- Publication date
- 17 April 2015
Proficiency Test on the determination of 4 EU marker PAHs in milk chocolate and low fat cocoa powder
The European Union Reference Laboratory for Polycyclic Aromatic Hydrocarbons organises a proficiency test on the determination of 4 EU marker PAHs in cocoa products.
The objective of this study is to evaluate the capabilities of EU food control laboratories in the determination of 4 EU marker PAHs in chocolate and low fat cocoa powder.
Only national reference laboratories (NRLs) for PAHs and EU official food control laboratories (OCLs) can participate in the study.
Participation is free of charge for NRLs for PAHs. The participation fee for other official food control laboratories, which do not have national reference laboratory status, is EUR 350 (three hundred fifty) per registration! Participation fees are due with the delivery of the test samples.
Test material and analytes
The test materials are commercial chocolate and cocoa powder samples containing the target analytes (see Table 1). Samples will be sent to the participants in May. In addition participants will get an ampoule with a solution of the target PAHs with disclosed analyte content, in, depending on their preference, either acetonitrile or toluene, which will allow the participants verifying instrument calibration against an independent standard. Results do not have to be reported for the standard solution.
The measurands are the 4 EU marker PAHs as listed in Table 1.
Results have to be reported for the contents of the individual analytes as well as for the sum of the four PAHs. Additionally the analyte contents have to expressed both on product and on fat basis.
Table 1: measurands
Participants are requested to perform three independent analyses of each sample using a method of their choice. The analyses shall be performed on the same day. Participants have to report the results for individual analytes of the replicate analyses. All results have to be reported corrected for recovery, and have to be accompanied by the respective measurement uncertainty.
The performance of the participants in the determination of PAHs in the two test samples will be rated by z-scores and zeta-scores.
The standard deviations for proficiency assessment will be derived:
- for all four analytes from the fitness-for-purpose function given in Commission Regulation (EU) No 836/2011 assuming a value of 0.3 µg/kg for the limit of detection.
- for the sum parameter by propagating the individual standard deviations for proficiency assessment of the four analytes applying the law of error propagation.
Via invitation by e-mail and submitting a filled in registration form.
|Reporting of results:||4 weeks after dispatch|
|Reporting to participants:||September 2015|
|Sample dispatch:||End of May 2015|