Results of an European inter-laboratory comparison study on the determination of the 15 + 1 EU priority polycyclic aromatic hydrocarbons (PAHs) in liquid smoke condensates

A collaborative study on the determination of the 15 + 1 EU priority PAHs in Primary Smoke Condensate (PSC) investigating the performance profile of EU Member States’ laboratories and supporting the work carried out by the European Food Safety Authority on smoke flavourings was organised. Two spiked liquid smoke condensate materials were employed in this study. The results of 25 laboratories from across the European Union, using either high performance liquid chromatography with fluorescence detection or gas chromatography with mass selective detection, were evaluated by application of robust statistics. The assessment of the data indicated broadened Gaussian distributions for all analytes. For benzo[a]pyrene (BaP), benzo[a]anthracene (BaA), chrysene and 5-methylchrysene more than 80% of the respective reported values gave rise to a satisfactory score of |z| ⩽ 2. For benzo[b]fluoranthene, benzo[k]fluoranthene, and dibenzo[a,l]pyrene 70–80%, for the remaining analytes less than 70%, and for dibenzo[a,i]pyrene 52% of the scores were satisfactory. No systematic differences could be detected between values reported by laboratories using methods based on HPLC and the values related to methods based on GC for most of the analytes, except for benzo[k]fluoranthene and benzo[c]fluorene. In both cases laboratories using GC based methods reported about 50% higher values than laboratories using HPLC based methods. The overview on all z-scores sorted by laboratory revealed broad distributions and/or laboratory biases for several laboratories. An assessment of the reported method performance parameters revealed that for the two regulated compounds, BaP and BaA, only two thirds of the reported data were in compliance with Regulation (EC) 627/2006. Overall the methods used in the participating laboratories were – with ample room for improvement – well on the way to comply with European legislation.