Investigations on organo-montmorillonites modified by binary nonionic/zwitterionic surfactant mixtures for simultaneous adsorption of aflatoxin B1 and zearalenone

Abstract

To solve the problem of simultaneous adsorption of polar and weak polar mycotoxins, organo-montmorillonites modified by binary surfactant mixtures (NZMts), including polyoxyethylene ether (OP-10) and lauramidopropyl betaine (LAB-35), were synthesized for the simultaneous removal of aflatoxin B₁ (AFB₁) and zearalenone (ZER). The microstructure, interface and pore structure characteristics of NZMts were investigated through different technologies. The results show that the obtained NZMts modified by binary surfactant mixtures have different structural configurations, higher carbon content and stronger hydrophobicity compared with organo-montmorillonites modified by single surfactant. More importantly, the obtained adsorbents show significant improvements on the detoxification efficiency of both AFB₁ and ZER. The pH has less effect on the adsorption of NZMts compared with the control samples modified by single surfactant, suggesting that NZMts are more stable in different pH environments. In addition, the adsorption mechanisms of NZMts to AFB₁ and ZER were proposed based on the characterizations and adsorption isotherms. It is indicated that NZMts combines with AFB₁ mainly through the hydrophobic interaction and ion dipole action, while with ZER mainly through hydrophobic interaction. The as-received NZMts with more hydrophobic property effectively enhance the adsorption capacities of weak polar and non-polar mycotoxins, providing a new orientation for multifunctional mycotoxin adsorbents.

Keywords: Binary surfactant mixtures; Mycotoxins; Organo-montmorillonites; Simultaneous adsorption.