Flow Injection Chemiluminescence Determination of Hydrogen Peroxide with in-Situ Electrogenerated Br₂ as the Oxidant

ABSTRACT

By designing a novel flow-through electrolytic cell, Br₂, an unstable and toxic reagent, can be produced in-situ on the near region of a platinum electrode surface by constant current oxidizing KBr in H₂SO₄ medium. At the same time, it was found that a strong CL signal was produced when the basic H₂O₂ solution was injected into the electrolytic cell. Based on this observation, a simple, rapid and selective ECL method for the determination of H₂O₂ was proposed. Factors affecting the determination of H₂O₂, including the chemical and flow-injection parameters as well as the design of flow-through electrolytic cell, were investigated, and the possible ECL reaction mechanism was also discussed. Under the optimum conditions, the ECL emission intensity was linear with H₂O₂ concentration in the range of 1.0x10⁻⁶ − 4.0x10⁻³ mol/L and with 3.5x10⁻⁷ mol/L detection limit.

Keywords::

• Electrogenerated chemiluminescence
• flow injection analysis
• Electrogenerated Br₂
• hydrogen peroxide