Evaluation of an annular denuder for atmospheric PAH partitioning studies—2: evaluation of mass and number particle losses

Transmission efficiency of particles through an eight-channel annular denuder coated with XAD-4 was experimentally determined for particles ranging between 0.04 and 8.24 μm. Two sampling flow rates were tested, 17 and 34 l min−1. The results show that the mean transmission efficiencies in number are, respectively, 96% and 95% for a sampling flow rate of 17 and 34 l min−1 (particle size ranging between 0.04 and 8.24 μm), while in mass it is, respectively, 84 (±14)% and 81 (±21)% for a sampling flow rate of 17 and 34 l min−1. A comparison between these experimental results and theoretical transmission calculations shows that XAD-4 coating has no significant effect on the transmission efficiency.