With regard to the ergot alkaloids, it can be observed that the earlier eluted peaks such ergometrine and ergometrinine show higher signal suppression, whereas the decrease in signal is less pronounced for the late eluted peaks. Comparing these data to those reported by Krska et al. (2008), the latter revealed less matrix effects. This is most probably due to differences in the LC–MS equipment used. Indeed, a significant difference in matrix effects was observed when the method described here was transferred to another instrument (data not shown).