[Ability of bentonite and natural zeolite to adsorb aflatoxin from liquid media].

The adsorption of aflatoxin (AF) B1, contained in aqueous medium or in synthetic medium left after the cultivation of Aspergillus parasiticus NRRL 2999, was studied in two samples of bentonite, two samples of natural zeolite, and three kinds of adsorption coal added to water, to saline, to the blood serum of pigs, to the stomach fluid of pigs or rumen fluid of cows at concentrations of 5 to 50 mg per litre. Unlike retinol-propionate and beta-carotene, AF was readily adsorbable in vitro. The initial concentration of 3.6 mg or 18 mg AFB1 per litre was reduced to 0.3-27% after exposure to 50 g of adsorbent; this reduction was greater when the AFB1 was tested in the cultivation medium and the maximum reduction was recorded when adsorption coals was involved. The effectiveness of zeolite was lower in media containing nitrogen compounds and in those cases when its doses were low. The average AF retention in the adsorbents, calculated after the determination of desorption by chloroform extraction, was 72% of the original content in the medium in the case of adsorption coals, 66% in bentonite, and 60% in zeolite.