超高效液相色谱-串联质谱法同时测定人乳中的胆碱、L-肉碱、乙酰基-L-肉碱和牛磺酸

摘要

目的：建立一种简单、快速、灵敏的可以同时测定人乳中胆碱、L-肉碱、乙酰基-L-肉碱和牛磺酸的超高效液相色谱-串联质谱法。方法样品经甲醇沉淀蛋白、乙醚去除非极性杂质, UPLC BEH Amide色谱柱分离后采用保留时间和多反应离子检测(MRM)定性、定量,同位素内标校正。结果牛磺酸的定量下限(LOQ)为0.02 mg/100 g,胆碱、L-肉碱和乙酰基-L-肉碱的LOQ均为0.003 mg/100 g。标准加入法测定所有被测物的高、中、低三个浓度加标水平的回收率在84.8%~90.3%之间,相对标准偏差(RSD)在1.7%~5.3%之间。4种被测物在各自浓度范围内线性良好, R2均大于0.999。结论本文建立了同时测定人乳中胆碱、L-肉碱、乙酰基-L-肉碱和牛磺酸的超高效液相色谱-串联质谱法。方法前处理简单、快速,样品需要量少；采用质谱检测器同位素内标一对一校正定量,检测结果准确、灵敏。方法可以为人乳中相关营养素含量的调查、研究和为配方奶粉人乳化提供技术支持。%Objective To establish a rapid and sensitive method which can determine choline, L-carnitine, acetyl-L-carnitine and taurine in human milk by ultra-performance liquid-chromatography tandem mass spec-trometry (UPLC-MS/MS). Methods The non-polar substances and protein were removed from samples by ether and methanol respectively. The sample extracts were separated by a UPLC BEH Amide column. The de-tection was performed with mass spectrometry under multiple reaction monitoring (MRM) mode with stable isotopedilution method. Results LOQs of choline, L-carnitine, acetyl-L-carnitine and taurine were between 0.003 mg/100 g and 0.02 mg/100 g. The spiked recoveries were 84.8%~90.3%. The precision RSD were below 5.3%. The lineal range was with high correlation coefficients (R2>0.999). Conclusion A simultaneous quanti-fication of choline, L-carnitine, acetyl-L-carnitine and taurine in human milk was developed by using a UHPLC-MS/MS method. The sample preparation was simple, rapid and required small volume of samples. Four stable isotope standards which provide high precision and accurate were used for each analyte. The de-veloped method was suitable for the study of four kinds of analytes which were concentrated in human milk and provided the technical support for the infant formula.