ABSTRACT
Collection of suspended particulate matter in the air utilizes principles very different from those in the collection of gases. This chapter provides a brief review of pollutant collection techniques used in air sampling. It also provides information on proper sampling equipment and techniques. Before continuous air monitoring instruments were developed, gas–liquid absorption was the technique used for nearly all gaseous air pollutant sampling. Van der Waals' nonideal gas molecular interaction forces also play an important role in physical adsorption. Physical adsorption is generally reversed (desorption) by: high temperature, or by solvent rinsing. Both of these techniques are used in air sampling adsorption. Some newer and important air sampling methods include condensation or cryogenic sampling and whole air sampling. Air filtration involves a number of collection mechanisms; filters for removal of suspended particles from air that do not function primarily by sieving, but rather by diffusion, direct interception, and/or inertial collection.
