OPTIMIZATION OF EXTRACTION METHOD FOR AFLATOXINS AND OCHRATOXIN A DETERMINATION IN GRAIN-BASED PRODUCTS Xu, Jianwen A method for simultaneous detection of mycotoxins using high performance liquid chromatography (HPLC) coupled with a fluorescence detector (FLD) and photochemical reaction for enhanced detection (PHRED) for post-column derivatization was developed in this study. Mycotoxins of interest included aflatoxin B1, B2, G1, G2 and ochratoxin A. Samples extraction was performed with 80% acetonitrile aqueous solution. Mycosep® 226 Aflazon+ columns were employed for samples cleanup. This optimized method achieved low limit of detection (LOD) that ranged from 0.1ng/g to 0.5ng/g and a limit of quantification (LOQ) ranged from 0.5ng/g to 2.5ng/g for all five mycotoxins in all cereal matrices (wheat, barley, oats) studied, which was under the regulatory limit (20ng/g) from United States. Mean recovery rates for all five mycotoxins from all spiked samples ranged from 93.88% to 104.40%, with high repeatability (relative standard deviation ranged from 1.38% to 8.79%). This method was used to determined ochratoxin A in cereal samples purchased from grocery stores in the United States. M.S. in Food Safety and Technology, July 2012 Cappozzo, Jack 2012-07-16 2012-07 Thesis application/pdf islandora:7468 http://hdl.handle.net/10560/2919 ChBE / Chemical and Biological Engineering Illinois Institute of Technology en In Copyright http://rightsstatements.org/page/InC/1.0/ Restricted Access