Comparison of Analytical Properties of Two Liquid Crystalline Stationary Phases by Capillary GC

Two related novel liquid crystals used as gas chromatographic stationary phases were evaluated for their analytical properties and separation capabilities, 2-(1-ethyloctyloxy)-4-(4′-(4-butoxybenzoyloxy)-benzoyloxy)-4′-ethyl-azobenzene (LCC) and azo-(4-ethylbenzyl)-3-(2-(1-ethyloctyloxy)-4-(4-(4-butyloxybenzoyloxy)benzoyloxy)pyridino (LCN). The thermal properties of LCC and LCN were established with differential scanning calorimetry and polarizing microscopy. The comparative study of the retention behavior for the both liquid crystals was also reported. The study of the chromatographic performance of a column coated with liquid crystals in the solid, nematic and liquid state was done using a series of appropriate solutes. The mesogenic compounds exhibit interesting separation for some positional and geometrical isomers in aromatic hydrocarbons, phenols, volatile aromatic compounds and polyaromatic hydrocarbons.