Gas Chromatography/Electron-Capture Negative Ion Mass Spectrometry for the Quantitative Determination of 2- and 3-Hydroxy Fatty Acids in Bovine Milk Fat
作者:Ramona Jenske、Walter Vetter
DOI:10.1021/jf800647w
日期:2008.7.1
2-OH-18:1(9 c) methyl ester as well as the ethyl ester of 3-PFBO-O-12:0 (ISTD-2) was synthesized. ISTD-1 served as a recovery standard whereas ISTD-2 was used for GC/MS measurements. The whole-sample cleanup consisted of accelerated solvent extraction of dry bovine milk, addition of ISTD 1, saponification, conversion of fatty acids into methyl esters by use of boron trifluoride, separation of the methyl
2-和3-羟基脂肪酸(2-和3-OH-FAs)是鞘脂和细菌中报告的生物活性物质。人们对它们在食物中的存在知之甚少。因此,开发了一种适用于牛乳脂肪中痕量OH-FAs测定的方法。将OH-FAs(和样品中的常规脂肪酸)转化为甲酯,然后用五氟苯甲酰氯(PFBO)将羟基衍生化,得到PFBO-O-FA甲酯。这些具有强电子亲和力的衍生物是通过在所选离子监测模式下使用电子捕获负离子通过气相色谱与质谱联用确定的(GC / ECNI-MS-SIM)。事实证明,该方法对PFBO-O-FA甲酯具有高度的敏感性和选择性。为了分析样品,使用了两个内标。为此,9,来自2-OH-18:1(9 c)甲酯的10-dideutero-2-OH-18:0甲酯(ISTD-1)以及3-PFBO-O-12:0的乙酯-2)被合成。ISTD-1用作回收标准,而ISTD-2用于GC / MS测量。整个样品净化包括加速溶剂萃取干牛乳,添加ISTD