Proficiency test results for PAH analysis are not method-dependent

Two independent proficiency testing schemes for PAH analysis conducted an assessment of possible method dependency in the results. One scheme was from a commercial provider (FAPAS), and the other one run under the auspices of the European Union Reference Laboratory for PAHs. Both schemes analysed several of their datasets for the four EU marker PAHs benzo[a]pyrene, benz[a]anthracene, benzo[b]fluoranthene and chrysene. Method details supplied by the participants enabled the test results to be separated according to whether gas chromatographic or liquid chromatographic approaches had been used. Participant laboratories can be differentiated by this broad categorisation. The data from both schemes demonstrated that there was no significant difference found in results between laboratories applying either method. Occasional differences in results can be attributed either to the non-symmetrical distribution of data or the absence of general good analytical practice. Laboratories setting up to do PAH analysis need not procure alternative instrumentation if their existing facilities could be applied.