Outlined by Barb Turpin (turpin@aesop.Rutgers.edu)
Note on the use of denuders: Use of a denuder has the potential to provide more accurate particulate carbon values but a denuder must be used with caution as denuder collection efficiency varies substantially with the organic composition of the gas-particle mixture, temperature, and the presence of competing species such as water vapor. The denuder collection efficiency must be determined with real gas-particle mixtures at the sampling location. This can be done by sampling particle-free ambient air with a denuder-adsorbent combination in Port 1 and an adsorbent only in Port 2. The denuder collection efficiency is the difference between the OC loading on adsorbents in Port 2 and Port 1divided by the OC measured on the adsorbent in Port 2. (See Turpin et al., Atmos. Environ., 34, 2983 – 3013 for further information on the use of denuders and other issues in sampling and analyzing for OC and EC).