Analysis of four polycyclic aromatic hydrocarbons in plant-based food supplements—results of a collaborative study

The determination of carcinogenic polycyclic aromatic hydrocarbons (PAHs) in food supplements is challenging, especially due to the presence of other e.g. heterogeneous PAH-like compounds in the matrix. A collaborative study with 12 participants was conducted in order to assess performance characteristics of a fast method intended to analyse the four regulated PAHs (PAH 4) benzo[<i>b</i>]fluoranthene [BbF], benz[<i>a</i>]anthracene [BaA], chrysene [CHR] and benzo[<i>a</i>]pyrene [BaP] in five different plant-based food supplements in the form of capsules, powder, and tablets. The principle of the method includes the extraction of PAHs with ethyl acetate: cyclohexane followed by a two-step SPE cleanup and final analysis by GC-MS or LC-FLD. The regulated maximum level for BaP is 10 µg/kg and, for the PAH 4, 50 µg/kg. Accordingly, the method was validated for the regulated PAH 4 analytically challenging concentration range from 2.5 µg/kg to 6.9 µg/kg. The performance criteria for the method set in European Regulation No 333/2007 for the overall repeatability, reproducibility (HorRat values below 2), and recovery (range 50–120%) were fulfilled. Based on the statistical evaluation of the results, it was concluded that the method is a suitable alternative to existing methods and should be studied for additional matrices.