A sensitive chemiluminescence flow system for the determination of sulfite

A novel chemiluminescence (CL) now system for sulfite with flow-injection analysis is presented in this paper. It is based on the wet chemiluminescence produced by auto-oxidation of sulfite in the presence of Rh6G, immobilized electrostatically on a cation exchange column. Tween 80 surfactant micelles showed a strong enhancement effect on this weak chemiluminescence. The system responds linearly to sulfite concentration in the range of 0.01-5 mg l(-1) (r(2)=0.996) with a detection limit (3 sigma) of 0.01 mg l(-1). Interfering metal ions coexisting in sample solutions could be effectively eliminated on-line by an upstream cation exchanger. A complete analysis could be performed in 1 min with a relative standard deviation of less than 5% (n=11). The system is stable for over 500 determinations and has been successfully applied to the determination of sulfite in VK3 injections and sulfur dioxide in air.