Cuevas-Tena María, Alegría Amparo, Lagarda María Jesús
Nutrition and Food Chemistry Area, Faculty of Pharmacy, University of Valencia, Avda. Vicente Andrés Estellés s/n, Burjassot, Valencia, 46100, Spain.
Lipids. 2017 Oct;52(10):871-884. doi: 10.1007/s11745-017-4286-6. Epub 2017 Sep 6.
The aim of this study was to develop a method for neutral fecal sterols determination in subjects receiving a normal diet with or without a plant sterols-enriched beverage using gas chromatography-mass spectrometry (GC/MS). Sample preparation conditions (homogenization of lyophilized feces with water) were evaluated. Sterol determination required direct hot saponification, unsaponifiable extraction with hexane, and the formation of trimethylsilyl (TMS) ether derivatives. The method allows the quantification of cholesterol, plant sterols and their metabolites (coprostanol, coprostanone, cholestanol, cholestanone, methylcoprostanol, methylcoprostanone, ethylcoprostenol, stigmastenol, ethylcoprostanol and ethylcoprostanone). Good linearity was obtained (r > 0.96) and interference was only observed for coprostanone, where the standard addition method proved necessary for quantification. The limits of detection (LOD) ranged from 0.10 to 3.88 µg/g dry feces and the limits of quantitation (LOQ) from 0.34 to 12.94 µg/g dry feces. Intra- and inter-assay precision (RSD %) were 0.9-9.2 and 2.1-11.3, respectively. Accuracy, expressed as percentage recovery (80-119%) was obtained for all determined sterols.
本研究的目的是开发一种使用气相色谱 - 质谱联用仪（GC/MS）测定正常饮食受试者（无论是否饮用富含植物甾醇的饮料）中性粪便甾醇的方法。评估了样品制备条件（冻干粪便与水的匀浆）。甾醇测定需要直接热皂化、用己烷提取不皂化物以及形成三甲基硅烷基（TMS）醚衍生物。该方法能够对胆固醇、植物甾醇及其代谢产物（粪甾烷醇、粪甾烷酮、胆甾烷醇、胆甾烷酮、甲基粪甾烷醇、甲基粪甾烷酮、乙基粪甾烯醇、豆甾烯醇、乙基粪甾烷醇和乙基粪甾烷酮）进行定量。获得了良好的线性关系（r > 0.96），仅在粪甾烷酮中观察到干扰，在此情况下，标准加入法被证明是定量所必需的。检测限（LOD）范围为0.10至3.88 μg/g干粪便，定量限（LOQ）范围为0.34至12.94 μg/g干粪便。批内和批间精密度（RSD%）分别为0.9 - 9.2和2.1 - 11.3。所有测定的甾醇的准确度以回收率百分比（80 - 119%）表示。
