Electrochemical Determination of Sunset Yellow Based on an Expanded Graphite Paste Electrode

A novel and sensitive electrochemical method was proposed for the determination of Sunset yellow (SY) using an expanded graphite paste electrode (EGPE). The EGPE was prepared by mixing expanded graphite (EG) with solid paraffin. EG was characterized with scanning electron microscopy. Compared with flake graphite paste and carbon paste electrode, the EGPE showed a higher electrocatalytic activity toward the oxidation of SY. The EGPE exhibited wide linear response of 5.0 × 10−8−2.0 × 10−6 mol/L with a detection limit down to 5.0 nmol/L (S/N = 3) and good accuracy, precision, reproducibility. The proposed method was successfully applied in the determination of SY in jelly and fruit juice.