Comparison between two different approaches in the uncertainty estimation for the chromatographic analysis of aflatoxin M₁: from single laboratory validation data and from proficiency test results

The analytical method to determine aflatoxin M-1 in milk by HPLC with immunoaffinity column clean-up and fluorescence detection has been validated by using certified reference materials and spiked samples. These validation data have been analysed to obtain the uncertainty estimation following the bottom-up approach as reported by Eurachem. The results obtained with this method have been compared with the expanded uncertainty calculated from data obtained during the years 2002-2007 by participation in Fapas proficiency testing.