All-hydrocarbon liquid crystalline polysiloxane polymer as stationary phase in gas chromatography capillary column for separation of isomeric compounds of polynuclear aromatic hydrocarbons

Two new and high-purity all-hydrocarbon side-chain liquid crystalline polysiloxane polymers were synthesized by grafting all-hydrocarbon liquid crystal monomers onto a polymethylhydrosiloxane backbone. The two polysiloxane polymers show both smectic B and E mesophases which were characterized by (differential scanning calorimetry and X-ray analysis. As stationary phases, these liquid crystalline polysiloxane polymers were coated on the inner surface of a capillary column (i.d. = 0.32 mm, film thickness d(f) ≈ 0.25 μm) using the static coating method. The capillary column was installed on a GC/MS instrument. We used a standard commercial mixture of 21 species of polynuclear aromatic hydrocarbons (purchased from Supelco Co. and Merck Co.) to test the chromatographic behavior of the coated stationary phase. Test results of the isomeric pair compounds show a better separation resolution than identical tests using the commercial HP-5 capillary column, which is a standard and state-of-the-art analytical tool for the chromatographic resolution of PAHs.