The QUASIMEME Laboratory Performance Study of polycyclic aromatic hydrocarbons (PAH): Assessment of the first three rounds, 1994–1995

A Laboratory Performance Study (LPS) has been undertaken to improve the measurement of polycyclic aromatic hydrocarbons (PAH) in marine sediments as part of the QUASIMEME project. The first three rounds of the exercise included the analysis of standard solutions, and both raw and cleaned-up sediment extracts, and were intended to test calibration, chromatographic performance and clean-up techniques. The methods used were based on both gas chromatography (GC) and high-performance liquid chromatography (HPLC). The number of participating laboratories was 25 in Rounds 1 and 2, and 16 in Round 3. For the 10 PAH determined, robust coefficients of variation for the analysis of standard solutions varied from 8–30%, 13–22%, and 8.8–21% in the three rounds of the exercise to date. For a raw sediment extract the robust coefficients of variation varied from 17–34%. The two major factors limiting performance were calibration procedures, which seemed to apply across the range of PAH determined, and the need to avoid errors when calculating results. Good results can be obtained using both GC and HPLC techniques when methods are selected and applied properly, with appropriate care and control.