Determination of monoamine transmitters and their metabolites by capillary electrophoresis with electrochemical detection Original Research Article

Capillary electrophoresis (CE) was employed to separate both monoamine transmitters and their metabolites in phosphate buffer, combined with electrochemical detection (ED) at a carbon disk electrode. The electrode used was a 300 μm diameter carbon disk operated in a wall–jet configuration. A sample mixture containing four different monoamine transmitters and four metabolites was separated. No uric acid (UA) and ascorbic acid (AA) interference was observed. This method showed high sensitivity and resolution. The detection limit (S/N=3) for monoamine transmitters was 1.0×10−7 mol l−1. Furthermore, microdialysis sampling was coupled with CE to determine the monoamine transmitters from the caudate nucleus (CN). This method is simple and suitable for the analysis of monoamine transmitters, with high sensitivity and reproducibility.