Polarizable polysiloxane stationary phase containing a cyano unit attached to an aromatic side group for highly selective separation of H-bonding and aromatic analytes

Abstract

A new polarizable polysiloxane stationary phase containing a cyano unit attached to an aromatic side group, called CPPP [14.6% 3,4-bis(4-cyanophenyl)-2,5-diphenyl phenyl polysiloxane], was synthesized and used as a stationary phase for capillary gas chromatography (GC). The chemical components of CPPP were characterized by ¹H nuclear magnetic resonance spectroscopy. The stationary phase exhibited excellent film-forming ability and high column efficiency (3852 plates per m) for naphthalene at 120 °C. The thermal stability of CPPP was evaluated by thermogravimetric analysis and column bleeding. Results revealed that CPPP could endure high temperatures up to 370 °C. Moreover, the selectivity of the CPPP stationary phase for H-bonding and aromatic analytes, including Grob test mixtures, fatty alcohols and substituted benzenes, was evaluated. Relying on sensitive dipole–induced dipole, H-bonding and π–π interactions with specific solutes, CPPP showed advantages over current stationary phases for separations of polycyclic aromatic hydrocarbons and aromatic aldehydes. In conclusion, the new CPPP stationary phase with high thermal stability and unique selectivity exhibits great potential for GC separations.