High-performance liquid chromatography with amperometric detection applied to the screening of 1,4-dihydropyridines in human plasma.
A high-performance liquid chromatographic method with electrochemical detection has been developed for the determination of six 1,4-dihydropyridines: nifedipine, nimodipine, nisoldipine, nicardipine, felodipine and lacidipine. The chromatographic separation was performed using a Supelcosil LC-ABZ+Plus C18 column. A mobile phase of methanol-water (70:30), containing 2 mM CH3COOH-CH3COONa at a flow-rate of 1 ml/min and a pH of 5.0, was used. The temperature was optimized at 30+/-0.2 degrees C. The amperometric detector, equipped with a glassy carbon electrode, was operated at 1000 mV versus Ag/AgCl in the direct current mode. The method was applied to the determination of these compounds at ng/ml concentrations, obtaining intra-day reproducibilities of lower than 5.0% in terms of relative standard deviations and detection limits ranging from 16 to 44 ng/ml. The method was applied to the screening of 1,4-dihydropyridines in spiked plasma samples, with a total elution time of lower than 18 min, obtaining the best recoveries for nimodipine and felodipine (91 and 88%, respectively). These recoveries together with the low detection limits achieved allow its application to the analysis of these drugs in human plasma.
López
J A
JA
Departamento de Química Analítica, Facultad de Ciencias, Universidad del País Vasco, Bilbao, Spain.
Martínez
V
V
Alonso
R M
RM
Jiménez
R M
RM
D002121:Calcium Channel Blockers / Q000097:blood*; D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004095:Dihydropyridines / Q000097:blood* / Q000737:chemistry; D004355:Drug Stability; D004563:Electrochemistry; D006801:Humans; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D002121:Calcium Channel Blockers; D004095:Dihydropyridines; C038806:1,4-dihydropyridine