Fermentation-derived short-chain fatty acids (SCFA)44SCFA: short-chain fatty acids. are potential mediators of the health benefits associated with dietary fiber intake. SCFA affect physiological processes locally in the gut and on distant organs via the systemic circulation. Since SCFA are used as energy source for colonocytes and substrate for the liver metabolism, their concentrations in the systemic circulation are low. Therefore, quantification of systemic SCFA requires sensitive analytical techniques. This article covers the optimization and validation of a gas chromatography-mass spectrometry method to measure systemic SCFA concentrations following derivatization with 2,4-difluoroaniline (DFA)55DFA: 2,4-difluoroaniline. and extraction in ethyl acetate. Sample preparation was optimized by varying the amount of DFA, coupling agent 1,3-dicyclohexylcarbodiimide, ethyl acetate and sodium bicarbonate, which is used to quench derivatization. In addition, evaporation of the samples using a vacuum concentrator resulted in less contamination, notably of acetate, compared to drying with N2 gas. The method showed excellent linearity with coefficient of variation (R2) > 0.99 and a good precision (relative standard deviation < 20 %) and accuracy. Finally, systemic concentrations of SCFA in human plasma samples could successfully be determined.

中文翻译：

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气相色谱-质谱法分析人血浆或血清中乙酸盐、丙酸盐和丁酸盐浓度的优化和验证


发酵衍生的短链脂肪酸（SCFA）44SCFA：短链脂肪酸。是与膳食纤维摄入相关的健康益处的潜在调节因素。 SCFA 影响肠道局部生理过程，并通过体循环影响远端器官。由于SCFA用作结肠细胞的能量来源和肝脏代谢的底物，因此它们在体循环中的浓度较低。因此，系统性 SCFA 的量化需要灵敏的分析技术。本文介绍了气相色谱-质谱法的优化和验证，用于测量 2,4-二氟苯胺 (DFA)55DFA：2,4-二氟苯胺衍生化后的全身 SCFA 浓度。并用乙酸乙酯萃取。通过改变 DFA、偶联剂 1,3-二环己基碳二亚胺、乙酸乙酯和用于猝灭衍生化的碳酸氢钠的量来优化样品制备。此外，与使用氮气干燥相比，使用真空浓缩器蒸发样品可减少污染，尤其是醋酸盐。该方法表现出优异的线性度，变异系数 (R2) > 0.99，以及良好的精密度（相对标准偏差 < 20 %）和准确度。最后，可以成功测定人血浆样本中 SCFA 的全身浓度。