Influência de processos antagônicos no desenvolvimento de sistema de análises em fluxo para a determinação espectrofotométrica de propiltiouracil em medicamentos Influence of antagonic processes on the development of flow analysis system for spectrophotometric determination of propylthiouracil in medications

• Main Authors: Rodolfo de Melo Magalhães Santana, Mauro Korn, Josué Carinhanha Caldas Santos
• Format: Article
• Language: English
• Published: Sociedade Brasileira de Química 2013-01-01
• Series: Química Nova
• Subjects: tautomeric equilibrium; antagonist processes; propylthiouracil
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-40422013000100017

<abstract language="eng">A multi-commuted flow system was developed to determine propylthiouracil (PTU) based on the reaction of its thiol form with iminoquinone radical generated by the oxidation of N,N-dimethyl-p-phenylenediamine in an alkaline medium. PTU can be found in tautomeric forms and the tautomeric equilibrium was displaced to enhance the thiol form. However, the reaction product is unstable and its residence time in the flow path was carefully investigated. The proposed procedure showed good precision (< 1.5%) and a limit of detection (3s) of 0.11 mg L-1. High recoveries were obtained in the validation test. The procedure was employed for propylthiouracil determination in medications.