|
|
The concentration of fine particulate carbonaceous material has been measured over a 1�year period at the Interagency Monitoring of Protected Visual Environments (IMPROVE) Canyonlands National Park, Utah sampling site using a Brigham Young University organic sampling system (BOSS) multisystem, multichannel diffusion denuder sampler. Samples were collected on the IMPROVE schedule of a 24�hour sample every Wednesday and Saturday. The concentrations of particulate C, determined using only a quartz filter pack sampling system, were low by an average of 39%, as a result of the loss of semi�volatile organic compounds from the particles collected on quartz filters during sampling. The loss was higher during the summer...
|
Measurement of the loss of semi-volatile organic compounds from particles collected with a filter is carried out by comparing the amounts collected by comparable filter pack and diffusion denuder samplers. The sorbents used to collect organic compounds in the denuder and sorbent filters must have the same efficiency for collection of all gas-phase organic compounds present. Interpretation of the data requires that the efficiency of collection of gas-phase compounds by the denuder be known. In theory this can be accomplished by determination of the deposition pattern of all organic compounds collected in the denuder, but in practice this is very difficult if the organic material consists of a wide variety of compounds....
|
|
