UPLC-MS/MS法与分光光度法测定乳及乳制品中左旋肉碱的比较  

Comparison of ultra-high performance liquid chromatography-electrospray ionization tandem mass spectrometry and spectrophotometry in the detemination of L-carnitinein in milk and dairy products

作　　者：单艺[1] 王象欣[1] 赵秋莲[1] 陈美君[1] 梁杰[1] 姜毓君[1] 

机构地区：[1]东北农业大学黑龙江省乳品工业技术开发中心,黑龙江哈尔滨150028

出　　处：《食品与发酵工业》2014年第6期152-158,共7页Food and Fermentation Industries

基　　金：国家科技支撑计划(2012BAK17B04和2013BAD18B11)

摘　　要：文中建立了超高效液相色谱-质谱联用仪（UPLC-MS/MS）和分光光度计测定乳及乳制品中L-肉碱的方法。超高压液相色谱-质谱联用法采用C8（3.5μm,50 mm×2.1 mm）色谱柱,0.1%七氟丁酸/水溶液和甲醇作为流动相分离样品,L-肉碱-（甲基-d3）内标物质用以消除信号抑制和基质干扰,质谱采用ESI＋电离模式、多离子反应监测（MRM）方式进行检测。分光光度法采用高氯酸沉淀蛋白质,碱皂化使溶液中结合态的左旋肉碱游离出来,通过酶促反应,使用分光光度计间接测定左旋肉碱。结果表明：分光光度法的检出限为2.0 mg/100 g,回收率在96.2%-104.7%,相对标准偏差RSD在1.34%-3.69%。UPLC-MS/MS法的检出限为2 ng/100 g,回收率在97.8%-109%,相对标准偏差RSD为1.77%-5.65%。以上2种方法均适用于乳及乳制品中L-肉碱的检测,且测定结果无显著性差异。UPLC-MS/MS法具有操作简便、快速、高效、可控性强等特点,更适用于大量样品的集中快速检测。Ultra-High Performance Liquid chromatography-electrospray ionization tandem mass spectrometry and- spectrophotometry was developed for the determination of L-carnitinein milk and dairy products. A C8 column （3.5μm,50 × 2. 1 mm） was used for liquid chromatography, with mobile phases consisting of 0. 1% heptafluorobutyric acid in water and methanol. L-Carnitine-d3 was a stable isotope internal standard （ISTD） , which helped to normalize signal suppression and matrix effects. Spectrophotometry used perchloric acid to precipitate protein, alkaline saponifi- cation was used to separate free combined L-earnitine. After enzymatic reaction, spectrophotometer can detect the content of L-carnitine. The results of spectrophotometry showed that the limit of detection was 2.0 mg/100 g, the re- covery was 96.2% -104.7%, relative standard deviation （RSD） wasl. 34% -3.69%. The results of UPLC-MS/ MS showed that the limit of detection was 2 ng/100 g, recovery was 97.8% - 109% , relative standard deviation （RSD） wasl. 77% - 5.65%. The two methods are suitable for analysis of L- carnitine in milk and dairy products, and the results had no significant difference. UPLC/MS/MS method was simple operation, rapid, efficient, controlla- ble. It is suit for rapid, large amount of samples detection.

关 键 词：L-肉碱 超高压液相色谱─质谱联用法 分光光度法 乳制品 

分 类 号：O657[理学—分析化学] TS252.7[理学—化学]