Abstract
We have developed an HPLC system for the simultaneous determination of neurotransmitters such as catecholamines, serotonin, and their precursors and metabolites. This system consists of two reversed-phase columns, a column switching device, a pair of electrodes for elimination of interferents and two sets of new electrochemical detectors with four electrodes. Using this system, adequate separation of peaks for 17 kinds of neurotransmitters in a standard solution required only 17 min. Norepinephrine (NE), 4-hydroxy-3-methoxyphenylethyleneglycol (MHPG), 3, 4-dihydroxyphenylacetic acid (DOPAC), 5-hydroxyindoleacetic acid (5-HIAA), homovanillic acid (HVA) and tryptophan (TRP) levels in cerebrospinal fluid (CSF) were determined without any pretreatment of CSF samples. The between-day CVs were less than 5% for all analytes in CSF. The analytical rates of recoveries were between 91 and 101%. CSF samples from patients with Alzheimer's disease, vascular dementia and Parkinson's disease were analyzed, and it was found that the concentrations of DOPAC, 5-HIAA and HVA were significantly lower in CSF of patients with these diseases than in CSF of the age-matched controls.
