Kinetics of aflatoxin B<inf>1</inf> and G<inf>2</inf> adsorption on Ca-clinoptilolite

Abstract

The kinetics of aflatoxins B1 and G2 adsorption on Ca-clinoptilolite at pH 2 and 7, in aqueous electrolyte at 37 °C were studied. For both aflatoxins, the adsorption process begins with a fast reaction whereby most of the toxin is adsorbed in the first few minutes. This fast process is followed by the significantly slower process of aflatoxin bonding at active centers of mineral adsorbent. The initial rate method showed that the fast adsorption process of aflatoxin B1 and G2, at both pH values is a first order reaction, while the slow adsorption process of these aflatoxins is a zero order reaction. The adsorption indexes and adsorption rates for both examined toxins were pH dependent. In the investigated initial toxins concentration ranges (500-3000 μg/dm3), high adsorption indexes were achieved (> 80 %).