Adsorption Efficiency of Diatomaceous Earth for Mycotoxin PDF

Keywords

sediments, diatomaceous earth, mycotoxin

Abstract

Thirty one diatomaceous earth samples (sediments), belonging to Pliocene-Pleistocene era, taken from different pore holes at different depths from Azraq depression, were obtained from Jordan Authority for Natural Resources. After activation, the samples were tested for their ability to adsorb six potent mycotoxins (Aflatoxin B1, Aflatoxin M1, Sterigmatocystin, Zearalenone, T-2 toxin and Ochratoxin A). Adsorption tests were carried out by placing 0.05 to 0.2 g of the activated sediments into 100 ml water-methanol solution (1:4 v/v), containing a mycotoxin level ranging from 0.25 to 5.0 ppm. The sediments of 45-63 µm dia. showed significant rates of adsorption for all mycotoxins, reaching 100% for aflatoxin B1. Maximum adsorption was achieved with particle size of 45-63 µm, incubated at 25°C for 15 to 25 minutes. Moreover, adsorption efficiency of sediments was found to be directly proportional to the number of diatom frustules (valves). Incubation of solutes for periods longer than 25 minutes, often did not cause significant increase in adsorption of aflatoxins. The sediments manifested significant adsorption of all mycotoxins in the following order: B1 > Sterigmatocystin> M1 > T-2 > Zearalenone and Ochratoxin A.