HBM4EU ICI EQUAS report PAHs in urine round 1

Within the framework of the HBM4EU project, an Inter-Laboratory Comparison Investigation (ICI) was organized and conducted for the analysis of PAH metabolites (PAH met. correspond to 13 biomarkers: 1-hydroxynaphthalene (1-naphthol), 2-hydroxynaphthalene (2-naphthol), 1,2-dihydroxynaphthalene (1.2-DHN), 2-hydroxyfluorene (2-FLUO), 3-hydroxyfluorene (3-FLUO), 9-hydroxyfluorene (9-FLUO), 1-hydroxyphenanthrene (1-PHEN), 2-hydroxyphenanthrene (2-PHEN), 3-hydroxyphenanthrene (3-PHEN), 4-hydroxyphenanthrene (4-PHEN), 9-hydroxyphenanthrene (9-PHEN), 1-hydroxypyrene (1-PYR), 3-hydroxybenzo(a)pyrene (3-BaP)) in urine. The study was performed from May 2018 to June 2018. Nine different test samples consisting of 5 mL urine each (6 of them spiked with the biomarker (PAH met. low and PAH met. high), three of them containing native control material (PAH met. native) were prepared and sent to the participating laboratories for analysis. Homogeneity assessment of the control materials confirmed that the materials were adequately homogeneous. The stability test demonstrated no significant loss of the biomarkers during the course of the ICI. Laboratory results were rated using z-scores in accordance with ISO 13528 and ISO 17043. The standard deviation for proficiency assessment (also called target standard deviation) was set to FFP = 25%, as described in 5.3. In total, 19 laboratories from 11 countries participated in the ICI. The participation in the ICI was satisfactory; 17 out of 19 laboratories submitted their results. Biomarkers 1.2-DHN, 3-FLUO, 9-FLUO, 9-PHEN and 3-BaP could not be evaluated because the number of participating laboratories is smaller than seven.