A Validated HPLC Method for the Determination of GABA by Pre-Column Derivatization with 2,4-Dinitrofluorodinitrobenzene and Its Application to Plant GAD Activity Study

Abstract A validated, selective, and sensitive chromatographic method for determination of γ-aminobutyric acid (GABA) has been developed by precolumn derivative of the sample with 2,4-dinitrofluorodinitrobenzene (FDNB). The derivatives were separated with RP-HPLC on a C18 column and UV detection (360 nm). The calibration curve was linear over a range of 0.2–5.0 mg/mL GABA with a correlation coefficient of 0.9954. The precision of this method is high (RSD = 0.061%). This method also possessed high recovery rate (>99%) and good stability over a period of four weeks. The method was successfully used to determine the glutamate decarboxylase (GAD) activity in several plant tissues. Keywords: γ-aminobutyric acid2,4-dinitrofluorodinitrobenzeneGlutamate decarboxylaseHPLCPre-column derivatization reaction This work was financially supported by the Program for New Century Excellent Talents in University (Project number NCET-06-0488), the National Natural Science Foundation of China (Project number 20671044), and the Young Food Scientist Research Award of Jiangnan University. The authors are thankful to Mr. T. Guanjun for his support in MS identification.