Chemiluminometric determination of captopril in a multi-pumping flow system

• Tipo: Artigo em Revista Científica Internacional
• Data: 2012

Autores

Sofia S M Rodrigues (Autor) Outra; Joao L M Santos (Autor) FFUP

Revista

Título: Talanta

Vol. 96

Páginas: 210-215

ISSN: 0039-9140

Editora: Elsevier

Indexação

ISI Web of Knowledge - 21 Citações

Scopus - 24 Citações

Classificação Científica

FOS: Ciências exactas e naturais > Química

Outras Informações

ID Authenticus: P-002-7Z6

DOI: 10.1016/j.talanta.2012.02.016

Abstract (EN): In this work, a simple, versatile and fully automated analytical methodology for the chemiluminometric determination of captopril - an angiotensin II-converting-enzyme (ACE) inhibitor - in pharmaceutical formulations, is proposed. The developed methodology was based on the enhancement by captopril of the chemiluminescence emission of tris(2,2'-bipyridyl)ruthenium(II). In sulphuric acid medium tris(2,2'-bipyridyl)ruthenium(II) was oxidized by cerium(IV) and converted into a reactive oxidant specie [Ru(bpy)(3)](3+), which was subsequently reduced with captopril in order to yield a significant enhancement of the original chemiluminescence emission that was directly related to captopril concentration. The analytical process was implemented by resorting to an automated multi-pumping flow system (MPFS) that enabled the establishment of multiple reaction interfaces, which, in combination with the created pulsed flowing stream assured a fast and reproducible sample/reagent mixing and reaction development essential to guarantee the generation and subsequent measurement of the short-lived species involved in the chemiluminescent process. The developed system employed three solenoid micro-pumps as the only flow manifold active components. These assured the insertion, propelling and commuting of all solutions. The automatic actuation of the solenoid micro-pumps provided an easily programmed, operated and controlled analytical flow system, exhibiting high versatility, efficiency and compactness at a low cost. Under the optimized experimental conditions, the proposed method allowed the determination of captopril for concentrations between 2 x 10(-3) and 1.5 x 10(-1) mmol L-1 (r = 0.9996, n = 6) and a sampling frequency of about 58 determinations per hour, producing 620 mu L of waste per determination. The results obtained for pharmaceutical formulations were statistically comparable to those provided by the reference procedure with a relative deviation between -2.32 and 1.39%. The possible mechanism of the chemiluminescence reaction was also discussed in this work.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 6