Toxicity of high uranium doses in broilers and protection with mineral adsorbents.

The aim of this study was to determine the uranium distribution and histopathological changes in broiler organs (kidney, liver, and brain) and muscle after 7 days of contamination with high doses of uranyl nitrate hexahydrate (UN), and the protective efficiency of three different mineral adsorbents (organobentonite, organozeolite, and sepiolite). During the 7 days, the UN administration was 50 mg per day, and administration of adsorbents was 2 g per day immediately after UN. In control group where broilers received only UN, histopathological changes such as necrosis of intestinal villi, oedema, vacuolisation and abruption of epithelial cells in renal tubules, oedema and vacuolisation of the cytoplasm of hepatocytes, and dystrophic changes in the neurons of the medulla oblongata were observed. In contrast, when the adsorbents organobentonite, organozeolite, and sepiolite were administered, no histopathological changes were observed in liver and brain. The investigated adsorbents showed the highest protective effects in liver (80-92%), compared to the kidney (77-86%), brain (37-64%), and meat (31-63%).

Influence of natural zeolitic tuff and organozeolites surface charge on sorption of ionizable fumonisin B(1).

Natural zeolitic tuff was modified with 2, 5 and 10mmol M(+)/100g of octadecyldimethylbenzyl ammonium (ODMBA) ions and the products were denoted as OZ-2, OZ-5 and OZ-10. The starting material and organozeolites were characterized by determination of the point of zero charge (pH(pzc)) and by thermal analysis. In vitro sorption of fumonisin B(1) (FB(1)) was studied for all sorbents at pH 3, 7 and 9. The pH(pzc) for the zeolitic tuff was 6.8+/-0.1, while the pH(pzc) for OZ-2, OZ-5 and OZ-10 pH(pzc) was 7.0+/-0.1. The curves pH(final)=f(pH(initial)) suggest that the surfaces of all sorbents are positively charged at pH 3 and uncharged at pH 7 and 9. High sorption of FB(1) by the zeolitic tuff in acidic solution suggests electrostatic interactions between the anionic FB(1) and the positively charged surface. At pH 7 and 9, adsorption of FB(1) is prevented because anionic FB(1) cannot be adsorbed at the uncharged surface. From the pH(pzc) for the organozeolites, it is possible that with lower amounts of ODMBA (OZ-2 and OZ-5), at pH 3, beside interactions between head groups of ODMBA and its alkyl chains and anionic FB(1), electrostatic interactions between positive uncovered surface and anionic FB(1) contribute to the sorption, while at pH 7 and 9 there is only the possibility for interactions between FB(1) and ODMBA. When the zeolitic surface was completely covered with ODMBA (OZ-10), FB(1) sorption was independent of the form of FB(1) suggesting only interactions between ODMBA and FB(1).

Aflatoxin B(1) adsorption by natural and copper modified montmorillonite.

Adsorption of aflatoxin B(1) (AFB1) by natural montmorillonite (MONT) and montmorillonite modified with copper ions (Cu-MONT) was investigated. Both MONTs were characterized using the X-ray powder diffraction (XRPD) analysis, thermal analysis (DTA/TGA) and scanning electron miscroscopy/electron dispersive spectroscopy (SEM/EDS). The results of XRPD and SEM/EDS analyses of Cu-MONT suggested partial ion exchange of native inorganic cations in MONT with copper occurred. Investigation of AFB1 adsorption by MONT and Cu-MONT, at pH 3, 7 or 9, showed that adsorption of this toxin by both MONTs was high (over 93%). Since AFB1 is nonionizable, no differences in AFB1 adsorption by both MONTs, at different pHs, were observed, as expected. Futhermore, it was determined that adsorption of AFB1 by both MONTs followed a non-linear (Langmuir) type of isotherm, at pH 3. The calculated maximum adsorbed amounts of AFB1 by MONT (40.982mg/g) and Cu-MONT (66.225mg/g), derived from Langmuir plots of isotherms, indicate that Cu-MONT was much effective in adsorbing AFB1. Since, the main cation in an exchangeable position in MONT is calcium, and in Cu-MONT both calcium and copper, the fact that ion exchange of inorganic cations in MONT with copper increases adsorption of AFB1 suggests that additional interactions between AFB1 and copper ions in Cu-MONT caused greater adsorption.