Capturing tobacco specific N-nitrosamines (TSNA) in industrial tobacco extract solution by ZnO modified activated carbon

Adsorption of tobacco specific N-nitrosamines (TSNA) in industrial tobacco extract solution by ZnO modified activated carbon (AC) was deeply studied in order to discern the liquid adsorption. ZnO was coated on AC by wet impregnation and characterized with X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and nitrogen-adsorption–desorption to evaluate its modification on the structure of sorbent. Apart from common tobacco extract solution, the industrial extract solution with a higher TSNA content and viscosity was used to assess the performance of ZnO modified AC with monitoring of LC–MS/MS technique. The influence of TSNA concentration, S/L ratio, adsorption time and recycle index was also systemically studied. To explore whether ZnO modification induces some selective adsorptive sites on AC, elution of TSNA from sorbent and the adsorption of main neutral aroma components in tobacco extract solution were performed. About 80% of TSNA could be trapped in the solution and the ZnO/AC sorbent showed a kind of selectivity for 4-methylnitrosamino-1-3-pyridyl-1-butanone (NNK).