A New Stationary Phase for Capillary Gas Chromatography: Calix[4]resorcinarene Functionalized with Imidazolium Cationic Units

In this work, a novel calix[4]resorcinarene-based ionic liquid (C4RA-2IL) was synthesized, structurally characterized, and statically coated on capillary column as stationary phase for capillary gas chromatography (GC). The column efficiency of the C4RA-2IL column is 3345 plates m−1, which are determined by n-dodecane at 120 °C. Based on its McReynolds constants, the C4RA-2IL column showed moderate polarity. Particularly, the C4RA-2IL column show high separation performance for a wide range of analytes and some difficult separation of meta/para-isomers. Moreover, it exhibited excellent selectivity for critical aromatic isomers of chloroaniline, bromaniline, iodoaniline, toluidine and xylidine isomers and shows advantageous separation capability over the commercial polysiloxane stationary phase. This work presents a promising future of calixarene-based ionic liquid as a new type of stationary phase in GC separations.