A rapid, high-throughput method employing ultra-performance liquid chromatography with tandem quadrupole mass spectrometry (UPLC-MS/MS) was developed and optimized for simultaneous quantification and confirmation of 64 pesticide residues and their toxic metabolites in fruit extracts prepared by a buffered QuEChERS procedure. The total time required for UPLC-MS/MS analysis was 8 min plus 2 min for re-equilibration to the initial UPLC conditions. Performance characteristics were determined for apple extracts spiked at 10 microg kg(-1). The repeatability of measurements expressed as relative standard deviations was in the range 1.5-13% at this level for most analytes. Thanks to very low limits of quantification (<10 microg kg(-1)for the majority of pesticides), an optimized method allows for the reliable control of not only common maximum residue limits (MRLs) set by European Union regulation for various pesticides/fruit combinations, but also of a uniform MRL of 10 microg kg(-1)endorsed for baby food.

Department of Food Chemistry and Analysis Institute of Chemical Technology Technicka 3 CZ 166 28 Prague 6 Czech Republic