Features of a truxene-based stationary phase in capillary gas chromatography for separation of some challenging isomers

• High resolving ability for xylene isomers and di- and tri-PCB isomers.
• Retention for the PCBs related with their dihedral angles.
• High column thermal stability and excellent repeatability.

Herein we report the first example of exploring truxene-based derivatives for gas chromatographic (GC) separations. The fabricated thiophene-functionalized truxene (TFT) column exhibited weak polarity and efficiencies as high as 4000 plates/m for 0.250 mm i.d. columns. TFT column showed preferential retention for halogenated and alkyl benzene analytes, and especially, high resolving capability for the xylene isomers, di- and trichlorobiphenyls (di-CB and tri-CB) isomers. Interestingly, its unique retentions for the latter analytes were found to be closely related with their dihedral angles and the locations of chlorine atoms. This finding on the retention trend has not been reported in GC separations, which may provide a new perspective in elucidating retention behaviours for specific analytes. Moreover, TFT column exhibited high thermal stability up to 320 °C and excellent repeatability. This work demonstrates the promising future of truxene derivatives in the separation science.