Flow injection determination of metronidazole through spectrophotometric measurement of the nitrite ion produced upon alkaline hydrolysis

A new method for metronidazole determination, based on spectrometric monitoring of a diazonium salt produced in-line by alkaline hydrolysis released nitrite ions, was developed and successfully applied to pharmaceutical tablets (r = 0.9993, 2.0-20.0 mg L-1, DL = 0.7 mg L-1) with no interference from common ingredients accompanying the drug. Um novo método para determinação de metronidazol, baseado no monitoramento espectrométrico do sal de diazônio produzido in-line pelos íons nitrito, liberados numa hidrólise alcalina, foi desenvolvido e aplicado com sucesso a comprimidos (r = 0,9993, 2,0-20,0 mg L-1, LD = 0,7 mg L-1), sem interferência de ingredientes comumente presentes.