Report on the 6th Inter-Laboratory Comparison Test Organised by the European Union Reference Laboratory for Polycyclic Aromatic Hydrocarbons

摘要

The European Union Reference Laboratory for PAHs (EU-RL-PAHs), operated by the Institute for Reference Materials and Methods (IRMM) of the Joint Research Centre (JRC), organises yearly one or more proficiency tests (PTs) within the scope of the Regulation (EC) 882/2004.The proficiency test here reported concerned the determination of the 15+1 EU priority polycyclic aromatic hydrocarbons (PAHs) in an infant formula test sample. Participants to these PT were National Reference Laboratories for PAHs (NRLs-PAHs). The number of participants was 25. They were requested to report for the future four target PAHs (benz[a]anthracene, benzo[b]fluoranthene, benzo[a]pyrene, and chrysene) quantitative results, and absence or presence of the other 12 PAHs.The PT was organised along the lines of the IUPAC Harmonised Protocol for the Proficiency Testing of Analytical Chemistry Laboratories.The test material used was dry infant formula spiked with a 15 + 1 EU priority PAHs and a solution of the target analytes in, depending of the preference of the particular laboratory, either acetonitrile or toluene.The results for the four target PAHs were rated with z-scores and zeta-scores. About 88 % of the reported results were attributed with z-scores with an absolute value of below two, which is the threshold for satisfactory performance. The proportion of satisfactory zeta-scores was smaller, which was caused by potentially too optimistic measurement uncertainty estimates.