Determination of Sulfur Dioxide Content of the Atmosphere (Hydrogen Peroxide Method)

Sulfur dioxide is absorbed by aspirating a measured volume of air through a solution of dilute hydrogen peroxide (1). Sulfur dioxide is oxidized by hydrogen peroxide to sulfuric acid. The oxidation of S(IV) (dissolved SO₂) to S(VI) (sulfate) by H₂O₂ is very fast (2). The sulfate collected in the absorber solution may be determined by any method suitable for aqueous sulfate (see 720. DETERMINATION OF AQUEOUS SULFATE).