Planar Chromatography of Some Metal-EDTA Complexes on Silica Gel G Layers

The chromatographic behavior of some metal–EDTA complexes on silica gel G thin layers is studied using mixed solvent systems containing dimethyl formamide, tetrahydrofuran, and pyridine. The migration of different metal–EDTA complexes is rationalized in terms of adsorption and solubility in the given media. The effect of the negative logarithm of the equilibrium constant of metal–EDTA complexes on retardation factor values is also evaluated. Some binary and ternary separations are achieved. Experimental Apparatus and materials A TLC apparatus (Toshniwal, India) was used to prepare thin layers on glass plates (18 × 3 cm). The plates were developed in rectangular glass development chambers (20 × 4 cm). Silica gel G, dimethylformamide, tetrahydrofuran, pyridine, ethyl al cohol, acetaldehyde, acetone, acetic acid, methyl acetate, and ethyl acetate were of analytical grade and were used as received from BDH. (England)