The strong acidic cationic exchange fiber (SACEF) was used to adsorb yohimbine from alcoholic solution. Batch experiments were performed to examine the effects of adsorbent dosage, solution pH and temperature in the adsorption process. The thermodynamics and kinetics of adsorption were also analyzed. The optimum yohimbine adsorption onto the SACEF was found at pH = 5 of solution and equilibrium could be attained within 20 min. The equilibrium adsorption data were preferably modeled with the Freundlich isotherm model and the thermodynamic parameters were calculated to be: 11.99 kJ/mol < Δ H < 13.72 kJ/mol, −21.17 kJ/mol < Δ G < −17.87 kJ/mol and 63.18 J/mol K < Δ S < 65.60 J/mol K. The results demonstrated that the adsorption was an endothermic, spontaneous and feasible process of physisorption . Meanwhile, yohimbine adsorption on SACEF fitted well to the pseudo-second-order kinetic model and the adsorption rate was limited by film diffusion. The activation energy Ea was calculated to be 14.39 kJ/mol. Furthermore, the surface morphologies of the SACEF before and after yohimbine adsorption were analyzed by SEM and the adsorption mechanism was discussed by FTIR analysis. SACEF could effectively adsorb yohimbine from alcoholic solution and could be used repeatedly for more than five cycles.
Lei Qin,Jianan Zhang,Hongye Cheng,Lifang Chen,Zhiwen Qi,Weikang Yuan
Deodorizer distillate as a byproduct of vegetable oil refining is an important source of natural vitamin E. Simple and green extraction can be employed to recover vitamin E from deodorizer distillate, and its performance strongly relies on the solvent used in the process. In order to screen an imidazolium-based ionic liquid (IL) as entrainer, a methodology integrating theoretical and experimental evaluations was applied. ILs composed of 47 types of anions were first investigated by COSMO-RS to figure out the most promising one, and the effect of the alkyl chain on the imidazolium ring was addressed by experiments. The IL [C6MIm]Ac was finally determined as the most promising solvent with the selectivity of 108.23 and the partition coefficient of 8.182 for α-tocopherol. The liquid–liquid equilibrium data and the extraction result for corn oil deodorizer distillate indicate its superior performance for the extraction process dealing with a low concentration of vitamin E.