Metrological traceability for benzo[a]pyrene quantification in airborne particulate matter

Airborne particulate matter (PM) represents one of the most important sources of urban pollution due to its physical and chemical properties. There is a great concern for PM dangerous effects on human health because particles can deeply penetrate into the respiratory system, carrying the contaminants adsorbed onto their surface. Polycyclic aromatic hydrocarbons (PAHs) are a class of organic contaminants that can be adsorbed onto PM and can have harmful effects on health, due to their particular chemical structure. The International Agency for Research on Cancer (IARC) classified PAHs as potential carcinogenic agents and benzo[a]pyrene (BaP) as carcinogenic to humans. In this paper, the development of a metrologically traceable procedure for the quantification of BaP in airborne PM, performed at the Italian National Institute of Metrological Research (Istituto Nazionale di Ricerca Metrologica-I.N.Ri.M.), is presented. The identification and quantification of BaP in PM samples were carried out by gas chromatography coupled with mass spectrometry (GC-MS). Metrological traceability was established in all the procedure steps, after performing the method validation. Suitable certified reference materials (CRMs) were used both to validate the analytical method and to calibrate the GC-MS. The measurement uncertainty was evaluated by identifying and taking into account all the relevant sources deriving from the whole procedure steps.