Because of the mutagenic and carcinogenic properties of some of the polycyclic aromatic hydrocarbons (PAHs) they are monitored regularly in environmental matrices including foodstuffs.Establishment of levels and implemention of regulations to control PAH-food contamination requires reliable identification and quantification of these compounds. This difficult task of analysis of trace amount of individual PAHs (ug/kg) in such complex matrices would be greatly facilitated by the availability of food matrix reference materials with certified PAH level. At present there are no such food reference materials. Therefore the Community Bureau of Reference Materials (BCR) of the European Commission has initiated a programme to develope such a material. BCR has organized three preliminary intercomparison studies with food materials. Basing on the promising results achieved in the feasibility studies 500 units of 50 mL sample of one blank coconut oil and one spiked coconut oil (with low ppb level of selected PAHs) were prepared and the homogeneity- and the stability studies of the materials were done by RIVM , Bilthoven (NL).
The objective of this project is to certify the content of the selected PAHs of the blank coconut oil and the spiked coconut oil candidates reference materials by means of an
The long term stability study of the materials done by the coordinatorfor -20 °C and 25 °C showed no significant instability.The certification interlabotory exercise was carried out with 13 laboratories from 6 EU countries, usung a variety of extraction and cleanup procedures and different methods of analysis.The certification report is now published (EUR Report no. 17545 EN).The two coconut oil reference materials (CRM458 & 459) with the certified mass fractions of pyrene, chrysene, benzo[k]-fluoranthene, benzo[a]pyrene, benzo[ghi]perylene and indeno[1,2,3-cd]pyrene are available by now.
The coordinator has to check the long term stability of the materials. For the calibration and recovery purposes the coordinator provides the participating laboratories with the concentrated PAH standard solutions, which were prepared form solid PAH-CRMs and were counterchecked by at least three laboratories.The a tasks of the laboratories are a) 6 independent analyses of the blank coconut oil
b) 6 independent analyses of the spiked coconut oil
c) 3 determinations of recovery rates
d) additional measurements for the determination of detection limit and background