Polarographic determination of nitrofurazone and furazolidone in pharmaceutical formulations and urine

Abstract

In pyridine-formic acid buffer and tetramethylammonium chloride solution over the pH range 0–8.5, nitrofurazone, furazolidone and other nitrofuran derivatives are reduced in a six-electron process, giving rise to a well defined polarographic reduction wave at a dropping mercury electrode. The current is diffusion controlled and proportional to the concentration from about 5.88 × 10^–3 M to the limit of detection of 1.24 × 10^–6 M. The proposed method permits these drugs to be determined, without any prior separation or extraction, in pharmaceutical formulations and in urine at levels at which the unchanged drugs are excreted. Other drugs commonly used as therapeutic agents, such as nitro derivatives of 1,4-benzodiazepines, chloramphenicol, metronidazole and tinidazole, are reduced in a single four-electron process at more negative potentials, which makes simultaneous determinations possible.