Fig. 3

Selected examples for the results of the validation trials. Selected substance/matrix combination: a fluoranthene/COPAH, b benzo[a]pyrene/SLPAH, c sum PCB/RSPCB and d PCB 180/SOPCB. Individual results of laboratories (L01–L34) for the analysis of substances are displayed with increasing concentration along the x-axis. The analytical methods used are illustrated by white bars for HPLC or GC-ECD and grey bars for GC-MS. Outliers are highlighted by red frames. The error bars represent the within-lab standard deviation. Different extraction techniques and solvents are indicated by numbers: 1 agitation mixture polar/non-polar, 2 agitation non-polar, 3 pressurised liquid extraction non-polar, 5 soxhlet non-polar, 7 ultrasonic bath polar, 8 agitation + ultrasonic bath non-polar