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

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%.