Ammonia as a carrier gas for acidic-basic chromatography

The influence of ammonia as a basic carrier gas on the retention of acidic and basic solutes was experimentally studied. Use of the basic carrier gas (ammonia) leads to an increase in retention of acidic solutes. A simplified theory on the influence of carrier gas basicity influence on the retention of acidic and basic solutes was developed. Contact of an inert gas with ammonia water at ambient temperature can be used to obtain basic humid carrier gas and to improve the chromatographic characteristics of amine's zones.     

Some polishing experiments on copper in a hyperbolic cell

Some polishing experiments have been carried out on copper anodes in a hyperbolic cell designed by Gilmont and Walton, using orthophosphoric acid as the electrolyte. The results obtained have been compared to those obtained in similar experiments in a Hull cell. It has been found that very similar bands of different reflectivity and polishes are found to form in both the cells. These bands shift with time and a study of such displacements has been made. The results are briefly discussed.     

The influence of the carrier gas on retention in capillary gas-solid chromatography

In capillary gas-solid chromatography where interactions between solute and carrier gas and adsorption of the solute on the surface of the adsorbent are considered to be imperfect, it has been shown that chromatographic retention is determined largely by adsorption processes. It has been established that correlation relationships k(P₂)=A k(P₁) + B, where k is the retention factor, and A and B are equation constants, was valid for use of different carrier gases P₁ and P₂. Column efficiency could be improved by use of carbon dioxide. The advantages of using carbon dioxide as the carrier gas were investigated.     

Size effect study in magnetoelectric BiFeO3 system

In this paper, we report for the first time finite size effects on Néel temperature (T _N) of magnetoelectric BiFeO₃ system. Novel wet chemical route has been developed to produce fine particles of BiFeO₃ with controlled size and size distribution. Unlike other oxide systems, lattice volume contraction has been observed with decrease in particle size. The decrease in T _N is co-related to unit cell volume contraction occurring with reduction in particle size.     

Investigation of the role of the carrier gas in capillary gas-solid chromatography

Nonideal interactions of the sorbate and the carrier gas and adsorption of the sorbate on the adsorbent surface in capillary gas-solid chromatography were studied. Chromatographic retention was found to be largely determined by adsorption processes. With respect to the retention coefficients (capacity factors) of a sorbate (k) with different carrier gases (P₁ and P₂), the correlation relationshipk(P₂) =A·k(P₁) +B (A, B are parameters of the equation) is closely obeyed. The advantages of carbon dioxide as the carrier gas were analyzed; the use of carbon dioxide allows the efficiency of the column to be enhanced.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 627–633, March, 1996.     

Use of a moving sorbent for the concentration of heavy impurities

Conclusions A method was proposed, and verified experimentally, for the concentration of heavy impurities using a moving sorbent.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 686–687, March, 1967.     

Ammonia as carrier gas in capillary gas-liquid chromatography.

Influence of helium and ammonia as carrier gases on retention of neutral solutes on polyethylene glycol has been studied theoretically and experimentally. It was shown that the influence of ammonia on the retention varied significantly depending on the solute's nature. For example, the influence is great for C22 n-alkane and it is small for phenol. Taking into account the results obtained by various researchers it makes sense to express an opinion on the expediency of development of gas chromatography operated under the conditions of acidic-basic chromatography.     

Investigation of the effect of the nature and pressure of a carrier gas on retention of organic compounds in capillary adsorption chromatography

The dependence of capacity factors on the pressure of a carrier gas in capillary adsorption chromatography was studied theoretically and experimentally. The equation deduced theoretcally satisfactorily conformed to experimental data.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1981–1983, October, 1995.The authors are grateful to A. A. Lopatkin for useful discussion and critical comments and to the Chrompack company (Netherlands) for the column that was kindly supplied for the work.