Determination of PAHs in Paprika Powder Using a Novel SPE Cartridge and dedicated GC Stationary Phase

Klaus Buckendahl, Merck/Sigma-Aldrich Chemie GmbH, Taufkirchen, Germany (klaus.buckendahl@merckgroup.com)
Katherine Stenerson, Milliporesigma, Bellefonte Pa, Usa
Jennifer Claus, Milliporesigma, Bellefonte Pa, Usa

Contamination of paprika powder with polynuclear aromatic hydrocarbons (PAHs) can occur when pepper plants are exposed to these pollutants in the environment and/or during the drying process. The European Union (EU) has regulated the maximum allowable levels of several PAHs in dried herbs and spices. Specifically for paprika, the maximum allowable levels have been set to 10 ng/g for benzo[a]pyrene and 50 ng/g total for the sum of benzo[a]pyrene, chrysene, benzo[a]anthracene and benzo[b]fluoranthene [1].

The classical cleanup methods used include gel permeation chromatography (GPC), and solid phase extraction (SPE) with silica gel. In recent times, a new approach for cleanup of high background samples to be analyzed for PAHs has utilized a dual layer SPE cartridge containing a Florisil^® top layer and zirconia coated silica (Z-Sep)/C18 bottom layer. This cartridge has been used for isolation of PAHs from edible oils and for cleanup of extracts of biota samples [2,3].

In this work, PAHs were analyzed from paprika powder using an optimized QuEChERS extraction, followed by cleanup with the dual layer cartridge. Compared to QuEChERS cleanup with loose sorbents, the dual layer SPE cartridge approach yielded a significantly cleaner extract, especially for C16 and C18 fatty acids. The final extraction and cleanup procedures resulted in recoveries of >70% at a spiking level of 10 ng/g; calculated without internal standard correction. Analysis of the PAHs was performed on a new developed GC column dedicated for PAHs to chromatographically resolve isomeric sets which cannot be discerned based on MRMs.

 

References

1. Commission Regulation (EU) 2015/1933. Off. J. Eur. Union 2015, L282/11.

2. Cabillic, J.; Fallot, C., AQUAREF Report 2015 - 22 p.

3. Anderson, K.A.; Szelewski, M.J.; Wilson, G; Quimby, B.D.; Hoffman, P.D.,  J. Chrom. A. 2015, 1419, 89-98.