Highly sensitive assay for the measurement of serotonin in microdialysates using capillary high-performance liquid chromatography with electrochemical detection

A highly sensitive isocratic capillary high-performance liquid chromatographic (HPLC) method with electrochemical detection (ED) for the simultaneous measurement of serotonin (5-hydroxytryptamine, 5-HT) and its metabolite 5-hydroxyindole-3-acetic acid (5-HIAA) in microdialysates has been developed using a 0.5 mm i.d. capillary column and a 11-nL detection cell. This method, validated on both pharmacological and analytical bases, can be performed using injection volumes as low as 1 μL. The limits of detection were 5.6 × 10−11 mol/L and 3.0 × 10−9 mol/L for 5-HT and 5-HIAA. Several applications of the present method are given on microdialysates from rodent brain and human spinal cord.