MWCNT-Modified Gold Electrode Sensor for the Determination of Propyl Gallate in Vegetable Oils

A differential pulse voltammetric method for the determination of the synthetic food antioxidant, propyl gallate (PG) was developed. Determination of PG was carried out using multiwalled carbon nanotube (MWCNT)-modified gold electrode (GE) in a solution of 0.1 M acetate buffer (pH 7) as supporting electrolyte. The developed sensor showed an excellent catalytic activity and stability for PG oxidation. Effect of common interfering ions, amount of MWCNT-Nafion suspension, pH of the supporting electrolyte, and scan rate were studied. Under optimized conditions, PG concentration as low as 6.3 x 10(-7) M can be determined in food samples. The determination of PG in vegetable oils with the proposed sensor was in good agreement with those obtained by reported spectrophotometric method.