Poly(3-hexylthiophene) stationary phase for gas chromatographic separations of aliphatic and aromatic isomers

This work describes the investigation of utilizing a chain-typed thiophene-based π-conjugated polymer, i.e., poly(3-hexylthiophene) (P3HT), as the stationary phase for gas chromatography (GC). The P3HT column was statically prepared and investigated for its column efficiency, polarity, separation performance, repeatability and thermal stability. As a result, it showed moderate polarity and column efficiencies of 3260, 3310 and 3790 plates/m for 1-octanol, naphthalene and n-dodecane, respectively. As evidenced, it exhibited high-resolution performance for aliphatic and aromatic isomers, including those critical pairs such as phenanthrene/anthracene and p-/m-benzenediol isomers. Moreover, it displayed stronger retention for alkanes, alcohols and phenols in comparison to the polysiloxane stationary phase with close polarity. Also, the P3HT column had good repeatability and reproducibility with the RSD values less than 0.05% for run-to-run, 0.17-0.54% for day-to-day and 2.7-5.2% for column-to-column, and good thermal stability up to 260 °C. This work demonstrates the promising future of the thiophene-based polymer and its derivatives in separation science.