Study On Adsorption Of Mycotoxin By Modified Montmorillonite

Mildew is a natural phenomenon,which occurs mostly in food or feed.The main cause of moldy growth is the proliferation of mold under suitable temperature and humidity conditions.After the food or feed is contaminated by mold,it will produce a variety of harmful mycotoxins,endangering human’s health and the economic development of animal husbandry.Therefore,how to reduce the various damages caused by mycotoxins has gradually become one of the hottest research areas nowadays.Addition of modified montmorillonite as adsorbent to adsorb mycotoxins is an economical and environmentally friendly and efficient method.A variety of modified montmorillonites were prepared in this study,and their adsorption to mycotoxin-zearalenone(ZEA)was detected by ultra performance liquid chromatography-triple quadrupole mass spectrometer(UPLC-MS/MS).The results are as follows,1.A series of modified MMTs were prepared using four types of modifiers(long chain quaternary ammonium salts,short chain quaternary ammonium salts,non-quaternary ammonium salts,and hydrochloric acid additives)and montmorillonite suspension with heating and stirring.After that,the modified montmorillonite was characterized by FTIR and XRD.It was found that the long-chain quaternary ammonium salt had the best modification effect on montmorillonite,which could increase the spacing of the montmorillonite layer obviously;In the other three types of modifiers,due to the absence of cations,some is difficult to exchange cations with the montmorillonite layer,so the modification effect is the worst;while the other modifiers have cations that can exchange cations with the montmorillonite layer,due to the smaller size of the molecules,the increase of montmorillonite inter-layer spacing is poor.2.Various modified montmorillonites were added to the ZEA aqueous solution and stirred at 37℃ for adsorption experiments.After that,the method using external standard was used to quantitatively analyze the sample in the mode of multiple reaction monitoring(MRM).It was found that in the above four types of modified montmorillonites,long-chain quaternary ammonium salt-modified montmorillonite has the best adsorption effect on ZEA,and the maximum adsorption rate is close to 100%while the non-quaternary ammonium salt-modified montmorillonite is below 10%.As for the short chain quaternary ammonium salt modified montmorillonite,the adsorption effect is the best when thiamine hydrochloride is used as modifier.The maximum adsorption rate is close to 30%;In hydrochloric acidified additives modified montmorillonite,HLC modified montmorillonite had the best adsorption effect,and its maximum adsorption rate was about 65%.3.The kinetics of adsorption and desorption of ZEA by long-chain quaternary ammonium salt-modified montmorillonite were studied.The adsorption of long chain quaternary ammonium modified montmorillonite ZEA exceeded 90%at 0.5 h,and the adsorption rate remained at 90-100%within 3 h afterwards.It can be found that the adsorption rate of ZEA by long chain quaternary ammonium salt-modified montmorillonite is very fast and quickly reaches the equilibrium state.In contrast,the desorption rate of long chain quaternary ammonium salt-modified montmorillonite to ZEA was less than 8%for up to 11 h.Therefore,the adsorption of ZEA by modified montmorillonite was relatively stable.