Separation performance of dithienyl benzothiadiazole-based stationary phases for capillary gas chromatography

This work explored the separation performance of two new dithienyl benzothiadiazole (TBT)-based materials, namely 4,7-di(5-allyl-2-thienyl)benzothiadiazole (TBT-AA) and 4-(5-allyl-2-thienyl)-7-(5-dodecyl-2-thienyl)benzothiadiazole (TBT-AC12), as the stationary phases for capillary gas chromatography (GC). The TBT-AA and TBT-AC12 columns exhibited medium polarity and achieved a column efficiency of 3700 plates per m and 3800 plates per m, respectively, by n-dodecane under 100 °C. They showed high-resolution performance for analytes of different varieties and advantageous resolving capability for positional and structural isomers, such as chloronitrobenzenes, dibromobenzenes, cymenes and hexanes, over the polysiloxane stationary phase with similar polarity. Moreover, the TBT-based stationary phases display different retention behaviours from the conventional phase via diversified molecular interactions covering π-π and π-π EDA, halogen-bonding, H-bonding interactions and van der Waals forces. Also, they exhibited good column repeatability with the relative standard deviation (RSD) values of less than 0.12% for run-to-run, 1.8% for day-to-day and 5.0% for column-to-column, respectively. This work demonstrates the good potential of the TBT-based stationary phases for GC separations.