UHPLC-ToF-MS method for determination of multi-mycotoxins in maize: Development and validation

An Ultra-High Performance Liquid Chromatography combined with Time-of-Flight Mass Spectrometry (UHPLC-ToF-MS) method has been developed for determination of nine mycotoxins, namely aflatoxins (AFB(1), AFB(2), AFG(1) and AFG(2)), ochratoxin A (OTA), zearalenone (ZEA), toxin T2 (T2) and fumonisins (FB1 and FB2) in maize. The method included a two-step extraction with acetonitrile 80% (v/v). After optimization, the analytical method was validated. The different concentrations tested take in account the Maximum Levels (ML) for maize (Commission Regulation EC no. 1881/2006) and good results for repeatability (%RSDr <= 15.4%), reproducibility (%RSDR <= 15.9%) and recovery (77.8-110.4%, except for AFG2 at 2 mu g/kg which presented a recovery of 73.4%) were achieved. These met the performance criteria imposed by Commission Regulation (EC) no. 401/2006. The method was applied to twenty-two samples from Portuguese producers of maize. Fumonisins were the most frequently detected mycotoxins, but the levels do not exceed those imposed by European legislation.