摘要:

Resolution and resolution-per-unit-time have been studied for columns from 4 to 21 mm i.d. The effects of sample size, particle diameter, and linear flow rate were determined. Greatest resolution was obtained for the largest diameter column, and it was attributed to a loading effect. In a related study, efficiency was examined as a function of column diameter for a constant amount of gel and a constant retention time. The narrower columns gave more plates, but their HETP values were also greater.

ISSN:0037-2366    

DOI:10.1080/01496397108066948

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

A general framework for the development of separation science is proposed which links the criterion of merit via an effective transport equation to the molecular basis of separation processes.

ISSN:0037-2366    

DOI:10.1080/01496397108066949

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

Resolution refers to the separation between two components of a mixture and no more (at any one time). The definition must be unidirectional since the separation between two components may not be mutually good. New indices of resolution are proposed, based upon these principles.

ISSN:0037-2366    

DOI:10.1080/01496397108066950

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

Cation exchange equilibrium distribution coefficients (A) with Amberlite IR-120 have been determined for 20 metal ions in media consisting of mixtures of 0.1MHNO3and varying concentrations, viz., 0.01, 0.05, 0.25, and 1.2M, of ammonium acetate. The metal concentrations were so chosen that the ratio of total amount of cation to total resin capacity ≈ 0.4, sufficient to ensure exchange. The values of separation factors of various metal ion pairs have also been evaluated, and separation possibilities for ions in a number of binary and ternary mixtures have been proposed.

ISSN:0037-2366    

DOI:10.1080/01496397108066951

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

Dianin's compound has been found to exhibit a marked selectivity when clathration occurs from mixtures of hydrocarbons in the C5–C10range. X-ray investigations of clathrates formed from single hydrocarbons show that unit cell dimensions vary only slightly according to the guest component and that small changes in intensity of the diffraction patterns occur. Both the mole ratio (Dianin's compound:guest) and selectivity (composition of hydrocarbon component of clathrate) depend upon the rate of crystallization of Dianin's compound from solution. Under comparable conditions of crystallization, studies with binary blends have shown that the ratio of components in the guest is proportional to the ratio of components in the solution from which clathration occurred. The ease of clathration of a component in Dianin's compound relative to a reference component is termed the relative accommodation factor. Usingn-heptane as the reference hydrocarbon and crystallizing Dianin's compound from equiweight multicomponent mixtures containingn-heptane, relative accommodation factors for many C5–C8paraffins, a few naphthenes and olefins, and a number of C6–C10aromatic hydrocarbons have been obtained. With paraffin hydrocarbons selectivities are in accord with those expected from the known dimensions of the cage. Aromatic hydrocarbon selectivities, however, follow a more complicated pattern, and it is possible that with less flexible structures of this kind ``trapping'' during the formation of the cage plays a more dominant role. Various applications of Dianin's compound are discussed, and it is suggested that the basic structure should be sufficiently stable to allow some modification so enabling ‘tailor-made’ host compounds to be synthesized for specific separations.

ISSN:0037-2366    

DOI:10.1080/01496397108066952

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

The distribution of18O and13C isotopes in a chemical exchange system of carbon dioxide and amine carbamates has been studied. A comparison of isotope separation by 15 amines shows little dependence on the nature of the amine. Effect of amine concentration indicates that diffusion of the reacting species plays a significant role in these systems. This is in conformity with our observation that the viscosity of the amine solutions saturated with carbon dioxide increases rapidly with amine concentration.

ISSN:0037-2366    

DOI:10.1080/01496397108066953

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

Enrichment of13C by the exchange of carbon dioxide with its amine carbamates in nonaqueous solvents has been further studied. Optimum operating conditions for the fractionation of13C in a packed countercurrent column have been determined. A comparison of the method with other competitive methods indicates that the process is fairly attractive at its present stage of development.

ISSN:0037-2366    

DOI:10.1080/01496397108066954

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

Reversible changes in gas-chromatographic peak shape and retention time were produced by applying an electric field across a capillary column that employed a liquid crystal as a stationary phase. In general, applied potential caused peaks to be retained longer and to be more nearly symmetrical in shape. The behavior of a variety of substances has been studied over a range of temperatures.

ISSN:0037-2366    

DOI:10.1080/01496397108066955

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue.

ISSN:0037-2366    

DOI:10.1080/01496397108066947

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor