All the experiments to validate the method were carried out
with hippocampus samples of male Wistar rats. Fig. 1 (panels A, B, C
and D) represents the chromatogram profiles of the OPA derivatives
of standard solutions of GABA and glutamate, a blank sample and
a hippocampus sample, respectively. Determination of the concentration
of neurotransmitters in standard solutions and biological
samples were made by calculating the area under the peak of the
chromatogram. Mean elution times for glutamate and GABA were
3.10 and 8.22 min, respectively. Thus, in a total runtime of less than
9 min both neurotransmitters were eluted in the isocratic HPLC
system using a pre-column OPA derivatisation.