AbstractThe pyrrolizidine alkaloids of 68 Australian honey samples as well as extracts of Australian and New Zealand pollen samples collected from anthers, and pollen baskets harvested from honeybees, were identified and quantified using HPLC-atmospheric pressure chemical ionization (APCI)-MS. HPLC-electrospray ionization (ESI)-MS was applied for simultaneous quantitation of the alkaloids and their N-oxides. The highest level of pyrrolizidine alkaloid content, in excess of 2500 µg equivalents of echimidine per kg of honey (ppb), was observed with an Echium plantagineum-derived sample. Honeys attributed to E. plantagineum, Heliotropium europaeum and H. amplexicaule were determined by the presence of echimidine, heliotrine and indicine respectively as the major alkaloid observed, as identified by HPLC-APCI-MS. Use of the silica-based SCX SPE columns on the honey and pollen samples tentatively identified a new suite of alkaloids/N-oxides characteristic of E. vulgare. The highest level determined was approximately 5000 ppb. Four samples returned levels of between 1200 and 2850 ppb and four were between 550 and 950 ppb. The level of pyrrolizidine alkaloids/N-oxides in the pure pollen was considerably higher compared to the honey at about 11 000 ± 3000 ppm (mg/kg) whereas levels in the pollen baskets from honeybees returned lower levels of alkaloids, with a range of 925 to 4000 ppm and a mean (from 4 samples) of 2125 ppm. The combination of silica-based SCX SPE and HPLC-ESI-MS analysis has confirmed the natural predominance of N-oxides over the parent, tertiary-base pyrrolizidine alkaloids in the honey and pollen samples.