Polarographic Catalytic Wave of Prednisone in the Presence of Persulfate and its Application

 A polarographic catalytic wave of prednisone in the presence of K₂S₂O₈ was observed. The polarographic catalytic wave of prednisone as catalyst was attributed to such chemical reaction parallel to electrode reaction as oxidized the free radical from one electron reduction of the Δ^1,4-3 keto group of prednisone to regenerate the original keto group. The catalytic wave can be used for the determination of prednisone with the help of conventional polarographic equipment, such as linear-potential scan polarograph. In 0.12 mol l⁻¹ HAc-0.08 mol l⁻¹ NaAc-0.014 mol l⁻¹ K₂S₂O₈ (pH 4.6) supporting electrolyte, the second-order derivative peak current of the catalytic wave was rectilinear to prednisone concentration in the range of 3.2 × 10⁻⁷∼1.6 × 10⁻⁵ mol l⁻¹. The detection limit was 8.0 × 10⁻⁸ mol l⁻¹. Received August 6, 2001; accepted April 17, 2002; published online July 22, 2002