Report on the 5th inter-laboratory comparison test organised by the European Union Reference Laboratory for Polycyclic Aromatic Hydrocarbons : 15 + 1 EU priority PAHs in edible oil and acetonitrile

The Community Reference Laboratory for PAHs (CRL-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 oil test sample. Participants to these PT were National Reference Laboratories for PAHs (NRLs-PAHs) and an expert laboratory, which was covered by the Technical Assistance and Information Exchange (TAIEX) programme for Balkan Countries. The number of participants was 27. 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 olive oil spiked with a 15 + 1 EU priority PAHs and a solution of the target analytes in acetonitrile. The results from participants were rated with z-scores. About 81 % of the reported results were attributed with z-scores with an absolute value of below two, which is the threshold for satisfactory performance.