Zeolitic imidazolate frameworks (7, 8, 9, and 67) for removal of aflatoxin M1 from raw cattle milk

This investigation demonstrates the applicability of four synthesized and characterized metal-organic frameworks (MOFs), ZIF-7, ZIF-8, ZIF-9, and ZIF-67, for the removal of aflatoxin M1 (AFM1) from cattle milk. Experiments assessed the removal of AFM1 at different concentrations (100 to 1100 ng L^-1). The efficiency of ZIFs for adsorbing AFM1 was affected by the adsorbate concentration, indicating that an increase in AFM1 concentrations of milk samples could result in a decrease in AFM1 removal efficiency. The order of removal efficiency was: ZIF-8 > ZIF-7 > ZIF-67 > ZIF-9. ZIF-8 had the highest removal efficiencies. The AFM1 in the milk sample treated ZIF-8 never exceeded the USFDA maximum safety limit (500 ng L^-1); however, at AFM1 concentrations ≥700 ng L^-1, ZIF-8 was not capable of maintaining the AFM1 concentrations below the limit of the EU and Codex Alimentarius (50 ng L^-1). Hence, some ZIFs can serve as effective adsorbents for removing AFM1 from real samples.