Evaluation of uncertainty associated with determination of particle-bound pahs in ambient area by TD-GC/MS and Soxhlet-GC/MS

Abstract

Knowing the uncertainty associated with an analytical method is necessary to evaluating the quality of the results. In this work, the uncertainty associated with the analytical measurement of polycyclic aromatic compounds (PAHs) in ambient air using thermal desorption coupled with gas chromatography-mass spectrometry (TD-GC/MS) was evaluated. The study focused on analyses of the particulate phase (PM10), and the results were compared to those obtained with a conventional solvent extraction (Soxhlet-GC/MS). The main sources of the combined uncertainty were the calibration curve, recovery of the extraction stage, area or volume of the sample and volume of air. TD-GC/MS reported a lower combined uncertainty (< 10%) than Soxhlet-GC/MS (values between 11% and 18%) for the measurement of particle-bound PAHs in the air, which was primarily contributed by the recovery of the analyzed PAHs and the calibration curves.