Stripping voltammetric behaviour of toxic drug nitrofurantoin

A simple, sensitive and reproducible squarewave cathodic adsorptive stripping voltammetric method has been developed for the determination of nitrofurantoin in solubilized system. The objective of the present paper is to investigate the redox behaviour of nitrofurantoin by using different voltammetric techniques and to establish the methodology for its determination in the presence of surfactants. Voltammograms of the drug with cetrimide in phosphate buffers of pH 2-11 exhibited a single well-defined reduction peak which may be attributed to the reduction of -NO(2) group. The reduction process is irreversible over the entire pH range studied. The mechanism of reduction has been postulated on the basis of controlled potential electrolysis, coulometry and spectral analysis. The proposed SWCAdSV voltammetric method allows the determination of nitrofurantoin in linear concentration range 2 x 10(-5) to 1 x 10(-7) mol L(-1). The lower limit of detection (LOD) and lower limit of quantification (LOQ) are 0.06 and 0.27 ng/mL, respectively.