Study On Simultaneous Determination Of Multi-Mycotoxins In Grain By LC-MS/MS

A variety of mycotoxins are widely distributed on the earth. It is very easy for the agricultural products and their processed products to become contaminated by mycotoxins. And mycotoxins can enter our food chain that could cause harm to humans and animals, if we and animals are fed on the contaminated food. It is difficult to detect the multi-mycotoxins at the same time because of thier different physical and chemical properties.A rapid and sensitive method was developed to determine9mycotoxins (Deoxynivalenol, Aflatoxins B1, B2, G1and G2, HT-2and T-2toxin, zearalenone and Patulin) simultaneously by high performance liquid chromatography-electrospray-tandem mass spectrometry (LC-ESI-MS/MS). And a suitable extraction and purification method for the LC-ESI-MS/MS determination of four aflatoxins has been optimised by using solid phase extraction (SPE) method, which used the new SPE adsorbents.In this study, we mainly studied liquid chromatography-electrospray-tandem mass spectrometry conditions in order to enhance the response of multi-mycotoxins. The analytes were separated by Zorbax Elipse XDB C18column (2.1±150mm i.d.,3.5μm), and eluted with water (A) and methanol (B) by gradient elution. There was a good liner relationship within the rage of10-500μg L-1, the regression line coefficients of determination (R2>0.9994) of9mycotoxins were obtained, and the relative standard deviations were2.05%-5.49%.The SPE column was prepared with new SPE adsorbents by covalently binding carboxyl grapheme sheets to silica. A number of parameters of SPE methods, including pH, eluent and its volume, were carefully optimized to improve the purification efficiency.The SPE-LC-ESI-MS/MS method of has been optimized to determine4aflatoxins in rice, corn and flour samples.The recoveries of the extraction process ranged from73.12%to104.41%with relative standard deviation ranging form5.93%-12.99%in all samples, when samples were fortified at three different concentrations levels (20μg kg-1、80μg kg-1and150μg kg-1). The developed method suggests that it is suitable for the accurate quantification of4aflatoxins at trace levels in grain samples.