Flow-injection chemiluminescence determination of sulfite using on-line electrogenerated silver(II) as the oxidant

A novel chemiluminescence (CL) flow system for the determination of sulfite is described. It is based on the direct CL reaction of sulfite and silver( II) in acid media without any sensitizers. The unstable Ag(II) is on-line e lectrogenerated via a positive Pt-electrode from AgNO3 in HNO3 medium by co nstant current electrolysis, resulting in the elimination of the inconvenie nce of its instability to water. The CL intensity emission intensity was li near with sulfite concentration in the range 4 x 10(-7)-1 x 10(-5) mol/l; t he detection limit was 1.7 x 10(-7) mol/l (3 sigma). The system was applied satisfactorily to the determination of sulfite dioxide in air. (C) 2001 El sevier Science B.V. All rights reserved.