Adsorption of deoxynivalenol by pillared montmorillonite

Abstract

Deoxynivalenol (DON) is found widely in foods and feeds that are contaminated with mildew and is one of the most harmful mycotoxins, threating not only human health but also impacting animal husbandry. Various physical, chemical and biological detoxification strategies have been applied in the past to reduce mycotoxin contamination. As a practical and economic method, addition of montmorillonite (Mt) offers the potential to eliminate mycotoxins, especially aflatoxin B1 (AFB₁) and zearalenone (ZEA). Our study aimed to control DON, for the first time, using environmentally friendly Mt, modified with aluminum, iron and titanium via a pillaring effect to enlarge interlayer spacing. The materials were characterized using XRD, FTIR, SEM, EDS and BET. Spacing of the pillared Mt layers was shown to exceed that of raw Mt and could be tuned using the pillaring reagents (Al, Fe and Ti, 0.01 to 2.00 eq. relative to the cation exchange capacity of Mt). Adsorption of DON by pillared Mt was investigated using UPLC-MSMS (at pH 2.0 and 6.8). The results demonstrated that the adsorption ratios of 1.00-Al-Mt, 0.50-Fe-Mt and 1.00-Ti-Mt were 23.6%, 14.7% and 23.4%, respectively at pH 2.0 and 27.1%, 21.8%, and 27.4% correspondingly at pH 6.8 when added at 1.0 mg, which is 3-4 times higher than raw Mt (6.3-6.8% at pH 2.0 and 7.3-8.1% at pH 6.8). It was also found that with increased addition of pillared Mt (2.5 mg), the adsorption ratio approached 35%. The time for reaching equilibrium was approximately 120 min. These results demonstrated that Mt after pillaring modifications with Al, Fe and Ti can have potential for the control of DON in foods and feeds.

Keywords: Adsorption; Deoxynivalenol; Detoxification; Montmorillonite; Pillaring.