| Monoamine transmitters, including epinephrine, norepinephrine, dopamine and 5-hydroxytryptamine, are important natural molecules that play significant functional roles in the mammalian central nervous system. The study of these substances has sparked interest due to its relevance to various pathological conditions.In this thesis, a method based on high-performance liquid chromatography with a coulometric electrode array system (HPLC-CEAD) has been developed for the rapid simultaneous determination of these substances in mice brain. The procedure was notably improved by modifications of sample pretreatment and the chromatographic conditions.Mice were killed by cervical dislocation; the brains were removed and dropped into ice-cold saline immediately. Tissue samples after dissection were frozen on dry ice and analyzed immediately. Brain sample were weighed before homogenizing with perchloric acid (0.1mol/L). The homogenate was centrifuged twice at 4°C for 10min at 10,000×r/min. The supernatant was collected and filtered through 0.22μm Acrodisc filter before detection. The mobile phase was 50mmol/L sodium acetate (pH 5.0) and methanol. Elution was performed by linearly increasing the methanol concentration from 4% to 15% in the first 15 minutes and maintaining it at 15% in the next 8 minutes. The flow-rate was kept constant at 1.0 ml/min. Potentials of four electrodes in series were set at 0, 200, 500 and 700mV, respectively. The detection limits were 2-8ng/ml. Recoveries for the nine compounds in spiked samples were over 90%.The method was validated thoroughly in this thesis, and the result exhibited enhanced specificity, accuracy and repeatability. This method was aslo easy to operate, convenience to achieve, and suited for routine monitoring of monoamine transmitters in biological fluids.
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