Amphiphilic calix[4]arenes as a highly selective gas chromatographic stationary phase for aromatic amine isomers

• Published in: Journal of Chromatography A 2019-09, Vol.1601, p.310-318
• Main Authors: Sun, Tao, Qi, Liran, Li, Weiwei, Li, Yan, Shuai, Xiaomin, Cai, Zhiqiang, Chen, Haipeng, Qiao, Xiaoguang, Ma, Lufang
• Format: Article
• Language: English
• Subjects: Aromatic amine isomers; Calixarene; Gas chromatography; Quantum chemistry calculations; Separation performance
• ISSN: 0021-9673
• DOI: 10.1016/j.chroma.2019.04.068

•Amphiphilic Calix[4]arene (C4A-NH2) as GC stationary phase.•Excellent separation performance for aromatic amine isomers.•Specific retention mainly via multiple interactions and shape-fitting selectivity.•Quantum chemistry calculation was carried out to evaluate the interaction mechanism. Efficient separation of aromatic amine isomers is a challenging issue in chemical industry and environmental analysis. Here we report the use of p-amino-tetradecyloxy-calix[4]arene (C4A-NH2) as a novel stationary phase for gas chromatographic (GC) separations. The statically coated C4A-NH2 capillary column showed a high column efficiency of 4332 plates/m for a 0.25 mm ID column and medium polarity. The C4A-NH2 stationary phase exhibited an excellent separation performance both for aromatic amine isomers and a complex mixture of aliphatic analytes with a wide ranging polarity, showing distinct advantages over the commercial polysiloxane stationary phases via diversified molecular interactions covering H-bonding, π-π, van der Waals interactions and shape-fitting selectivity. The retention mechanisms of aromatic amine isomers on C4A-NH2 column were further investigated by quantum chemistry calculations. In addition, the C4A-NH2 column showed good column repeatability with relative standard deviation (RSD) values of 0.03%-0.07% for run-to-run, 0.10%-0.27% for day-to-day and 2.6%–5.7% for column-to-column, respectively, and thermal stability up to 240℃.