title: Development of a new procedure for the determination of captopril in pharmaceutical formulations employing chemiluminescence and a multicommuted flow analysis approach.
abstract: This paper describes a new technique for the determination of captopril in pharmaceutical formulations, implemented by employing multicommuted flow analysis. The analytical procedure was based on the reaction between hypochlorite and captopril. The remaining hypochlorite oxidized luminol that generated electromagnetic radiation detected using a homemade luminometer. To the best of our knowledge, this is the first time that this reaction has been exploited for the determination of captopril in pharmaceutical products, offering a clean analytical procedure with minimal reagent usage. The effectiveness of the proposed procedure was confirmed by analyzing a set of pharmaceutical formulations. Application of the paired t-test showed that there was no significant difference between the data sets at a 95% confidence level. The useful features of the new analytical procedure included a linear response for captopril concentrations in the range 20.0-150.0 µmol/L (r = 0.997), a limit of detection (3σ) of 2.0 µmol/L, a sample throughput of 164 determinations per hour, reagent consumption of 9 µg luminol and 42 µg hypochlorite per determination and generation of 0.63 mL of waste. A relative standard deviation of 1% (n = 6) for a standard solution containing 80 µmol/L captopril was also obtained.
authors.affiliation: Departamento de Química, Universidade Federal do Maranhão, São Luís, Brazil.
authors.forename: Manoel J A
authors.initials: MJ
authors.lastname: Lima
authors.affiliation: Departamento de Química, Universidade Federal do Maranhão, São Luís, Brazil.
authors.forename: Ridvan N
authors.initials: RN
authors.lastname: Fernandes
authors.affiliation: Departamento de Química, Universidade Federal do Maranhão, São Luís, Brazil.
authors.forename: Auro A
authors.initials: AA
authors.lastname: Tanaka
authors.affiliation: Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Piracicaba, Brazil.
authors.forename: Boaventura F
authors.initials: BF
authors.lastname: Reis
mesh_terms: D002216:Captopril / Q000032:analysis*; D002626:Chemistry, Pharmaceutical; D017022:Flow Injection Analysis; D049449:Luminescence; D004364:Pharmaceutical Preparations / Q000737:chemistry*
chemical_list: D004364:Pharmaceutical Preparations; D002216:Captopril
keywords: captopril; chemiluminescence; green chemistry; multicommuted flow analysis; solenoid mini-pumps