[Determination of 4-aminobutyric acid in pumpkin powder by high performance liquid chromatography]

A method for the separation and determination of the 4-aminobutyric acid in pumpkin powder by high performance liquid chromatography (HPLC) with post-column derivatization and fluorescence detection is described. The operating conditions were cation exchange resin column (30 cm x 0.4 cm i.d.) with gradient elution of buffer solutions A [19.6 g sodium citrate dihydrate and 1.0 g phenol dissolved in 1 L water, pH(3.15 +/- 0.02)] and B [21.0 g sodium nitrate and 1.5 g boric acid dissolved in 1 L water, pH(9.70 +/- 0.02)] as mobile phase at a flow rate of 0.5 mL/min, and a column temperature of 62 degrees C, with detection wavelength lambda ex = 338 nm, lambda em = 425 nm. The retention time of 4-aminobutyric acid was 34.77 minutes. The average recovery was 99% and the coefficient of variation was 1.35%. This method is simple, rapid and sensitive.