CHEMICALLY BONDED CHELATES AS SELECTIVE COMPLEXING SORBENTS FOR GAS-CHROMATOGRAPHY .6. MODIFICATION OF SILICA WITH NICL2 AND COCL2 VIA BETA-DIKETONATE GROUPS

Results are presented of studies of new types of packings for gas chro matography which contain nickel(II) and cobalt(II) chlorides and nicke l(II) acetylacetonate chemically bonded via beta-diketonate groups to a silica surface. Taking into account the ability of the metals in the chlorides and acetylacetonate to interact with compounds showing elec tron-donor properties, the study was performed using such adsorbates a s aliphatic linear and branched hydrocarbons. The study allowed the de termination of the influence of structure and configuration of adsorba te molecules on their retention and the definition of the usefulness o f thus prepared packings in chromatographic analysis. The obtained res ults point to selectivity of the packings to the compounds which conta in pi electrons. Moreover, to determine the influence of the type of f unctional group bonded with hydrocarbon chain of a given silane on cha rge-transfer interactions, the obtained results were compared with tho se for the packings in which nickel(II), cobalt(II) chlorides and nick el(II) acetylacetonate were bonded with silica via diphenylphosphine g roups.