γ-aminobutyric acid (GABA) had a unique reaction with bromcresol green when glyoxylic acid and succinic acid were present with them. A new colorimetric method for rapid determination of GABA was developed based on the reaction above. The optimal concentrations of bromcresol green , glyoxylic acid and succinic acid in the chromogenic agent were 0.5, 4.0 mg/mL and 6.0 mg/mL respectively. The optimal condition for determination of GABA was that 4 mL sample was mixed with 2 mL chromogenic agent , and the absorbance of the mixed solution was determined in a spectrophotometer at 617 nm after it was kept in a water bath at 25℃for 5 min. It was found that other amino acids such as glutamate acid had some disturbance.%当有乙醛酸、琥珀酸存在时，γ-氨基丁酸（GABA）与溴甲酚绿发生专一的、特殊的显色反应。基于这一显色反应，建立了一种新的快速测定GABA含量的比色法。显色剂中溴甲酚绿、琥珀酸和乙醛酸溶液的适宜浓度分别为0.5、4.0 mg/mL和6.0 mg/mL。测定GABA含量的适宜条件为：4 mL样品溶液，加入2 mL显色剂，混合摇匀，在25℃下水浴5 min，于617 nm测定吸光值。其它氨基酸如谷氨酸对GABA测定有一定的影响。
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