Determination of conjugated dopamine in cerebrospinal fluid from humans and non-human primates with high performance liquid chromatography using electrochemical detection.

A simple and reliable procedure for the determination of conjugated dopamine (DA) in cerebrospinal fluid (CSF) is described. The conjugate, presumably a sulfate, is conveniently hydrolyzed in 0.4 M sulfuric acid at 95 degrees. Thereafter, dopamine is quantitated using HPLC with electrochemical detection. Sensitivity (0.5 pmol/ml) is sufficient for clinical studies. Only 400 ul of CSF are required for the assay. The within assay coefficient of variation was 3.2% for conjugated DA (concentration of 11.8 pmol/ml). In a material consisting of 261 samples of lumbar CSF from unmedicated psychiatric patients and normal control subjects, a concentration range of 1.3-21.7 pmol/ml was found. No clear differences were evident between the major diagnostic groups.