毛细管电泳-间接紫外检测法分离和测定食品中的有机酸

有机酸毛细管电泳（CE）分析是90年代初首先被报道的1]，近年来有了较大的发展2]．采用CE法可进行不同基质样品如食品、饮料、尿液等样品中多种有机酸的同时分析1，3，4]．该法采用CE的阴离子分离模式，在电解质溶液中加入电渗流改性剂，使电渗流方向逆向，从而与阴离子的电泳方向一致，以缩短分析时间．常见有机酸在200um以上大多无紫外吸收，一般采用间接紫外检测方法1，3]，也可采用低波长紫外检测4]．低分子量阴离子的CE研究报道不多5，6]，有机酸的CE分离系统研究尚未见报道．本文系统地研究了毛细管电泳-间接紫外检测法分析…

Separation and Determination of Organic Acids in Foods by Capillary Electrophoresis with indirect UV Detection

Capillary electrophoresis(CE) with indirect UV detection method for theseparation and determination of several organic acids commonly found in foods were developed.Effects of PH, background electrolytes and electroosmotic flow modifiers on separation wereinvestigated. The carrier electrolyte PH played an important role in the separation of organicacids. All analytes could be separated in one run by performing CE with 5. 0 mmol/Lphthalate-3. 0 mmol/L dodecyl trimethyl ammonium chloride (DTAC) at pH=7. 0 within 6 min.The reproducibllity(RSD) of the method is less than 0. 17% for migration time and 4. 2% forthe peak area (n=8). Linearity was observed more than one order between 1 and 80 mg/L.The detection limits are obtained from 0. 5 to 5. 0 mg/L. A variety of matrix samples such aswine, juices and soy sauce were determined by the method. The recoveries were in the rangeof 95 % ~102 %.