Multifunctional magnetic chitosan-graphene oxide-ionic liquid ternary nanohybrid: An efficient adsorbent of alkaloids

A magnetically and recyclable multifunctional nanohybrid adsorbent (IL-Fe₃O₄@SiO₂@CS/GO) with chitosan, graphene oxide and ionic liquid was prepared by glutaraldehyde cross-linking reaction, acylation reaction and directly grafted method. The incorporation of CS, GO and IL could collaboratively enhance adsorption for 5 alkaloids. The Box-Benhnken design was applied to optimize the experimental parameters affecting the extraction efficiency. The adsorption kinetic was further used to describe the adsorption process, revealing alkaloids adsorption was a chemisorption process, which was well represented by pseudo-second-order model. Concerning the equilibrium behavior, the adsorption was multilayer and heterogeneous adsorption that satisfactorily modeled by the Freundlich model. Under optimal conditions, good adsorption capacity for morphine, codeine, ephedrine, amphetamine and benzoylecgonine (7.2, 8.4, 9.2, 5.8 and 11.2 mg g^-1, respectively) were obtained via multiple mechanisms to attain simultaneous extraction of alkaloids. Accordingly, IL-Fe₃O₄@SiO₂@CS/GO nanohybrid adsorbent could be extended as a potential adsorbent for extraction of illicit additives in food samples.