FY 1989

Collection efficiencies of a tandem sampling system for atmospheric aerosol particles and gaseous ammonia and sulfur dioxide

Quinn, P.K., and T.S. Bates

Environ. Sci. Technol., 23(6), 736–739, doi: 10.1021/es00064a013 (1989)

The collection efficiencies of aerosol particles and gaseous NH₃ and SO₂ were tested for a tandem sampling system consisting of a cyclone separator followed by a 1.0 µm pore size 47-mm Millipore Teflon particle filter and four 47-mm Whatman 41 filters coated with oxalic acid and either K₂CO₃ or LiOH. The collection efficiency of the cyclone was compared with an 8.0 µm pore size Nuclepore filter using NaCl particles. Both the cyclone and the filter had a 50% collection efficiency at 0.9 µm (50 standard L/min, 55 cm s⁻¹ filter face velocity). Known amounts of NH₃ and SO₂ were generated and collected on the coated filters. The collection efficiency of the system for NH₃ was found to be 103 ± 30%. The SO₂ collection efficiency on K₂CO₃₋ and LiOH-coated filters was 100 ± 21 and 88 ± 9%, respectively, and was not affected by the presence of reduced sulfur gases or ozone in the sampled air stream.