High through-put aflatoxin determination in plant material by automated solid-phase extraction on-line coupled to laser-induced fluorescence screening and determination by liquid chromatography-triple quadrupole mass spectrometry

A screening test based on laser-induced fluorescence (LIF) and a method for individual identification - quantitation of aflatoxins (AFs) in olive leaves and drupes, based on chromatographic separation and triple-quad mass-spectrometry detection with electrospray ionization in positive mode, is here reported. The sensitivity and selectivity of both methods are enhanced by a preconcentration-cleanup step developed by a Prospekt station. The analysis frequency is at least 3.5 samples/h. The screening test makes able to detect the target analytes at concentrations of 0.7 mu g/kg without "false negatives". The LC-MS/MS method provides limits of detection (LOD) and quantification (LOQ) ranging between 0.01-0.03 and 0.03-0.11 mu g/kg, respectively. The linear dynamic range is between LOQ-50 mu g/kg. The between-day precision, expressed as relative standard deviation, ranges between 0.97-2.86% and the within laboratory reproducibility, also expressed as RSD, between 1.63% and 4.84%. (C) 2008 Elsevier BY. All rights reserved.