Flow-injection spectrophotometric determination of tetracycline and doxycycline in pharmaceutical formulations using chloramine-T as oxidizing agent

• Autor(a) principal: Rufino,José L.
• Data de Publicação: 2009
• Outros Autores: Weinert,Patrícia L., Pezza,Helena R., Pezza,Leonardo
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Química Nova (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0100-40422009000700016
• topic: tetracyclines; flow-injection; spectrophotometry

A flow-injection (FI) spectrophotometric procedure is proposed for tetracycline (TC) and doxycycline (DXC) determination in pharmaceuticals. The method is based on the reaction of oxidation of these drugs by chloramine-T in alkaline medium producing red color products (λmax = 535 and 525 nm). Beer´s law is obeyed in the concentration range from 6.62 x 10-5 to 7.72 x 10-4 mol L-1 and 5.37 x 10-5 to 7.16 x 10-4 mol L-1 for TC and DXC, respectively. The analytical frequency was 50 h"1 and 45 h-1 for TC and DXC, respectively. The results obtained by the proposed method were in good agreement with those obtained by the official method at 95% confidence level.