Abstract
Separation of metal acetylacetonate mixtures by zone melting chromatography (ZMC) was investigated on a 2-methoxynaphthalene column. A ZMC apparatus was the homemade one, with which the zone length was controlled constant at 5.0 mm by hot and cold air blasts. A column of 4.0mm in diameter was placed slantwise by 30°from the horizontal line and molten zones travelled at 27mm/hr downwards along the column. Distributions of the solute components after a ZMC process were determined by atomic absorption spectrophotometry for metals or two-wavelength spectrophotometry for metal chelates.
Distribution coefficients determined by Sorensen's method, ksor, varied with the kind of a central metal atom, though depending considerably upon the concentration of the metal chelate. With an increase in the concentrations of solutes in a mixture, the ksor value of each component varied so as to be closer to each other, and ZMC separation became less efficient.
Relationships between the distribution coefficient and the ratio of the half-peak width to the peak position were numerically evaluated. By use of the relationships an observed ZMC curve was analyzed to afford an effective distribution coefficient, k', which though being as half little as the ksorvalue in magnitude, gave a theoretical distribution curve in good agreement with the observed one.
