Hierarchical functionalized MCM-22 zeolite for trapping tobacco specific nitrosamines (TSNAs) in solution

To enable zeolite to trap bulky environment pollutants such as tobacco specific nitrosamines (TSNAs), we tailored the porous structure of MCM-22 zeolite by desilication to obtain a sample with mesopores centered 3.5 nm, in order to promote the mass transport. The meso-MCM-22 was further functionalized with -SO(3)H group to enhance the efficiency in adsorption of TSNAs. The composites were characterized by XRD and BET methods, and their adsorptive function was assessed in both liquid adsorption of N'-nitrosonornicotine (NNN) and the adsorption of TSNAs in aqueous tobacco-extract solution. Grafting -SO(3)H group on alkaline-treated MCM-22 significantly elevated the adsorption toward nitrosamines, and the resulting composite could reduce above 70% of NNN in dichloromethane solution or 54% of TSNAs in tobacco-extract solution.