Liquid chromatographic determination of γ-aminobutyric acid in cerebrospinal fluid using 2-hydroxynaphthaldehyde as derivatizing reagent

gamma Aminobutyric acid (GABA) was determined by precolumn derivatization with 2-hydroxynaphthaldehyde and elution was made using Phenomenex C18, 5 μm column with methanol: water (62:38 v/v) and UV detection at 330 nm. In a mixture containing glycine, l-lysine and tyramine GABA separated completely. A number of amines and amino acids tested did not affect the response of GABA. A linear calibration curve was obtained for GABA in the range of 1.2–28.0 μg/ml with detection limit of 2.8 ng/injection (5 μl). The method was used for the determination of GABA in cerebral spinal fluid (CSF) samples and gave results of 19.0 to 22.4 μg/m1 with coefficient of variation 2.4%