Determination of amino acid neurotransmitters by high performance capillary electrophoresis in hippocampus and cerebrospinal fluid

Objective To establish an high performance capillary electrophoresis(HPCE) method for the determination of amino acid neurotransmitters,such as glutamate(GLU),aspartate (ASP),γ-amino butyrate(GABA) and glycine(GLY) in hippocampus and cerebrospnal fluid(CSF). Methods The amino acids were separated by HPCE at the voltage of 20 kV.The bare fused silica capillary was 60 cm in total length,50.5 cm in efficient length and 75 μm in diameter.The running buffer was 100 mmol/L boric acid-Tris containing 1% isopropyl alcohol(pH 10.35).Laser induced fluorescence detector was applied.The performance of methodology was evaluated.The levels of amino acids(GLU,ASP,GABA and GLY) were determined in CSF of 45 patients. Results The 4 kinds of amino acids were separated within 15 min.The linearity of the assay was from 1.0 μmol/L to 100.0 μmol/L.The minimal detection limit of GLU,ASP,GABA and GLY was 10,23,18 and 15 nmol/L respectively.For those amino acids, the within-run coefficient of variation(CV) was 4.44%-9.72% and the between-run CV was 6.96%10.50%.The recovery of amino acids was not less than(88.1%.) The levels of GLU,GLY and ASP in CSF of general epilepsy patients were significantly higher than in control group(P0.05),but the level of GABA was not significantly different;The concentrations of GLU,GLY,ASP and GABA in CSF of partial complex epilepsy were obviously higher than that in control group(P0.05). Conclusions HPCE has(many) advantages such as rapidity,simplicity,accuracy and sensitivity. The method can be used in clinical and scientific research.