THE CHARACTERIZATION OF CLAYS AND CETYLPYRIDINIUMEXCHANGED CLAYS FOR THEIR ABILITY TO ADSORB ZEARALENONE

Abstract

The adsorption of zearalenone (ZEN) onto Ca-montmorillonite (STx-1), Na-montmorillonite (SWy-2), acid-activated montmorillonite (AAM), clinoptilolite and cetylpyridinium (CP) exchanged clays was studied. The results indicated that CP-exchanged clays were more effective than unmodified base clays in adsorbing ZEN, i. e. STx-1 (7.4±2.3 mg/g) < clinoptilolite (7.6±1.1 mg/g) < AAM (10.0±0.0 mg/g) < SWy-2 (11.9±0.4 mg/g), whereas the extent of ZEN adsorption into modified clay products did not follow the order seen in the based clays. The adsorption efficiency of CP-exchanged clays is in the order of CP*STx-1 (56.9±1.1 mg/g) = CP*AAM (56.9±1.8 mg/g) > CP*SWy-2 (47.9±2.6 mg/g) > CP*clinoptilolite (15.5±1.1 mg/g). Three CP-exchanged clays were further
characterized by isotherm studies. The results indicated that the isotherm shapes of CP*exchanged clays exhibited a S-shape. The isotherm plot is concave up to the inflection point and then plateaus, which suggests multiple, specific binding sites and saturation at each site. It is important to rigorously test and thoroughly characterize potential mycotoxin binding agents both in vitro and in vivo to provide an understanding of the mechanism of adsorption, in order to modify or develop adsorbents for enhanced products and multi-mycotoxin binding agents.