Analytical performances of two liquid crystals and their mixture as stationary phases in capillary gas chromatography.

Comparative gas chromatographic applications of two new liquid crystals called LCa and LCb and their equimolar mixture LC(a+b) were investigated. The thermal properties of LCa, LCb and LC(a+b) were established with differential scanning calorimetry (DSC) and polarizing microscopy. Differential scanning calorimetry of LC(a+b) showed that the melting or clearing temperature was intermediate between the corresponding temperatures of the pure compounds. Polarizing microscopy showed that the liquid crystal phase of A + B was nematic. The chromatographic separation abilities LCa, LCb and LC(a+b) were studied using fused silica capillary columns. Interesting analytical performances were obtained: isomeric separation of aromatics, polyaromatics, phenols.