Abstract:
Pyrrolizidine alkaloids (PAs) are important plant toxins causing poisoning in livestock, leading to
significant financial and production losses each year. It may also enter the human food chain as
contaminants of grains, via animal products such as milk, eggs and honey or herbal remedies. Not all PAs
are toxic and it is important to be able to distinguish between toxic and non-toxic PAs. We developed a
sensitive and selective analytical method to determine toxic 1,2-unsaturated PAs concentrations in plant
extracts by liquid chromatography–mass spectrometry (LC–MS) with electrospray ionization and
precursor ion experiments. Multi-reaction-mode experiments were used to quantify the concentrations
of the different unsaturated PAs and results were expressed as mg/g retrorsine equivalents. The results
obtained on Crotalaria sphaerocarpa contaminating maize crops have important implications.
