超高效液相色谱-串联质谱-同位素标记-酸水解法同时测定婴配奶粉中胆碱和左旋肉碱  

Simultaneous determination of choline and L-carnitine in infant formula milk powder by ultra-performance liquid chromatography-tandem mass spectrometry-isotope labeling-acid hydrolysis

作　　者：詹胜群 葛城 刘金梅 丁玉珍 周荣杰 刘钢 张浩 周钧 ZHAN Shengqun;GE Cheng;LIU Jinmei;DING Yuzhen;ZHOU Rongjie;LIU Gang;ZHANG Hao;ZHOU Jun(Ausnutria Dairy(China)Co.Ltd.,Changsha 410200,China)

机构地区：[1]澳优乳业(中国)有限公司,湖南长沙410200

出　　处：《食品与发酵工业》2023年第24期302-311,共10页Food and Fermentation Industries

摘　　要：该研究建立超高效液相色谱-串联质谱法(ultra-high performance liquid chromatography-tandem mass spectrometry,UPLC-MS/MS)同时测定婴配奶粉中胆碱和左旋肉碱。样品经盐酸水解提取,通过调节pH、过滤膜等过程进行除杂并用乙腈稀释样液,以乙腈和10 mmol/L甲酸铵水溶液[甲酸调pH值至(5.0±0.1)]为流动相,采用酰胺柱进行梯度洗脱,多反应监测模式测定,内标法定量,通过提取后添加法评估基质效应。结果表明,胆碱和左旋肉碱的方法检出限分别为1、0.1 mg/kg,定量限为3、0.3 mg/kg;线性范围为0.8~200 ng/mL;样品加标回收率均为95%~105%,质控样结果均在特性值范围内;胆碱、左旋肉碱的仪器精密度分别为1.77%、4.36%,方法精密度分别为2.37%、2.71%;基质效应考察表明左旋肉碱无基质效应,胆碱则存在统计学上极显著的基质抑制(P<0.01),故需采用内标校正。该方法限值低、前处理简单、准确性高,适用于婴配奶粉中胆碱和左旋肉碱的同时测定。An ultra-high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS)method for the simultaneous determination of choline and L-carnitine in infant formula was established.The samples were extracted by hydrochloric acid hydrolysis,and impurity was removed by adjusting pH,then diluted with acetonitrile.In this method,the amide column was used,while acetonitrile and 10 mmol/L ammonium formate aqueous solution[formic acid pH adjusted to(5.0±0.1)]were the mobile phases,and the procedure of elution was gradient elution.The determination mode was MRM mode,quantified by the internal standard.In addition,the matrix effect was evaluated by the addition method after extraction.Results showed that the detection limits of choline and L-carnitine were 1 mg/kg and 0.1 mg/kg,respectively,and the quantitative limits were 3 mg/kg and 0.3 mg/kg.The linear ranged from 0.8 ng/mL to 200 ng/mL,the spike recovery ranged from 95%to 105%,and the results of the quality control samples were also well,in the characteristic value range.The precision of choline and L-carnitine were 1.77%and 4.36%for the instrument,and 2.37%and 2.71%for the method,respectively.The matrix effect investigation showed that L-carnitine had no matrix effect,while choline had a very significant matrix inhibition(P<0.01),so an internal standard correction was required.This method had low limits,simple pretreatment,and high accuracy,and it was suitable for the simultaneous determination of choline and L-carnitine in infant formula.

关 键 词：婴配奶粉 同位素标记 酸水解法 超高效液相色谱-串联质谱 胆碱 左旋肉碱 

分 类 号：O657.63[理学—分析化学] TS252.51[理学—化学]