Determination of atmospheric sulfur dioxide by differential-pulse polarography using selenite

Abstract

The reaction between SO₂ and selenite ion is quantitative in 3.0–4.0 mol dm^–3 acidic solution. This reaction has been used for the determination of atmospheric SO₂. Air is passed through a selenite solution of known concentration for 10 min. The amount of selenite reacting with SO₂ is determined by differential-pulse polarography. The SO₂ concentration is proportional to the change in selenite concentration. The proposed method has been applied to authentic air samples, and the results obtained were consistent with those of other methods.