Cathodic Stripping Voltammetric Determination of Ferulic Acid in Chinese Angelica with Carbon Paste Electrode

Ferulic acid was determined by cathodic stripping voltammetry using carbon paste electrode as working electrode. In a 0.05 mol·L-1 HCl solution containing 0.04 mol·L-1 NaCl and 0.004 g·L-1 sodium laurylsulfonate, and by accumulation at 1.1 V (vs.SCE) for 180 s and scanning from 1.0 V to 0 V at the rate of 100 mV·s-1, a sensitive cathodic stripping voltammetric peak given by ferulic acid was observed at the carbon paste electrode at the potential of 0.46 V (vs.SCE). Linear relationship between values of peak current and concentration of ferulic acid was obtained in the range of 2.2×10-7-1.1×10-5mol·L-1, with detection limit (3S/N) of 4.0×10-8mol·L-1. A preliminary discussion on the electrochemical behavior of ferulic acid at the carbon paste electrode was given. This method was used in the determination of ferulic acid in sample of Chinese angelica, and using this sample as matrix, recovery was tested by standard addition method, giving results of recovery and RSD′s (n=6) in the ranges of 104.0%-109.1% and 2.6%-5.3% respectively.