Development of a Sampling Procedure for Large Nitrogen- and Sulfur-Bearing Aerosols

摘要

So that reliable estimates of the loads of nitrogen and sulfur associated with dry deposition can be made, scientists at the U.S. EPA and elsewhere have been working to develop quantitative methods to sample and analyze the major nitrogen- and sulfur-containing species present in gaseous and aerosol form in ambient air. The objective of the research investigation was to develop a sampling procedure for large aerosols that would: (1) permit accurate determination of the mass and chemical composition of large particles present in ambient air over a 24-hour period; (2) employ a device that could be used in conjunction with an annular denuder and filter pack without interference in the determination of the gaseous and fine-particle constituents; (3) avoid the formation of chemical artifacts; and (4) be simple enough to deploy in a nationwide monitoring network.