Last Updated: 19-10-2020 15:46
Within the framework of the HBM4EU project, an interlaboratory comparison was organised for the determination of a biomarker for the mycotoxin deoxynivalenol (DON) in urine.
The study was performed in February/March 2020 and was conducted to assess the comparability and reliability of analytical methods across the participating expert laboratories.
The HBM4EU QAU had selected six expert laboratories for mycotoxin biomarkers in urine. The expert laboratories were from six different countries in Europe.
Each participant received two control materials of human urine to be analysed for total DON (total of free and conjugated). The laboratories were requested to perform a single analysis and to submit the results to the organiser within 3 weeks. Due to COVID-19 one laboratory could not analyse the sample before the deadline. An extension of the deadline was granted but after reopening of this laboratory in May, it decided to withdraw from the ICI. Hence, results were obtained from five laboratories.
A first assessment of comparability of results was done by calculation of the mean, the RSD, and the relative uncertainty of the mean. Results were compared against the mean through a Z-score when the relative uncertainty of the mean was within 17.5%. In this study, the uncertainty of the mean of the five laboratories exceeded this value meaning that the overall results were not comparable. It was noticed that, as in the first round, the lowest concentrations were obtained when using β-glucuronidase(/sulfatase) from Helix Pomatia. Therefore also in this round the consensus values were based on the results from laboratories using β-glucuronidase from E. coli.
All five laboratories reported quantitative results. Results were comparable for four laboratories.
Recommendations were made to improve comparability of results in the next round.