抄録
A simple assay method for selective, highly sensitive, simultaneous determination of catecholamines, indoleamines and related metabolites in the central nervous system by high-performance liquid chromatography with a series of multiple coulometric detectors (HPLC-multiple coulometric detector) was investigated. For good separation of the analysanda (eleven compounds) and internal standards, aμ BONDAPAC C18 reversed-phase column and a mobile phase consisting of a 0.04M phosphate-0.04M citrate mixed buffer (pH3.0) containing 7.5mM sodium 1-heptanesulphonate, 0.08mM ethylenediaminetetraacetic acid, 11.7% methanol and 4.7% acetonitrile were used. Also, the selective, highly sensitive and simultaneous detection of these neurochemical substances was performed with the redox-reductive screen mode using a series of three coulometric working electrodes (CWE) . In this detection system, the first and second CWE were set at +0.35V and +0.05V, respectively, for the prereaction and to prevent interference; the third CWE was used as an electrode for actual measurement, with its potential set at -0.35V against a palladium reference electrode. The assay limit was 0.5-5.0pg. Excellent chromatograms of catecholamines, indoleamines and related metabolites were obtained within 25 min. The usefulness of the HPLC-multiple coulometric detector system with the redox-reductive screen detection mode was confirmed by application to the determination of concentration levels of catecholamines, indoleamines and related metabolites in crude perchloric acid extracts of rat brain and spinal cord regions. These findings suggest that the HPLC-multiple coulometric detector system with the redox-reductive screen detection mode is useful for the study of neurochemical functions of active substances in the central noradrenergic, dopaminergic and serotonergic nervous systems.
