title: Flow injection analysis with amperometric detection of naltrexone in pharmaceuticals.
abstract: Flow injection analysis (FIA) with amperometric detection using a carbon paste electrode is applied to the determination of naltrexone. The sample solution was injected into the carrier stream of 0.1 M perchloric acid, being determined by oxidation at +1.0 V vs. Ag/AgCl/sat. KCl using a flow rate of 4 ml min-1. A relative standard deviation of 1.5% was calculated for a concentration level of 10(-5) M (n = 17) without carrying out a carbon paste electrode pretreatment. Calibration curves were found to be linear between 2 x 10(-8) and 10(-5) M (almost three orders of magnitude) and the method has a detection limit of 2 x 10(-8) M. A simple and reproducible procedure is proposed for the determination of naltrexone in pharmaceuticals. The results compared favourably with those obtained by an HPLC-UV method.
authors.affiliation: Departamento de Química Física y Analítica, Universidad de Oviedo, Asturias, Spain.
authors.forename: M T
authors.initials: MT
authors.lastname: Fernández-Abedul
authors.forename: A
authors.initials: A
authors.lastname: Costa-García
mesh_terms: D002626:Chemistry, Pharmaceutical; D004563:Electrochemistry; D017022:Flow Injection Analysis / Q000379:methods; D009271:Naltrexone / Q000032:analysis*; D009292:Narcotic Antagonists / Q000032:analysis*; D011786:Quality Control
chemical_list: D009292:Narcotic Antagonists; D009271:Naltrexone