THE USE OF KOVATS COEFFICIENTS IN GAS-CHROMATOGRAPHY AND CLASSIFICATION OF 200 NON-MCREYNOLDS STATIONARY PHASES

General polarity, Sigma MR, polarity index, PI, retention polarity, RP, mean selectivity index, Sigma I*, and Kovats coefficients, K-c, at 120 degrees C, for 200 non-McReynolds stationary phases using Apolane-87 as standard have been calculated. A Table arranged in increasing sense of the polarity defined by the previous criteria is built up, so that the polarity of a given stationary phase can be quickly ascertained provided its K-c value is known, which is, if the column is available, as easy as to chromatography an n-alkanes mixture. The correlation between polatiry and K-c for 116 stationary phases allows the calculation by means of empirical equations of K-c values, without actually preparing the chromatographic column.