modular method for the determination of polycyclic aromatic hydrocarbons in spices and dried herbs by gas chromatography–tandem mass spectrometry

This paper describes a method for quantification of the four regulated polycyclic aromatic hydrocarbons (pahs), (benzo[a]anthracene [baa], chrysene [chr], benzo[b]fluoranthene [bbf] and benzo[a]pyrene [bap]), in the wide matrix group of spices and dried herbs by gas chromatography–tandem mass spectrometry (gc–ms/ms). the design of this method was drawn up using basic material and equipment available in most laboratories and a modular clean-up fitting for each category of this very diverse matrix group. the clean-up strategy consists of dividing this matrix group into three subclasses: regular spices, highly pigmented matrices and complex mix of spices/fatty spices. depending on the subclass, spe sorbent is adapted to remove maximum of co-extracts and to obtain clean samples. this method has a limit of quantification of 0.5 μg kg−1 for each pah and the validation criteria fully satisfied the commission regulation (eu) no. 836/2011 (< 0.9 μg kg−1). the quantification performed by isotopic dilution allowed the complete correction of matrix effect and led to very good validation data with a mean recovery close to 100% and a within-laboratory reproducibility below 10% (≤ 22% in regulation (eu) no. 836/2011) for each pah and for each matrix group at all concentration levels tested. furthermore, the method’s performance characteristics have been successfully assessed using a representative certified reference material for each subclass and at a level close to the mrl: 10 μg kg−1 for bap and 50 μg kg−1 for the sum of the 4 pahs.