The simultaneous use of solute vapor pressure and geometry in multidimensional capillary gas chromatographic separations of polychlorinated biphenyls.

The separation of coeluting congeners of Aroclor 1242, 1254, and 1260 on a DB-1 (low polarity) capillary gas chromatographic (GC) column is achieved when cuts of those peaks are transferred onto a smectic liquid crystalline column, which is commercially available. This procedure requires the use of a gas chromatograph equipped with two independent ovens for optimizing the temperature conditions of each column. Excellent base line separations are achieved on multicuts, up to six, of the same injection. This unique multidimensional/multimodal capillary GC system, in which the two separation modes of vapor pressure and molecule geometry are employed, is a powerful analytical technique for the separation of complex organic mixtures.