Report on the inter-laboratory comparison organised by the European Union Reference Laboratory for Polycyclic Aromatic Hydrocarbons : four marker PAHs in smoked black pepper

This report presents the results of the inter-laboratory comparison (ILC) organised as a proficiency test (PT) by the European Union Reference Laboratory for Polycyclic Aromatic Hydrocarbons (EURL PAHs) on the determination of the four EU marker PAHs, benz[a]anthracene (BAA), benzo[a]pyrene (BAP), benzo[b]fluoranthene (BBF) and chrysene (CHR) in smoked black pepper . The test material used in this exercise was commercial smoked black peppercorns acquired from an on-line store, which were in the EURL PAH laboratories finely ground and homogenised. Participants also received a solution of PAHs in the solvent of their choice (either toluene or acetonitrile) with known PAH content for the verification of their instrument calibration. Both officially nominated National Reference Laboratories (NRLs) and official food control laboratories (OCLs) of the EU Member States participated in the study. Twenty-nine NRLs and 18 OCLs subscribed for participation. The test material was characterised at the EURL PAH. The assigned values and their uncertainties were determined from independent replicate measurements on two different days by a primary method of measurement. Participants were free to choose the method of analysis. The performance of the participating laboratories in the determination of the target PAHs in the test material was expressed by both z-scores and zeta-scores. Additionally, the compliance of reported method performance characteristics was checked against specifications given in legislation. This PT demonstrated the competence of the participating laboratories in the analysis of regulated PAHs in smoked black pepper. About 67% percent of the reported test results were graded with z-scores below an absolute value of two, indicating acceptable agreement with the independently assigned values of the test material. The EURL PAH asked participants to assess also compliance of the sample with legislative limits. Seventy one percent of the participants, who answered to this question, assessed the compliance of the test sample with EU legislation correctly. The EURL-PAH is operated by a JRC Unit, which is an ISO/IEC 17043 accredited PT provider and the respective rules were applied during all phases of this PT.