A reversed phase high performance liquid chromatography method for the determination of fumonisins B1 and B2 in food and feed using monolithic column and positive confirmation by liquid chromatography/tandem mass spectrometry

The development of a reversed phase high performance liquid chromatography fluorescence method for the determination of the mycotoxins fumonisin B-1 and fumonisin B-2 by using silica-based monolithic column is described The samples were first extracted using acetonitrile water (50 50 v/v) and purified by using a C-18 solid phase extraction-based clean-up column Then pre-column derivatization for the analyte using ortho-phthaldialdehyde in the presence of 2-mercaptoethanol was carried out The developed method involved optimization of mobile phase composition using methanol and phosphate buffer injection volume temperature and flow rate The liquid chromatographic separation was performed using a reversed phase Chromolith (R) RP-18e column (100 mm x 4 6 mm) at 30 degrees C and eluted with a mobile phase of a mixture of methanol and phosphate buffer pH 335 (78 22 v/v) at a flow rate of 1 0 mL min(-1) The fumonisins separation was achieved in about 4 min compared to approximately 20 min by using a C-18 particle-packed column The fluorescence excitation and emission were at 335 nm and 440 nm respectively The limits of detections were 0 01-0 04 mu g g(-1) fumonisin B-1 and fumomsin B-2 respectively Good recoveries were found for spiked samples (0 1 05 1 5 mu g g(-1) fumonisins B-1 and B-2) ranging from 840 to 106 0% for fumonisin B-1 and from 81 0 to 103 0% for fumonisin B-2 Fifty-three samples were analyzed including 39 food and feeds and 14 inoculated corn and rice Results show that 12 8% of the food and feed samples were contaminated with fumonism B-1 (range 0 01-0 5 mu g g(-1)) and fumonisin B-2 (0 05 mu g g(-1)) The total fumonisins in these samples however do not exceed the legal limits established by the European Union of 0 8 mu g g(-1) Of the 14 Inoculated samples 57 1% contained fumonisin B-1 (0 16-41 0 mu g g(-1)) and fumonisin B-2 (range 0 22-50 0 mu g g(-1)) Positive confirmation of selected samples was carried out using liquid chromatography-tandem mass spectrometry using triple quadrupole analyzer and operated in the multiple reaction monitoring mode (C) 2010 Elsevier B V All rights reserved