CHROMATOGRAPHIC SEPARATIONS OF COPPER(II), NICKEL(II) AND PALLADIUM(II) CHELATES OF TETRADENTATE SCHIFF-BASES DERIVED FROM 5-METHYLHEXANE-2,4-DIONE AND 1.1.1-TRIFLUORO-5-METHYLHEXANE-2,4-DIONE

The copper(II), nickel(II) and palladium(II) chelates of the ligands bis(isopropanoyl-acetone)-ethylenediimine (H2PA2en) bis(trifluoroisopropanoyl-acetone)ethylenediimine (H2F3-PA2en) and bis(trifluoroisopropanoylacetone)propylenediimine (H2F3PA2pn) were prepa- md. The results of our thermoanalytical studies indicated that the complexes were sufficiently volatile and could elute from the gas chromatographic columns. Adequate separation of palladium from copper and nickel complexes or H2PA2en were obtained on a ps chromatographic column (3m x 3mm) packed with OV101, 3% on Chromosorb WHP 80-100 mesh size. However, complete separation between copper, nickel and palladium complexes was achieved on HPLC column (200 x 4.6 mm) Si 100, 5mu. The complexes were eluted with binary or ternary mixtures of chloroform, 1,2-dichloroethane and n-hexane. The detection by UV of each of the metal chelate was obtained at the ng levels.