Determination of metronidazole in pharmaceutical dosage forms based on reduction at graphene and ionic liquid composite film modified electrode

An electrochemical method has been successfully demonstrated for sensitive determination of Metronidazole (MTZ) with graphene (Gr)-room temperature ionic liquid (IL) of 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF6) composite modified glassy carbon electrode (GCE). The cyclic voltammetric results indicate that Gr-IL/GCE can remarkably enhance electrocatalytic activity towards the reduction of MTZ in neutral solutions. MTZ produce a cathodic peak at about −0.69 V at this electrode. The electrochemical parameters of MTZ in the composite film were carefully calculated with the results of the charge transfer coefficient (α) as 0.625 and the number of electron transferred (n) as 4. The electrocatalytic behavior was further exploited as a sensitive detection scheme for the MTZ determination by differential-pulse voltammetry (DPV). Under optimized conditions, the concentration range and detection limit were 1.0 × 10−7–2.5 × 10−5 mol L−1 and 4.7 × 10−8 mol L−1 (S/N = 3), respectively for MTZ. The method was successfully applied assay of the drug in the pharmaceutical dosage forms.