which corresponds to the bulk melting point. Below the melting point the phase may be used as a selective adsorbent, although column efficiency and peak symmetry deteriorate as the temperature is lowered from the melting point. Above the melting point, ethylpyridinium bromide can be used to separate a wide variety of organic compounds retaining strongly those compounds possessing large dipole or hydrogen bonding functional groups.     

Calculations on transitions in singly- and doubly-excited C IV

Wavelengths for transitions in the quartet spectrum of C IV are calculated and compared with recent experimental measurements. Transition probabilities and radiative lifetimes are also predicted for several of the lowest 1s 2snl ⁴ L and 1s2pnl ⁴ L levels up toL=4. In addition, wavelengths and transition probabilities for some recently observed C IV doublet transitions to then=4 level are presented.     

Reactions of 4-(o-carboranyl)pyrylium salts with nucleophilic agents. Synthesis of nitrogen heterocycles with an o-carboranyl substituent

Nitrogen heterocycles, viz., pyridines, pyridinium salts, diazepine, and pyrazoles, with an o-carboranyl substituent were obtained by reaction of 4-(o-carboranyl)-pyrylium perchlorates with nitrogen-containig nucleophilic agents, viz., ammonia, primary amines, hydrazine, and phenylhydrazine. Opening of the pyrylium ring without involvement of the carborane ring occurs under the influence of bases.Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 454–458, April, 1981.     

Application of Carbowax 20M as an open-tubular liquid phase in analyses of nutritionally important fats and oils.

In the first part, the reasons for the choice of Carbowax 20M-terephthalic acid as a liquid phase are indicated and the technique for preparation of columns is descirbed. The ECL of 14 to 24 carbon fatty acids (branched and positional isomers of unsaturated acids) as well as the accuracy of determination of some fatty acids, are presented. In the second part, examples of chromatograms are given as well as tables concerning the composition of various fats: vegetable oils, depot fats, and fats from organs of monogastric species, polygastric species, and fish.     

Peculiarities in the copolymerization of trioxane and epichlorohydrin under the influence of EtB⊖F3 A⊕lEt2

This study deals with the copolymerization of trioxane (TO) and 1-chloro-2, 3-epoxypropane (epichlorohydrin, ECH) catalyzed by EtB^?F₃ A^⊕lEt₂ in toluene. The rate of exhaustion of monomers during copolymerization was measured by gas chromatography. It was established that no homopolymers were formed. The copolymers obtained show a high alkali resistance, indicating a statistical distribution of the ECH in the polymer chain. During the first stages of the copolymerization the ECH is exhausted almost instantaneously, whereas TO is gradually exhausted, finally reaching a certain equilibrium depending both on the quantity of the initial ECH and on the temperature at which the process was carried out. Copolymerization is inhibited at increased ECH levels, and only homopolymerization occurs at a certain critical concentration of ECH.     

Absolute fission yields in the fast neutron induced fission of 233U by track etch combined with gamma-ray spectrometry

The absolute fission yields of twenty seven fission products were determined in the fast neutron induced fission of ²³³U, employing track etch in combination with gamma-ray spectrometry. The total number of fissions was measured by registering the fission tracks on a small strip of lexan, a solid state track detector. The fission products were analysed by gamma-ray spectrometry. The measured yield values were compared to the ENDF/B-VI compilation and show a good agreement.