Aflatoxin B(1) adsorption by natural and copper modified montmorillonite.
Adsorption of aflatoxin B(1) (AFB1) by natural montmorillonite (MONT) and montmorillonite modified with copper ions (Cu-MONT) was investigated. Both MONTs were characterized using the X-ray powder diffraction (XRPD) analysis, thermal analysis (DTA/TGA) and scanning electron miscroscopy/electron dispersive spectroscopy (SEM/EDS). The results of XRPD and SEM/EDS analyses of Cu-MONT suggested partial ion exchange of native inorganic cations in MONT with copper occurred. Investigation of AFB1 adsorption by MONT and Cu-MONT, at pH 3, 7 or 9, showed that adsorption of this toxin by both MONTs was high (over 93%). Since AFB1 is nonionizable, no differences in AFB1 adsorption by both MONTs, at different pHs, were observed, as expected. Futhermore, it was determined that adsorption of AFB1 by both MONTs followed a non-linear (Langmuir) type of isotherm, at pH 3. The calculated maximum adsorbed amounts of AFB1 by MONT (40.982mg/g) and Cu-MONT (66.225mg/g), derived from Langmuir plots of isotherms, indicate that Cu-MONT was much effective in adsorbing AFB1. Since, the main cation in an exchangeable position in MONT is calcium, and in Cu-MONT both calcium and copper, the fact that ion exchange of inorganic cations in MONT with copper increases adsorption of AFB1 suggests that additional interactions between AFB1 and copper ions in Cu-MONT caused greater adsorption.
Daković
Aleksandra
A
Institute for Technology of Nuclear and Other Mineral Raw Materials, 11 000 Belgrade, Serbia. a.dakovic@itnms.ac.yu
Matijasević
Srdan
S
Rottinghaus
George E
GE
Ledoux
David R
DR
Butkeraitis
Paula
P
Sekulić
Zivko
Z
D000327:Adsorption; D016604:Aflatoxin B1 / Q000737:chemistry* / Q000378:metabolism*; D001546:Bentonite / Q000737:chemistry* / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D003300:Copper / Q000737:chemistry* / Q000378:metabolism; D014961:X-Ray Diffraction
D001546:Bentonite; D003300:Copper; D016604:Aflatoxin B1; D002118:Calcium