Department of Agricultural, Food and Nutritional Sciences, University of Alberta, Edmonton, Canada T6G 2P5.
J Chromatogr B Analyt Technol Biomed Life Sci. 2012 Dec 12;911:170-9. doi: 10.1016/j.jchromb.2012.10.038. Epub 2012 Nov 3.
A hydrophilic interaction liquid chromatography-tandem mass spectrometry (HILIC LC-MS/MS) method was developed and validated to simultaneously quantify six aqueous choline-related compounds and eight major phospholipids classes in a single run. HILIC chromatography was coupled to positive ion electrospray mass spectrometry. A combination of multiple scan modes including precursor ion scan, neutral loss scan and multiple reaction monitoring was optimized for the determination of each compound or class in a single LC/MS run. This work developed a simplified extraction scheme in which both free choline and related compounds along with phospholipids were extracted into a homogenized phase using chloroform/methanol/water (1:2:0.8) and diluted into methanol for the analysis of target compounds in a variety of sample matrices. The analyte recoveries were evaluated by spiking tissues and food samples with two isotope-labeled internal standards, PC-d(3) and Cho-d(3). Recoveries of between 90% and 115% were obtained by spiking a range of sample matrices with authentic standards containing all 14 of the target analytes. The precision of the analysis ranged from 1.6% to 13%. Accuracy and precision was comparable to that obtained by quantification of selected phospholipid classes using (31)P NMR. A variety of sample matrices including egg yolks, human diets and animal tissues were analyzed using the validated method. The measurements of total choline in selected foods were found to be in good agreement with values obtained from the USDA choline database.
建立并验证了亲水作用色谱-串联质谱（HILIC LC-MS/MS）法，可在单次运行中同时定量分析六种水合胆碱相关化合物和八种主要磷脂类别。采用正离子电喷雾质谱法进行 HILIC 色谱分析。优化了多种扫描模式的组合，包括前体离子扫描、中性丢失扫描和多重反应监测，以在单次 LC/MS 运行中确定每种化合物或类别的含量。本研究开发了一种简化的提取方案，其中游离胆碱和相关化合物以及磷脂均使用氯仿/甲醇/水（1:2:0.8）提取到均质相中，并稀释到甲醇中，以分析各种样品基质中的目标化合物。通过用两种同位素标记的内标物 PC-d(3)和 Cho-d(3)对组织和食品样品进行加标，评估了分析物的回收率。通过用含有所有 14 种目标分析物的真实标准品对一系列样品基质进行加标，回收率在 90%到 115%之间。分析的精密度范围为 1.6%到 13%。准确度和精密度与使用 (31)P NMR 定量分析部分磷脂类别的结果相当。使用经过验证的方法分析了各种样品基质，包括蛋黄、人类饮食和动物组织。发现选定食品中总胆碱的测量值与美国农业部胆碱数据库中的值吻合良好。
