Electrochemical Oxidation and Analytical Applications of Cholesterol at Modified Carbon Paste Electrode

The present paper describes the carbon paste electrodes modified with parafin oil and oleic acid, and the electrochemical oxidation of cholesterol at these modified electrodes. A few years ago, an oleic acid modified carbon paste electrode was proposed and applied to the selective determination of estrogens. Basing on the similar considerations, we found that cholesterol has about the same structure as estrogens. The results of voltammetric measurement indicated that cholesterol at the modified carbon paste electrodes employing the oleic acid as the modifying reagent can yield a sensitive electrochemical response. A detection limit of 1.5×10^-7mol/L cholesterol was estimated after a time of 4 min. by 1.5 order differential stripping analysis. The peak current is linearly proportional to the cholesterol concentration in the range of 3.O×10^-5——5.0×10^-7mol/L.