Quantitative relationship and application of 3‐benzylketoimine metal dichlorides in the analysis of volatile hydrocarbons

Abstract

Quantitative relationship and application of 3-benzylketoimine metal dichlorides in the analysis of volatile hydrocarbonsThe paper concerns the analysis of volatile hydrocarbons on newly designed and produced capillary columns. According to the type of coating used, the columns are of the PLOT type, and according to the adsorbate-adsorbent type interactions they belong to the category of complexation GC. The adsorbent used was silica, whose surface was modified with bonded 2-(3-triethoxysilylpropylimino)-3-(benzyl)-pentanone-4 to change the adsorption characteristics. The presence of the ketoimine group of strongly electron-accepting properties permitted the binding of transition metals. The metal ions are capable of interacting selectively with nucleophilic compounds including olefins. The transition metal ions used for sorbent modification were copper(II) chlorides and nickel(II) chlorides. The supported adsorbent was immobilised by bonding the modified silica to the column walls by a film of poly(dimethylsiloxane). Due to this strategy, the coating was very stable, no sorbent loss from the column was observed and the column could be washed with solvent. Besides exemplary separations, the paper quotes retention parameters of the group of compounds analysed and presents a discussion of the specific interactions between the adsorbate and adsorbent.

Stationary Phases for Complexation Gas Chromatography and Microextraction Methods

“…They have been realized as a result of the synthesis of a series of silica adsorbents with the phases chemically bonded to ketoimino groups differing by the types of substituents and the places of their substitutions. Several works describe the properties of electron‐donor‐acceptor adsorbents obtained by bonding transition metal salts such as Cu (II), Ni (II), and Cr (III).…”

“…The authors of the above papers have focused on the commercial stationary phases. Wawrzyniak initiated quantitative structure‐retention relationship (QSRR) studies on stationary phases modified with ketoimine complexes of transition metals. In his work, he proved that the shape and symmetry of the molecules of unsaturated olefins have an effect on their retention in complexation gas chromatography.…”