Use of Phosphate Activated Glassy Carbon Electrode in Voltammetric Determination of Epinephrine

Phosphate activated GCE was prepared by cyclic voltammetry, and the electrochemical behavior of epinephrine (EP) at this electrode in a phosphate buffer medium of pH 6.0 was studied. A cyclic voltammetric method for determination of trace amount of EP was proposed, by which the interference of ascorbic acid to the determination of EP was effectively eliminated. A sensitive oxidation peak of EP at 0.26 V (vs.SCE) was observed. Linear relationship between values of oxidation peak current (ipa) and concentration of EP was obtained in the range of 1.0×10-6-1.2×10-5mol·L-1, with detection limit (3S/N) of 3.0×10-7mol·L-1. This method was applied to the determination of EP in injections, giving results in consistency with the labelled values. Average recovery of the method found by standard addition method was 99.7%.