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

• Autor(a) principal: Rufino, José L. [UNESP]
• Data de Publicação: 2009
• Outros Autores: Weinert, Patrícia L. [UNESP], Pezza, Helena Redigolo [UNESP], Pezza, Leonardo [UNESP]
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://dx.doi.org/10.1590/S0100-40422009000700016; http://hdl.handle.net/11449/26292
• 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 (lambda(max) = 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.