[Study on monoamine neurotransmitters in rat serum and brain tissue by high performance liquid chromatography with...

A rapid, reliable and simple method detecting monoamine neurotransmitters in rat serum and brain tissue by high performance liquid chromatography with electrochemical detector was developed.

An ODS column was selected as separation column at room temperature,and the mobile phase (pH4.50) consisted of 0.02 mol/L trisodium citrate and 0.05 mol/L disodium phosphate, containing 15% methanol (volume ratio)in distilled water. The mobile phase was pumped at a flow rate of 1.0 ml/min and the oxidation potential was set at +0.065 mV. Dihydroxybenzylamine was used as the internal standard for quantification. Four compounds, epinephrine (E), dopamine (DA) and 5-hydroxytryptamine(5-HT) in the brain tissue ((whole cerebral cortex, hippocampus, striatum, midbrain, cerebellum) and serum were simultaneously separated and determined under the above conditions.

RSD of the retention times and peak areas of standard sample was in the range 0.29%-0.67% and 0.09%-0.36%. The recoveries of all analytes were over 85%. The detection limits of 0.083 ng/ml for NE, 0.51 ng/ml for E, 0.046 ng/ml for DA and 0.078ng/ml for 5-HT were achieved with standard solutions. The linearity is over the range 1.0-100 ng/ml for NE, 5.0-80 ng/ml for E,1.0-80 ng/ ml for DA and 1.0-60 ng/ml for 5-HT.

The assay had been applied successfully to measure simultaneously cortex and serum concentrations of these four monoamines in rats.