高效毛细管电泳 间接紫外吸收检测法测定食品中的氨基酸

研究了鸟氨酸、脯氨酸和谷氨酰胺的高效毛细管电泳 间接紫外吸收检测的特征。以5　mmol/L 对氨基苯磺酸钠 10 mmol/L KH2PO4(pH 11.5)为运行缓冲液,在分离电压12 kV下,于11 min实现了上述3种氨基酸的基线分离,迁移时间和峰高的相对标准偏差分别小于0.72%和2.0%,检测限分别为6.78，8.71，7.86 mg/L。应用该法测定食品中的氨基酸及各氨基酸在样品中的加标回收率,3种氨基酸的加标回收率为96.8%~104%。

Simultaneous Determination of Amino Acids in Food by Capillary Electrophoresis with Indirect Ultraviolet Detection

The characteristic of capillary electrophoresis (CE) with indirect ultraviolet (UV) detection of L-ornithine (Orn), L-proline (Pro) and L-glutamine (Gln) was investigated. A suitable electrolyte consists of 5 mmol/L sodium p-aminobenzene sulfonic acid-10mmol/L KH_2PO_4 ( pH 11.5) with UV detection at 254 nm. The applied voltage was set at 12 kV. The three amino acids were completely separated and detected by the method in 11 min. The relative standard deviations (RSD) of the method were better than 0.72% for migration time and 2.0% for peak height. The detection limits of Orn, Pro and Gln were 6.78, 8.71 and 7.86 mg/L, respcetively. The proposed method was successfully applied to the determination of amino acids in foods (Haitian soybean sauce, Tsingtao beer and amino acids tonic) and the recoveries were in the range of 96.8%-104%.