Simultaneous, detection of 8 monoamine neurotransmitters in the different sections of mouse brains by high performance liquid chromatography with fluorescence detection

A method for the simultaneous detection of L-dihydroxyphenylalanine > norepinephrine , epinephrine, dopamine, 3 ,4-dihydroxyphenylacetic acid, serotonin hydrochloride, 5-hydroxyindole-3-acetic acid and homovanillic acid in the different sections of mouse brains was established by using high performance liquid chromatography (HPLC) with fluorescence detection and isocratic elution. Before analysis, the sample was deproteinized by 0.60 moVL perchloric acid, followed by adjusting pH value of the sample with 1. 20 mol/L K2HPO4, addition of 0. 1 g/L L-cysteine as antioxidant and 0. 50 mmol/L Na(2)EDTA as complexing agent. The separation column was a Shim-pack C-18 column (250 mm x 4.6 mm 5 mu m) and the mobile phase (pH 3. 8) was 13% methanol containing 50 mmol/L citric acid, 50 mmol sodium acetate, 0. 5 mmol/L 1-heptanesulfonic acid sodium salt, 5 mmol/L triethylamine and 0.5 mmol/L Na(2)EDTA. The flow rate was 1. 0 mL/min. The injection volume was 10 mu L. The emission and excitation wavelengths were 330 nm and 280 nm , respectively. Under the optimized separation conditions , the calibration curves showed good linearity within the concentrations of 1. 25 5 000 mu g/L (r >0. 999 9). The limits of detection were between 0. 20 - 5.00 mu g/L, the average recoveries were between 94. 83% and 99. 19%, and the relative standard deviations (RSDs) were between 0.08% and 2.51%. The advantages of the method include easy and prompt operation, high recovery, low detection limit, good separation effect, high accuracy and precision. The method has practical value for detecting 8 monoamine neurotransmitters in biological samples.