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

The behaviour of packed gas chromatographic columns filled with 30 dif ferent stationary phases was compared by using various polarity indica tors: the difference in apparent carbon number of linear alkanes and a lcohols with the same retention time, DELTAC, the sum of the first fiv e McReynolds constants, SIGMA(MR)5, Snyder's selectivity parameters, t he Kovats coefficient, K(c), and the retention polarity, RP. The corre lation between these different systems for polarity evaluation is disc ussed. The polarity of some wide- and narrow-bore capillary columns, f illed 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-deg rees-C for DELTAC.