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  • 1
    ISSN: 1612-1112
    Keywords: Thin-layer chromatography ; Chromatographic theory ; Adsorption
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Using adsorption TLC RM values were measured for a number of aromatic compounds on aluminium oxide and silica gels having different specific surface areas, using the following binary mobile phases: benzene+toluene, benzene+carbon tetrachloride and chloroform+carbon tetrachloride. The results are graphically presented and compared with theoretically calculated values. Generally, a good agreement was found between the calculated and measured RM values. The agreement is valid both when the RM values were calculated using experimentally (indirectly) determined partition coefficients or when the coefficients are obtained with help of Ościk's equation [cf. Roczn. Chem.34, 745 (1960) and Chromatographia4, 516 (1971)]. One can assume that in the case of systems in which strong intermolecular interactions are absent, the statically determined partition coefficients of the compounds may be used for the calculation of their RM values.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 13 (1980), S. 215-218 
    ISSN: 1612-1112
    Keywords: Thin-layer chromatography ; Optimum separation ; Binary mobile phase mixtures
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Up to now the optimum composition of a binary mobile phase for separation in thin-layer chromatography has been determined mainly by the method of successive trials. In this paper a simple way is presented to determine the mobile phase composition and the maximum difference in the RM values of two substances. The equation introduced has been illustrated with examples of adsorption thin-layer chromatography on magnesium silicate. Calculation of the largest difference in the RM values of two substances in relation to the composition of the binary mobile phase has been compared with the corresponding values determined experimentally. A good agreement of the obtained theoretical data and experimental values has been found.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 14 (1981), S. 95-99 
    ISSN: 1612-1112
    Keywords: Thin-layer chromatography ; Adsorption ; Binary mobile phase ; Heterogeneity effects ; Chromatographic parameters
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary An equation describing RM values in TLC with a binary mobile phase has been derived and examined by using TLC data. Two different methods have been proposed to determine the chromatographic parameters characterizing energetic heterogeneity of the adsorption system and solute-solvent interactions. These methods differ in the estimation of the mole fractions of solvents in the surface phase. In method I an analytical equation for evaluating these mole fractions is assumeda priori. Method II utilized the excess adsorption isotherm measured for the mobile phae-adsorbent system.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 3 (1980), S. 29-30 
    ISSN: 0935-6304
    Keywords: Thin-layer chromatography ; Mobile phase effects on RM-value predictable ; Binary phase systems ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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