Comparative study of aflatoxin B<inf>1</inf> adsorption by Thai bentonite and commercial toxin binders at different temperatures in vitro

• Main Authors: Wongtangtintan S., Neeratanaphan L., Ruchuwararak P., Suksangawong S., Tengjaroenkul U., Sukon P., Tengjaroenkul B.
• Format: Journal
• Published: 2017
• Online Access: https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84962167869&origin=inward; http://cmuir.cmu.ac.th/jspui/handle/6653943832/41996
• Institution: Chiang Mai University

© 2016, Fundacion CIPAV. All Rights Reserved. Thai bentonite (TB) and two commercial toxin binders including commercial bentonite (CB) and activated carbon (AC) were investigated for their adsorption capacities of aflatoxin B 1 (AFB 1 ) at different temperatures in vitro. Each sample of 5 mg/l AFB 1 solution was shaken at 25 ̊ , 37 ̊ and 45 ̊ C for 24 hours, and the supernatants of centrifuged samples were analyzed for concentrations of AFB 1 using a UV spectrophotometer at a wavelength of 362 nm. The results indicated that TB is capable of sequestering AFB 1 from aqueous solutions and had significantly greater adsorption capacities than CB and AC (p < 0.05). The adsorption capacities were then calculated and applied to isotherm equations. The linearized Langmuir and linearized Freundlich adsorption isotherm equations indicated that TB was the best toxin binder for adsorbing AFB 1 as demonstrated by its significantly higher estimated maximum binding capacity (p < 0.05), the distribution coefficient and the heterogeneity factor. The mean adsorptions of AFB 1 on all binders were highest at 25 ̊ C, whereas adsorbed significantly decreased when temperatures were increased from 25 ̊ C to 45 ̊ C (p < 0.05). Furthermore, the results revealed that the Freundlich model presented a better fitted to the experimental data than the Langmuir model. This implied that the adsorption behavior of AFB 1 on these toxin binders represented multilayer/multiple site adsorption on the binders’ surfaces. The results support the conclusion that TB adsorbs AFB 1 in vitro more efficiently than other commercial toxin binders, especially at 25 ̊ C.