FAST EVALUATION OF THE POLARITY OF GAS-CHROMATOGRAPHIC COLUMNS USING THE DIFFERENCE IN APPARENT CARBON NUMBER OF LINEAR ALKANES AND ALCOHOLS WITH THE SAME RETENTION

A method for the measurement of the polarity order of gas chromatographic columns (liquid-packed, porous polymer beads, capillary) which does not require reference to standard phases and many probes, is suggested. The method is based on DELTAC, i.e. the difference in apparent carbon number of linear alkanes and alcohols with the same retention time. The graphical measurement or mathematical calculation of the horizontal distance between the straight lines obtained by plotting the logarithm of the retention of linear alkanes and alcohols as a function of their number of carbon atoms allows the importance of hydrogen bonding with respect to the dispersion forces to be evaluated. All the retention data (adjusted retention times and volume, relative retention, adjusted, net and specific retention volumes) can be used for the calculations. The method is useful for the determination of the change in polarity of mixed or serially linked columns, for the evaluation of the performance of porous polymer beads with respect to liquid stationary phases and for the comparison of packed and bonded-phase capillary columns when polyglycol or polydimethylsiloxane phases are used.