Pressurized liquid extraction followed by liquid chromatography-mass spectrometry for determination of zearalenone in cereal flours

A method for determination of zearalenone in cereal flour has been developed applying pressurized liquid extraction (PLE) using methanol/acetonitrile (50:50 v/v) as the extraction solvent. The extracted samples were analyzed with liquid chromatography coupled to mass spectrometry (LC-MS) with an electro spray ionisation interface (ESI). The method was validated as a quantitative confirmatory method according to the Eu Commission Decision 2002/657/EC. Recoveries of the extraction step data were satisfactory with values higher then 70%. Quantification limits (LOQ) were 5 mu g/kg for ESI (+) and 1 mu g/kg for ESI (-). Twenty one flour samples produced in different countries were extracted and analyzed by LC-MS (ESI) negative ionisation followed by LC-M5 (ESI) positive ionisation for confirmative purposes, quantification was based on matrix-matched standard curves to compensate disturbing matrix effect. Only one sample was confirmed containing zearalenone below levels regulated by European Commission. (C) 2009 Elsevier Ltd. All rights reserved.