Separation and quantitation of the amino acid neurotransmitters in rat brain by capillary electrophoresis

Capillary electrophoresis (CE) has been used to separate the CBI derivatives of the neurotransmitters gamma-aminobutyric acid, glycine, glutamate, aspartate, norepinephrine and dopamine from 18 other amino acids present in the rat brain. The procedure, which requires an injection volume of < 10 nl, gave detection limits of 24-40 fmol using UV detection at 420 nm. Efficiencies for the derivatized amino acids varied from 344,000 to 444,000 theoretical plates. The method was applied successfully to the quantitation of the amino acid neurotransmitters and several other amino acids in a rat brain homogenate.