Daković Aleksandra, Matijasević Srdan, Rottinghaus George E, Ledoux David R, Butkeraitis Paula, Sekulić Zivko
Institute for Technology of Nuclear and Other Mineral Raw Materials, 11 000 Belgrade, Serbia.
Colloids Surf B Biointerfaces. 2008 Oct 1;66(1):20-5. doi: 10.1016/j.colsurfb.2008.05.008. Epub 2008 May 21.
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.
研究了天然蒙脱石（MONT）和铜离子改性蒙脱石（Cu-MONT）对黄曲霉毒素B1（AFB1）的吸附作用。采用X射线粉末衍射（XRPD）分析、热分析（DTA/TGA）和扫描电子显微镜/能谱分析（SEM/EDS）对两种蒙脱石进行了表征。Cu-MONT的XRPD和SEM/EDS分析结果表明，蒙脱石中天然无机阳离子与铜发生了部分离子交换。在pH值为3、7或9的条件下，对MONT和Cu-MONT吸附AFB1的情况进行研究，结果表明两种蒙脱石对该毒素的吸附率均较高（超过93%）。由于AFB1不可电离，正如预期的那样，在不同pH值下，两种蒙脱石对AFB1的吸附没有差异。此外，还确定在pH值为3时，两种蒙脱石对AFB1的吸附均遵循非线性（朗缪尔）等温线类型。从等温线的朗缪尔图得出，MONT对AFB1的计算最大吸附量为40.982mg/g，Cu-MONT为66.225mg/g，这表明Cu-MONT在吸附AFB1方面更有效。由于蒙脱石中可交换位置的主要阳离子是钙，而在Cu-MONT中是钙和铜，蒙脱石中无机阳离子与铜的离子交换增加了AFB1的吸附，这一事实表明Cu-MONT中AFB1与铜离子之间的额外相互作用导致了更大的吸附。
