title: Development and validation of a selective and robust LC-MS/MS method for quantifying amlodipine in human plasma.
abstract: A liquid chromatographic-tandem mass spectrometric method (LC-MS/MS) for quantifying amlodipine in human plasma was developed and validated. Sample preparation was based on liquid-liquid extraction using NaOH and a mixture of ethyl acetate/hexane (80/20; v/v). Chromatography was performed on a C-18 analytical column and the retention times were 1.9 and 3.0 min for amlodipine and nimodipine (internal standard), respectively. The ionization was optimized using ESI(+) and enhanced selectivity was achieved using tandem mass spectrometric analysis via two MRM functions, 409 --> 238 and 418 --> 343 for amlodipine and nimodipine. The calibration curve ranged from 0.2 to 20.0 ng/mL. The inter-day precision and accuracy and the relative standard deviation (RSD) were <15%. The analyte was shown to be stable over the time-scale of the whole procedure. The robustness of the method was demonstrated by the good reproducibility of the results obtained during the analysis of clinical samples.
authors.affiliation: Clinical Pharmacology and Gastroenterology Unit, São Francisco University Medical School, Av. Sao Francisco de Assis 218, 12916-900 Bragança Paulista, SP, Brazil.
authors.forename: P
authors.initials: P
authors.lastname: Massaroti
authors.forename: L A B
authors.initials: LA
authors.lastname: Moraes
authors.forename: M A M
authors.initials: MA
authors.lastname: Marchioretto
authors.forename: N M
authors.initials: NM
authors.lastname: Cassiano
authors.forename: G
authors.initials: G
authors.lastname: Bernasconi
authors.forename: S A
authors.initials: SA
authors.lastname: Calafatti
authors.forename: F A P
authors.initials: FA
authors.lastname: Barros
authors.forename: E C
authors.initials: EC
authors.lastname: Meurer
authors.forename: J
authors.initials: J
authors.lastname: Pedrazzoli
mesh_terms: D017311:Amlodipine / Q000032:analysis*; D002853:Chromatography, Liquid / Q000295:instrumentation / Q000379:methods; D006801:Humans; D015394:Molecular Structure; D012680:Sensitivity and Specificity; D053719:Tandem Mass Spectrometry / Q000295:instrumentation / Q000379:methods*
chemical_list: D017311:Amlodipine