Determination of subpicogram levels of airborne polycyclic aromatic hydrocarbons for personal exposure monitoring assessment

A method based on the use of GC coupled to Q-exactive Orbitrap mass spectrometry (GC-Orbitrap-MS) has been developed for the analysis of polycyclic aromatic hydrocarbons (PAHs) at sub-picogram levels. Outdoor ambient air particulate matter (PM2.5) and standard reference materials (SRM2260a) were analyzed in full scan mode showing low instrumental uncertainties (1-22%) and high linearity over a wide concentration range (0.5 pg and 500 pg/μL). Good reproducibility was obtained compared to the use of conventional single quadrupole GC-MS of PM samples. The quantification limit of the GC-Orbitrap-MS method for full scan analysis of PAHs in outdoor ambient air PM samples was 0.5 pg/μL. This low limit allowed the analysis of PAHs in samples collected with low volumes (< 0.5 m3), such as punch samples from whole filters or filter strips from personal exposure monitoring equipment. PAHs were successfully analyzed in filter strips from real-time Aethalometer AE51 equivalent black carbon (eBC) analyzers used in urban and rural sites, and in personal exposure monitors of firefighters during prescribed burns. The correlations between PAHs and eBC in these analyses were very strong (r2 ≥ 0.93). However, the equations obtained reflected the dominance of different emission sources, such as traffic in urban areas, wood burning for domestic heating, or wildfires. The method reported here affords the analyses of PAHs in high precision studies of atmospheric PM samples, e.g., high frequency sampling of low volumes, affording personal exposure monitoring assessments.

Financial support for this study was provided by the research projects from the European Commission FIRE-RES (101037419, call H2020 LC-GD-1–1-2020–1) and the Spanish Ministry of Science and Innovation INTEMPOL (PGC2018-102288-B-I00). The Catalan Fire and Rescue Service and Generalitat de Catalunya are acknowledged for their support during the prescribed burns and PM filter supply. IDAEA-CSIC is a Severo Ochoa Centre of Research Excellence (grant CEX2018-000794-S funded by MCIN/AEI/10.13039/501100011033).

Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature.

With funding from the Spanish government through the "Severo Ochoa Centre of Excellence" accreditation (CEX2018-000794-S).

Peer reviewed