摘要:

In this paper a new method of purification of raw mixtures of alkaloids by dialysis of aqueous solutions of their salts through a semipermeable membrane is described. The results obtained by using this method of purification of raw mixtures of alkaloids from plant extracts and mother liquors after crystallization of the major alkaloid have been given. In all cases under investigation this method of purification gave crystalline substances.

ISSN:0037-2366    

DOI:10.1080/01496396808052222

出版商:Taylor & Francis Group    

年代:1968

数据来源: Taylor

摘要:

Sorption isotherms, spectroscopic studies, and chromatographic retention data were used to elucidate the mechanisms involved in the separation of strong electrolytes on polyacrylamide gels. For the most part Bio-Gel P-2 was investigated but some results on the dextran gel Sephadex G-10 are also discussed. On P-2 the primary mechanism is not sieving or exclusion on the basis of size but rather a weak physical sorption of the cations to the gel and probably a hydrogen-bond interaction between the anions and the amide hydrogens. Molecules and ions which are not sorbed on the gel are partly excluded from a fraction of the internal solvent volume which is involved in hydration of the gel matrix and is firmly bound to it. When chromatographing solutions at low sample concentrations on some polyacrylamide gels,Knfalls off drastically. This effect is more pronounced in Sephadex than in Bio-Gel and it has been interpreted as resulting from a Donnan exclusion of anions which arises from a small number of anionic groups attached to the gel matrix. Equations relating elution to the various mechanisms are developed.

ISSN:0037-2366    

DOI:10.1080/01496396808052223

出版商:Taylor & Francis Group    

年代:1968

数据来源: Taylor

摘要:

The fundamental equations for calculating the extent of separation in binary elution chromatographic systems are derived. At a specific instant of time, the elution curve in such systems is characterized by two quantities: the optimum cut-point location and the optimum extent of separation. Equations relating the optimum extent of separation to the resolution and to the extent of separation for a single equilibrium stage are given. A number of figures obtained from computer examples illustrate the use of the theoretical results, A new type of component detector—a mobile detector—is proposed.

ISSN:0037-2366    

DOI:10.1080/01496396808052224

出版商:Taylor & Francis Group    

年代:1968

数据来源: Taylor

摘要:

This presentation is an extension of earlier work (1) in which liquid chromatographic separations of hydrocarbons, alcohols, triglycerides, and surfactants with molecular weights ranging from 100–1000 were made, using columns packed with porous polymeric beads. The fractionation capability of the porous gels was extended to smaller molecules through the development of small porosity gels. The gels separate according to molecular size and are therefore useful for both separation and identification purposes. Since porous gels require no stationary liquid phase, long column life is achieved without a saturated carrier.

ISSN:0037-2366    

DOI:10.1080/01496396808052225

出版商:Taylor & Francis Group    

年代:1968

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:10.1080/01496396808052221

出版商:Taylor & Francis Group    

年代:1968

数据来源: Taylor