EFFECT OF ADSORPTION ON THE RETENTION VALUES IN CAPILLARY COLUMNS COATED WITH OV-225 AND PEG 20M

The effect of adsorption of compounds of different homologous series (n-alkanes, n-alkenes, n-alkynes, n-alkylcyclohexenes, arenes, alkanones) on capillary columns with different contents of polycyanopropylphenylmethylsiloxane (OV-225) and polyethylene glycol (PEG 20M) on retention indices, relative retention and capacity factors was quantitatively studied. The relationships between the retention characteristics and the stationary phase film thickness or capacity factor of a standard solute were established. These correlations permit the prediction of retention data depending on him thickness. It has been shown that among the compounds studied, the adsorption of n-alkanes and n-alkenes is maximum and comprises up to one third of the relative retention on columns with a thin film of PEG 20M.