DICYANOBIPHENYL POLYSILOXANE STATIONARY PHASES FOR CAPILLARY COLUMN GAS-CHROMATOGRAPHY

The chromatographic performance of newly developed dicyanobiphenyl pol ysiloxane stationary phases were evaluated and compared with the perfo rmance of other polar stationary phases, including the previously repo rted monocyanobiphenyl polysiloxanes. Due to the unique combination of polarizable biphenyl and polar cyano functionalities in the side chai ns of the flexible polysiloxane backbone, and by virtue of their mild liquid crystalline properties, the new stationary phases provide excel lent resolution of a wide variety of analytes, both polar and nonpolar , in both GC and SFC. They can be easily coated and cross-linked in op en tubular columns, and the resultant columns demonstrate excellent ef ficiency and performance at temperatures up to 280-300 degrees C. The new stationary phases exhibit enhanced selectivities for various types of isomeric compounds.