Fluorimetric detection of octopamine in high-performance liquid chromatography and its application to the assay of dopamine beta-monooxygenase in human serum.

A high-performance liquid chromatographic procedure is described for the determination of octopamine. The method, which is based on the separation on a microparticulate bonded strong cation-exchange resin and measurement of the native fluorescence, has been applied to give a sensitive assay of dopamine beta-monooxygenase (EC 1.14.17.1) activity in human serum with tyramine as the substrate. The procedure, which has been designed for use with an automatic sampler, has a detection limit of about 50 pmoles of octopamine, and the analysis time is approximately 10 min per sample.