The method was successfully applied to the determination of ROS in a model secondary organic aerosol (SOA) system generated by ozonolysis of nicotine, as well as in secondhand tobacco smoke (SHS). ROS concentrations between 50-565 nmol m鈭? were detected in fresh SOA and SHS samples. After SHS aging for 22 h, 13-18% of the initial ROS mass remained, suggesting the presence of persistent ROS. The new method offers better stability and reproducibility along with sensitivity comparable to that of DCFH (method detection limit of 3.2 and 1.4 nmol m鈭? of equivalent H2O2 for PF and DCFH respectively). The PF probe was stable during storage at room temperature and not reactive with ozone or NOx, whereas DCFH in the particle-collecting liquid system was strongly influenced by ozone and NOx interferences. This case study provides a good basis for employing solid-phase supported PF for field measurement of specific ROS in other combustion systems (i.e. biomass burning, candles, and diesel exhaust) and environmental aerosols.