Development of a High-Sensitivity LC-MS Orbitrap Eclipse Methodology for the Detection of PAH Derivatives

Polycyclic aromatic hydrocarbons (PAHs) and their derivatives, such as nitro-PAHs and oxygenated PAHs (oxy-PAHs), are persistent organic pollutants with significant environmental and health impacts. PAHs are primarily emitted through incomplete combustion processes and are well-recognized for their carcinogenic and mutagenic potential. While most studies have focused solely on the 16 parent PAHs classified by the US-EPA (US Environmental Protection Agency), PAH derivatives remain underexplored due to analytical difficulties, including low environmental concentrations and complex sampling matrices.

For these reasons, a methodology for analyzing nitro and oxy-PAHs in atmospheric matrices was developed on an HR-MS (LC-MS Orbitrap Eclipse) using an Atmospheric Pressure Chemical Ionization (APCI) in both positive and negative modes with a resolution of 60 000. This method demonstrated excellent sensitivity, achieving a detection limit of 0,03 ng m^-³ for targeted PAH derivatives with a calibration range extended from 0.3 µg L^-1 to 15 µg L^-1 equivalent to 0.03 ng m^-3 to 1.5 ng m^-3 (considering an air sample volume of 10 m³ and a sample volume of 1 mL after extraction and concentration) with excellent linearity (correlation coefficient >0.99), ensuring the accuracy and reliability of quantification across a wide concentration spectrum. The technique also incorporated rigorous validation steps, including precision, robustness, and accuracy to confirm its reliability for trace-level measurements.

Finally, the methodology was applied to emissions from different asphalt formulations using a laboratory prototype that simulates road asphalt production conditions. Filters were collected, extracted, and analyzed using LC-MS Orbitrap. This enabled the detection and analysis of specific (PAHs) and their derivatives, demonstrating its capability to simultaneously identify and quantify a wide range of these compounds.