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

Abstract

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[b]fluoranthene [BbF], benz[a]anthracene [BaA], chrysene [CHR] and benzo[a]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.

Keywords:

• PAH
• food supplements
• SPE
• collaborative trial
• GC-MS
• LC-FLD

Acknowledgements

The authors would like to thank laboratory technician Riuyinosa Igbinovia for laboratory assistance on homogeneity tests, consultant Mikael Pedersen for availability on questions regarding statistic data handling, and Professor Jens Jørgen Sloth for inspiration to ring-trial setup and reporting. All participating laboratories are thanked for their voluntary participation in the collaborative trial and comments to the method.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

Parts of this work were included in the European Reference Laboratory for Processing Contaminants [EURL-PC, SI2.802033].