Sensitive Voltammetric Determination of Niclosamide at a disposable pencil graphite electrode

Niclosamide (NA), an effective drug against tapeworm infections, was electrochemically studied using a pencil graphite electrode (PGE). A low-cost sensitive and selective procedure was developed for determination of NA by recording differential pulse voltammograms of NA in pH 7.0 Britton-Robinson buffer solution containing 0.1 M KCl and 30% DMF at the PGE. The PGE displayed very good electrochemical behavior with significant enhancement of the peak current compared to a glassy carbon electrode. Moreover, results obtained from the differential pulse voltammograms show that PGE offers a disposable, low cost, selective and sensitive electrochemical sensor for determination of NA. Under experimental conditions, the PGE had a linear response range from 0.05 μM to 10 μM NA with a detection limit of 0.015 μM (based on 3sb). A relative standard deviation of 0.57% was obtained for five successive determinations of 5 μM NA, which indicate acceptable repeatability. This voltammetric method was successfully applied to the direct determination of NA in tablets. No interference from the tablet excipients was encountered.