The chromatographic separation of aromatic amines and xylenes isomers represents a big issue in chemical and petroleum industries, owing to their high similarity in terms of molecular sizes, polarity, and boiling points: as a result, commercial columns very often do not allow their complete peak separation. For this reason, several typologies of materials with different structures and properties have been developed and proposed as gas chromatography stationary phases in recent years. Macrocycles and ionic liquid-based chain-typed copolymers have emerged, due to their special chromatographic selectivity and separation mechanisms, resulting from their three-dimensional structures and outstanding thermal stability. Very recently, innovative stationary phases based on functionalized calixarene-polyethylene glycol (C4A-mPEG) [1], and amphiphilic triblock copolymer bonded with benzimidazolium ionic liquid (TCP-Bim) [2] were designed, characterized, and used for GC separations of aromatic isomers. The separation features of the C4A-mPEG stationary phase, resulting from multiple molecular recognition processes with analytes, including π-π, H-bonding, dipole-dipole, and van der Waals interactions, allowed to obtain high-resolution performances for a wide range of compounds and their isomers, especially benzaldehydes, phenols, and anilines. Moreover, compared with 4-tertbutyl calix[4]arene (C4A) and polyethylene glycol (PEG) stationary phases, a higher resolving capability was also observed for the separation of toluidine and xylidine isomers. The separation capabilities of the TCP-Bim columns are attributable to different analyte-stationary phase interaction mechanisms, arising from the particular TCP-Bim structure that combines ionic liquid and copolymer peculiarities, showing stronger retention towards aromatic compounds. The high-resolution capabilities of the TCP-Bim column were also tested with different aliphatic cis-/trans-isomers; the excellent separation performances for analytes with very similar properties demonstrated the good potential of these innovative materials as new classes of stationary phases for high-resolution GC separations. References: 1. Chen, R., Cai, Z., Li, W., Huang, Q., Nardiello, D., Quinto, M., Liu, X., Hu, S., & Sun, T., Chem. Biodiversity 19 (2022) e202200829. 2. Huang, Q., Cai, Z., Chen, R., Zhang, W., Nardiello, D., Quinto, M., Liu, X., Hu, S., & Sun, T., Microchemical Journal 183 (2022) 108084.
ISOMER SEPARATIONS BY INNOVATIVE GAS CHROMATOGRAPHY STATIONARY PHASES
D. Nardiello
;M. Quinto
2023-01-01
Abstract
The chromatographic separation of aromatic amines and xylenes isomers represents a big issue in chemical and petroleum industries, owing to their high similarity in terms of molecular sizes, polarity, and boiling points: as a result, commercial columns very often do not allow their complete peak separation. For this reason, several typologies of materials with different structures and properties have been developed and proposed as gas chromatography stationary phases in recent years. Macrocycles and ionic liquid-based chain-typed copolymers have emerged, due to their special chromatographic selectivity and separation mechanisms, resulting from their three-dimensional structures and outstanding thermal stability. Very recently, innovative stationary phases based on functionalized calixarene-polyethylene glycol (C4A-mPEG) [1], and amphiphilic triblock copolymer bonded with benzimidazolium ionic liquid (TCP-Bim) [2] were designed, characterized, and used for GC separations of aromatic isomers. The separation features of the C4A-mPEG stationary phase, resulting from multiple molecular recognition processes with analytes, including π-π, H-bonding, dipole-dipole, and van der Waals interactions, allowed to obtain high-resolution performances for a wide range of compounds and their isomers, especially benzaldehydes, phenols, and anilines. Moreover, compared with 4-tertbutyl calix[4]arene (C4A) and polyethylene glycol (PEG) stationary phases, a higher resolving capability was also observed for the separation of toluidine and xylidine isomers. The separation capabilities of the TCP-Bim columns are attributable to different analyte-stationary phase interaction mechanisms, arising from the particular TCP-Bim structure that combines ionic liquid and copolymer peculiarities, showing stronger retention towards aromatic compounds. The high-resolution capabilities of the TCP-Bim column were also tested with different aliphatic cis-/trans-isomers; the excellent separation performances for analytes with very similar properties demonstrated the good potential of these innovative materials as new classes of stationary phases for high-resolution GC separations. References: 1. Chen, R., Cai, Z., Li, W., Huang, Q., Nardiello, D., Quinto, M., Liu, X., Hu, S., & Sun, T., Chem. Biodiversity 19 (2022) e202200829. 2. Huang, Q., Cai, Z., Chen, R., Zhang, W., Nardiello, D., Quinto, M., Liu, X., Hu, S., & Sun, T., Microchemical Journal 183 (2022) 108084.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
