Abstract
A method of measurement of atmospheric sulfuric acid particles was developed by modifying a method proposed by Penzhorn and Filby (1976). This method used an assembly for the generation of diazomethane and methylation of sulfuric acid. The minimum detection of H2SO4.t was 3ng. The amount of sulfuric acid particles generated in a test chamber determined by this method agreed well with those by barium chloranilate and titration methods. On field sampling gaseous NH3; which converted H2SO4 to (NH4)2SO4 was eliminated by using an NH3 denuder.
In Tokyo, in August of 1981 the concentrations of sulfuric acid particles were 0.3-4.7μg m-3. In Sapporo they were 0.2-1.3μg m-3; between May and July in 1981, and 0.1-1.4μg m-3 between November in 1981 and January in 1982 respectively. The cumulative fraction by weight of sulfuric acid particles less than 2.1μm in diameter was 90%. The ratio of H2SO4/SO2-4 increased with decreasing particle diameter.
