A Sensitive Chemiluminescence Flow System for the Determination of Sulfite

ABSTRACT

A novel chemiluminescence (CL) flow system for sulfite with flow-injection analysis is presented in this paper. It is based on the weak 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 1⁻¹ (r²=0.996) with a detection limit (3σ) of 0.01 mg 1⁻¹. 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.

Keywords::

• FIA
• Chemiluminescence
• Immobilized reagent
• Sulfite
• Sulfur dioxide