ACTIVATED CARBONS - IN-VITRO AFFINITY FOR AFLATOXIN B-1 AND RELATION OF ADSORPTION ABILITY TO PHYSICOCHEMICAL PARAMETERS

Affinity in vitro tests were conducted of the efficacy of 17 activated carbons (ACs) in binding aflatoxin B-1 from solution. Relationships b etween adsorption ability and physicochemical parameters of the ACs (s urface area, iodine number, methylene blue index, and surface acidity) were tested. Using 5 ml of a 4 mu g/ml aqueous solution of aflatoxin B-1 and 2 mg of an AC, adsorption abilities ranged from 44.47% to 99.8 2%. Four ACs showed very high adsorption abilities, binding more than 99% of the available aflatoxin B-1. in comparative testing five ACs sh owed a greater ability to bind aflatoxin B-1 than hydrated sodium calc ium aluminosilicate (HSCAS). Three ACs also showed high adsorption abi lities (ca. 99%) at increasing aflatoxin B-1 concentrations (50 and 25 0 mu g/ml) whereas HSCAS adsorption ability greatly declined. With the exception of three ACs, aflatoxin B-1 adsorption was significantly co rrelated with all the physicochemical parameters, confirming a close r elationship between molecule trapping and the surface physicochemical adsorption process. The methylene blue index was more reliable than io dine number and surface area in predicting AC adsorptive ability. The results suggested that ACs with a high methylene blue index and low su rface acidity have a very high in vitro affinity for aflatoxin B-1; ho wever, their efficacy in protecting against aflatoxicosis should be ve rified further by in vivo tests.