1973 Volume 22 Issue 4 Pages 394-398
Those factors affecting the magnitude of the values of K β and K γ which indicate the migration rate of the demixing line of thin-layer (TLC) and dry column chromatography (DCC) have been investigated.
The experiments with TLC and DCC were carried out by using the same adsorbents and developers : the results were compared when the adsorbent was silica gel, alumina, and cellulose powder. Developers used were diisopropyl ether-acetic acid [diisopropyl ether system: (A) 100 : 2.13, (B) various mole ratio], benzene-ethanol (benzene system, 100 : 16.42), water saturated 2-butanol, and chloroform- 1 -butanol-diethylamine [chloroform system: (A) 43 : 6 : 1, (B) 35 : 14 : 1]. In the experiments with TLC, samples (pigments, and 2, 4-dinitrophenyl derivatives of amines and amino acids) were spotted on a site of 2 cm from the lower end of the layer, the developing chamber used was, in most cases, the BN-chamber, and the running distance was 10 cm from the spotting site. The DCC was examined by using a column of inner diameter 1 cm and length 12 cm. The front was detected by the fluorescence under ultra-violet ray (3600 Å) and color of components concentrated on the front. As the factors affecting the values of Kβ and K γr on the silica gel layer, the temperature for development, the thickness of the layer (0.1250.75 mm), the distance of development (015 cm), the activity of the adsorbent (as relative humidity), and the vapor of the developer were studied.
With regards the adsorbents, the Kβ value in the diisopropyl ether system (A) increased in the order of alumina, silica gel and cellulose powder. The slope of the straight line of alumina which can be related with the adsorption isotherm of Freundlich was larger than that of silica gel in the diisopropyl ether system (B) (Fig. 1). The Kβ value in the diisopropyl ether system (A) was not affected by the thickness of layer (Table I). Nearly no effect of the temperature (728°C) on the Kβ and Kγ values was observed in the diisopropyl ether system (A) and in the chloroform system (A) (Table II). However by increasing temperature (1030°C), the Rf value of erythrosine and phloxine B became higher, and the value of ponseau SX and indigo carmine became lower in the water saturated 2-butanol (Table III). The Kβ and K γ values were not affected by the running distance when it is in the range about 13 cm from 5 cm, but they were affected when the running distance is less than 5 cm in the benzene system and in the chloroform system (A) (Fig. 2). When the vapor of the developer was saturated, the Kβ and K γ values became lower in the diisopropyl ether system (A) and in the chloroform system (B), and when the amount of the adsorbed vapor was kept constant, the Kβ and K γ values were nearly constant (Fig. 3, 4). The K β and K γvalues were affected by the activity of the adsorbent in the diisopropyl ether system (A) and in the chloroform system (A) (Table IV), but when the vapor of the developer was saturated, this effect could be decreased (Table V).
