A fast and simple LC-ESI-MS/MS method for detecting pyrrolizidine alkaloids in honey with full validation and measurement uncertainty

A fast and simple method was developed to determine pyrrolizidine alkaloids (PAs) in honey using liquid chromatography tandem mass spectrometry (LC- MS/MS) with electrospray ionization (ESI). An efficient extraction procedure was carried out by simply diluting with water, without the need of any additional clean-up steps. A full validation of the method was performed according to Commission Decision 2002/657/EC. The method was linear in the 050 pg kg(-1) range and presented satisfactory intra-day and inter day precision with relative standard deviations of 1.45-10.2% and 1.60-1-0.2%, respectively. The measurement uncertainty, limit of detection (LOD) (0.1-1.0 mu g kg(-1)) and limit of quantification (LOQ) (0.2-1.5 mu g kg(-1)) were also calculated. The proposed method was applied to analyse eight PAs, namely, senecionine, senecionine-N-oxide, echimidine, intermedine, lycopsamine, retrorsine, monocrotaline and retrorsine-N-oxide, in 92 commercial honey samples from Brazil. At least three PAs were detected in 99.1% of the samples. PM were not detectable (