Determination of γ-aminobutyric acid in broth of fermentation by high-performance liquid chromatography

A method for determination of γ-aminobutyric acid(GABA) in broth of fermentation by high-performance liquid chromatography was established.The broth of the fermentation was firstly pretreated with 7% (V/V) acetic acid,and then was derivatized with phenyl isocyanate(PITC).The ramifications were subsequently separated and assay by HPLC using reversed phase C18 column at 254 nm and 27°C.Under the conditions described above,PTC-GABA was well-separated and the calibration curve for PTC-GABA kept linear at 0～1.5 mmol/L.The regression equation of the calibration curve for PTC-GABA was y=14106.5713x-258.2493(r=0.9993).The limit of quantitation,relative error and average recovery of the method were 0.5 μmol/L(RSD≤10%),3.571% and 99.038%,respectively.The results indicated the method described was a sensitive,reproducible and specific assay for the determination of GABA in the broth of fermentation.