Measuring vitamin c content of commercial orange juice using a pencil lead electrode

摘要

A pencil lead successfully served as an electrode for the determination of ascorbic acid in commercial orange juice. Cyclic voltammetry was used as an electrochemical probe to measure the current produced from the oxidation of ascorbic acid with a variety of electrodes. The data demonstrate that the less expensive pencil lead electrode gives results that are comparable to those of a more expensive commercial carbon electrode. The level of vitamin C measured was higher than the daily intake recommended by Health Canada and the United States Food and Drug Administration, which is 60 mg/day for a healthy adult. The detection limit of the pencil lead electrode was also determined.