Chemiluminescence method for the direct determination of sulphur dioxide

Abstract

A method for the determination of SO₂ based on the fact that it enhances the chemiluminescence produced by the reaction of luminol with H₂O₂ has been developed. The calibration graph for SO₂ was a straight line with a correlation coefficient of 0.998 from 1 to 1000 p.p.b. (V/V). The detection limit (signal to noise ratio = 3) was 0.6 p.p.b. and the relative standard deviation for ten measurements of 10 p.p.b. of SO₂ was 5.3%. The method required 1 min or less for the determination of 10 p.p.b. of SO₂. Ozone and nitrogen dioxide interfered but were almost completely removed by using a tube packed with glass beads coated with FeSO₄. Sulphur trioxide and the other gases except H₂S did not interfere.