RESUMEN
A chemiluminescence (CL) detection of catecholamines [norepinephrine (NE), epinephrine (E), dopamine (DA) and L-dopa (LD)] is described for the flow-injection (FI) and high-performance liquid chromatographic (HPLC) determination of these compounds. The detection method is based on the inhibition effect of catecholamines (CAs) on the CL reaction of luminol with iodine in the alkaline medium. The proposed FI method allows the determination of CAs in pharmaceutical preparations for the purpose of drug quality control. The calibration curves show good linearity in the concentration range of: 1.1-20.0 microg l(-1) (NE), 0.5-5.0 microg l(-1) (E), 0.6-9.0 microg l(-1) (DA) and 0.6-10.0 microg l(-1) (LD). The limits of detection (defined as a signal-to-noise ratio of 3) are: 0.34 microg l(-1) (NE), 0.15 microg l(-1) (E) and 0.18 microg l(-1) (DA, LD). The HPLC procedure was successfully applied for the determination of catecholamines (NE, E, DA) in human urine after solid-phase extraction (SPE). In a simple run time CAs can be determined in 20 min. The chromatographic linear ranges are: 5.0-72.0 microg l(-1) (NE), 5.0-48.0 microg l(-1) (E) and 5.0-96.0 microg l(-1) (DA). The limits of detection for three urinary CAs are: 0.71 microg l(-1) (NE), 0.26 microg l(-1) (E) and 0.73 microg l(-1) (DA).
Asunto(s)
Catecolaminas/análisis , Cromatografía Líquida de Alta Presión/métodos , Mediciones Luminiscentes/métodos , Adulto , Catecolaminas/orina , Dopamina/análisis , Dopamina/orina , Epinefrina/análisis , Epinefrina/orina , Femenino , Análisis de Inyección de Flujo/métodos , Humanos , Concentración de Iones de Hidrógeno , Levodopa/análisis , Levodopa/orina , Mediciones Luminiscentes/instrumentación , Luminol/química , Norepinefrina/análisis , Norepinefrina/orina , Estándares de Referencia , Espectrofotometría Ultravioleta , Factores de TiempoRESUMEN
A novel flow-injection method (FIA) for the determination of dopamine based on the inhibition of the intensity of chemiluminescence (CL) from luminol-hexacyanoferrate(III) system in basic medium is described. The present method allows the determination of dopamine over the range 30-100 microg l(-1) and 400-3000 microg l(-1). The relative standard deviation is 2.32% for 70 microg l(-1) dopamine and 1.22% for 1500 microg l(-1) dopamine (n = 20). The detection limit is 5 microg l(-1) with the sampling rate of 135 samples h(-1). This method has been applied for the determination of dopamine in commercial pharmaceutical injection samples. The results obtained by this method agreed with those by the official method.