DETERMINATION OF PYRROLIZIDINE ALKALOIDS IN HONEY FROM SELECTED SITESBY SOLID-PHASE EXTRACTION AND HPLC-MS

A method was developed for the determination in honey of the Ragwort ( Senecio jacobaea) derived pyrrolizidine alkaloids jacoline, jacozine, jacobine, seneciphyline and senecionine, combining solid-phase extract ion with high performance liquid chromatography and atmospheric pressu re chemical ionization mass spectrometric detection. The method allowe d determination of individual alkaloids and offered a considerable imp rovement in terms of speed, sensitivity and specificity over previous approaches, but was not suitable for determination of jaconine, a mino r alkaloid in Ragwort. Instrument calibrations were linear over the ra nge 0.005 to 10.0 mu g/ml, equivalent to approximately 0.001 to 2.0 mg /kg in honey with the extraction method used and allowing for observed recoveries. Detection limits in honey were 0.002 mg/kg. Recoveries fo r most of the alkaloids were between 57 and 70%. The alkaloids have be en determined in a number of samples of honey selected after pollen id entification and counting. The alkaloids were not detectable in sample s containing two grains or less of Ragwort pollen per gram of honey. S amples collected in late July and August contained Ragwort pollen at 1 5-21 grains/g and total alkaloid concentrations of 0.011-0.056 mg/kg. Similar contributions to the total were made by jacozine, seneciophyll ine and senecionine, with jacobine making a larger and jacoline a smal ler contribution. Two samples of honey containing Ragwort pollen at 24 and 16 grains/g had total alkaloid concentrations of 0.42 and 1.48 mg /kg respectively (not corrected for recovery). The alkaloid profile in these samples was dominated by seneciphylline and senecionine which t ogether comprised 90-95% of the total. Alkaloids were not detected in retail honeys.