The purpose of this proficiency test was to investigate the current measurement capacities of testing laboratories for pyrrolizidine alkaloids in honey and plant materials. The scheme consisted of two parts: Benchmarking performance of laboratories against known estimates of pyrrolizidine alkaloids in the samples and checking for methodological differences while measuring naturally contaminated materials.
Twenty-eight laboratories expressed their will to participate and analysed multiple analytes in several test samples of honey and plant material.
The analysis of spiked honey showed no statistical differences between determining a common sum parameter for alkaloids and individual determination. A significant difference has been found however for of naturally contaminated materials. Individual alkaloid determination showed significantly lower results, possibly because of the presence of substances contributing to the sum parameter that were not in the scopes of the methods applied as well as lack of standard materials available on the market.
Satisfactory performance for all of analytes has been achieved by more than half of participants analysing for both: sum parameter, and alkaloids analysed individually.JRC.D.5-Standards for Food Bioscienc
