Energy transfer electrogenerated chemiluminescence for the determination of sulfite

A simple and novel electrogenerated chemiluminescence (ECL) method for the determination of sulfite has been developed based on the energy transfer ECL process. It was found that a weak ECL signal of sulfite was electrochemically generated on a platinum electrode in neutral aqueous solution. The signal was strongly enhanced by rhodamine B as an energy receptor and further enhanced by the neutral surfactant Tween 80. In 0.10 M phosphate buffer solution (pH = 7.5) containing 2.0 x 10(-6) g mL(-1) rhodamine B and 0.4% (v/v) Tween 80, the ECL response to the concentration of sulfite at a potential of 0.82 V was linear over a range of 1.0 x 10(-7) g mL(-1) to 8.0 x 10(-6) g mL(-1), and the detection limit was 5 x 10(-8) g mL(-1). The relative standard deviation (n = 11, 1.0 x 10(-6) g mL(-1)) was 3.8%. The proposed method has been successfully applied to the determination of sulfite in pharmaceutical injections and white sugar samples.