EURL PT 1060

Proficiency Test on the determination of 4 marker PAHs in mussels

The European Union Reference Laboratory for Polycyclic Aromatic Hydrocarbons organises a proficiency test on the determination of 4 marker PAHs (see Table 1) in bivalve molluscs.

The objective of this study is to evaluate the capabilities of European National Reference Laboratories (NRLs) and Official Food Control Laboratories (OCLs) in the determination of the target analytes and their sum in bivalve molluscs and to perform compliance assessment according to the corresponding legislative limits.

Only NRLs for PAHs and OCLs as indicated by NRLs can participate in the study.

Participation is admitted to maximum 50 official food control laboratories, which will be accepted in the order of registration.

Participation is free of charge for NRLs for PAHs.

The participation fee is EUR 300 (three hundred) per registration for OCLs, which do not have NRL status

Test material and analytes

The set of test samples will consist of:

1. an amber glass vial containing about 15 g of lyophilized mussels sample, and
2. an amber glass vial containing about 30 g of frozen mussels,

for the determination of the EU marker PAHs (see Table 1).

In addition, participants will get an ampoule with a solution of PAHs with disclosed analyte content, in, depending on their preference, either acetonitrile or toluene. This solution will be supplied to allow the participants verifying their instrument calibration against an independent standard.

Table 1: The target analytes of the comparison:

General outline

Participants are requested to perform three independent analyses of the edible oil. These analyses shall be performed on the same day. Participants have to report the results for individual analytes of the replicate analyses. These results have to be reported corrected for recovery.

Participants will be also asked to report a single value for scoring, the "final value", both for the individual analytes as well as for the sum of the four marker PAHs. These results will have to be reported corrected for recovery and have to be accompanied by the respective measurement uncertainty.

At the end participants will be ask to perform compliance assessment according to the corresponding legislative limits.

Further details will be communicated to participants at a later stage.

Performance assessment:

The performance of the participants in the determination of PAHs in bivalve molluscs will be rated by z-scores and zeta-scores.

The standard deviations for proficiency assessment will be derived:

1. For the four individual target analytes, from the fitness-for-purpose function given in Commission Regulation (EC) No 333/2007, assuming a value of 0.3 µg/kg for the limit of detection.
2. For their sum, from the P - values of the individual analytes, applying the law of uncertainty propagation