氨酪酸与邻硝基酚的荷移反应研究

Study on Charge Transfer Reaction of γ-Aminobutyric Acid with o-Nitrophenol

采用分光光度法研究了氨酪酸与邻硝基酚的荷移反应。由实验得知,用二甲亚砜做溶剂,室温下反应10 min后,可生成稳定的1∶1型的黄色络合物,其最大吸收波长λmax=446 nm,氨酪酸的浓度在2～16μg/mL的范围内遵循比尔定律,表观摩尔吸光系数ε=3.7×103L·mol-1·cm-1,桑德尔灵敏度S=0.028μg·cm-2。用拟定的方法测定氨酪酸片的含量,回收率在97.0%～102.7%范围内,相对标准偏差不大于2.1%。

A simple,quick and sensitive spectrophotometric method has been established for the determination of γ-aminobutyric acid based on charge transfer（CT） reaction with o-nitrophenol in dimethyl sulfoxide solvent at room temperature.The composition of charge transfer complex of γ-aminobutyric acid with o-nitrophenol was found to be 1∶1 by Job＇s method.The apparent molar absorptivity of the complex was determined for 3.7×103 L·mol-1·cm-1,and the Sandell sensitivity was 0.028 μg·cm-2 at 446 nm.The calibration curve was linear in the concentration range of 2~16 μg/mL.This proposed method has been applied to the determination of γ-aminobutyric acid in tablets with satisfactory results.The recoveries were 97.0%~102.7% and RSDs were less than 2.1%.