EVALUATION OF THE POLARITY OF PACKED AND CAPILLARY COLUMNS BY DIFFERENT CLASSIFICATION METHODS

The behaviour of packed gas chromatographic columns filled with 30 different stationary phases was compared by using various polarity indicators: the difference in apparent carbon number of linear alkanes and alcohols with the same retention time, DELTAC, the sum of the first five McReynolds constants, SIGMA(MR)5, Snyder's selectivity parameters, the Kovats coefficient, K(c), and the retention polarity, RP. The correlation between these different systems for polarity evaluation is discussed. The polarity of some wide- and narrow-bore capillary columns, filled with non-polar, polar and modified carbon layer phases, was also evaluated as a function of temperature, in the range 60-120-degrees-C for SIGMA(MR)5 and selectivity parameters and in the range 60-190-degrees-C for DELTAC.