Ethyl Carbazole-Grafted Polysiloxane as Stationary Phase for Gas Chromatography

In this work, we synthesized ethyl carbazole-grafted polysiloxanes, namely, ECP-9 and ECP-18, which possessed ethyl carbazole contents of 9% and 18%, respectively. The results of thermogravimetric analysis showed that ECP-9 and ECP-18 polymers lost 2% of weight at 365 °C and 380 °C. The minimum allowable operating temperature for the ECP-9 and ECP-18 was 40 °C. In addition, the ECP-9 and ECP-18 columns were thermally stable at 340 °C and 360 °C. The column average efficiencies of ECP-9 were 2306–3090 plates m−1 for a 10 m column and 2594–3438 plates m−1 for a 30 m column. The column efficiencies of ECP-18 were 2497–3428 plates m−1 for a 10 m column and 2829–3700 plates m−1 for a 30 m column. ECP-9 and ECP-18 as stationary phases exhibited moderate polarity based on the McReynolds constants. Given its specific dipole–dipole, dipole-induced dipole, π–π stacking interactions, and hydrogen bond force with solutes, the ECP stationary phases achieved excellent separation for aromatic isomers, substituted benzenes, polycyclic aromatic mixtures, polycyclic aromatic hydrocarbons, and fatty acid esters with satisfactory peak shapes.