METAL-COMPLEXES CHEMICALLY BONDED TO SIO2 VIA BETA-DIKETONATE GROUP IN ANALYSIS OF KETONES

Investigation of the packing for complexation gas chromatography made of 3-(3-trimethoxysilylpropyl)-2,4-pentanedione bonded to silica (Pora sil C) has been carried out. The first modification was proceeded in a nhydrous xylene and the unreacted silane was removed by extraction wit h xylene and hexane. Then the packing was modified by bonding PdCl2, C uCl2 and Cu(acac)2 through beta-diketonate groups. Thus obtained packi ngs were studied to determine their usefulness in analysis of ketones which, having a lone pair of electrons at the oxygen atom, can be invo lved in specific interactions with the electron-acceptor centre. A num ber of retention parameters (k', I, DELTAM(e)) was determined to chara cterize specific interactions of the bonded metal with adsorbate molec ules. Measurements were also performed for the packing with free acety lacetonate groups and for the one free from these functional groups bu t having chemically bonded hydrocarbon (C-8) chains on the surface. Di stinct differences in specific interactions of the adsorbates with the studied packings were found. The absence of a component able to enter into coordination interaction, such as a metal, was evidenced by lowe r values of the retention parameters for the two reference packings. A ttempts were also made at separating mixtures of ketones and the obtai ned results confirmed the usefulness of the studied packings in chroma tographic analysis.