A simplified method for the quantitation of short-chain fatty acids in human stool

• Published in: Analytical biochemistry Vol. 612; p. 114016
• Main Authors: Eberhart, B. Loye, Wilson, Annette S., O'Keefe, Stephen J.D., Ramaboli, Matsepo C., Nesengani, Lucky T.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.01.2021
• Subjects: Africa; Calibration; Fatty Acids, Volatile - analysis; Feces - chemistry; Flame Ionization - methods; Gas chromatography; Gas Chromatography-Mass Spectrometry - methods; Gut health; Human stool; Humans; Limit of Detection; Pilot Projects; Short-chain fatty acids; Solid Phase Extraction - methods; Solvents - chemistry; Africa; Gas chromatography; Short-chain fatty acids; Human stool; Gut health
• ISSN: 0003-2697; 1096-0309
• DOI: 10.1016/j.ab.2020.114016

A one-vial extraction method for the quantitation of short-chain fatty acids (SCFAs) in human stool was developed. Samples were extracted with an acidified aqueous internal standard solution, sodium sulfate, and diethyl ether, followed by analysis with GC-FID. Accuracy, in terms of relative recovery, was typically between 90 and 110% for most analytes; without internal standard, the accuracy was about 5–34%; the linear dynamic range (LDR) was 0.05–50 μmol per gram; the limit of detection (LOD) was less than or equal to 0.05 μmol per gram; and the (lower) limit of quantitation (LOQ) was 1 μmol per gram. The method is suitable for quantitating acetic acid, propanoic acid, isobutyric acid, butyric acid, isovaleric acid, valeric acid, isohexanoic acid, hexanoic acid, and heptanoic acid. It is not suitable for the quantitation of formic acid. Application to human biological research was tested by the measurement of SCFA in heathy humans. This confirmed that the method performed adequately, and even better than expected, with values up to 150 μmol per gram. [Display omitted] •This method uses a one- vial approach for quantitation of short-chain fatty acids in human stool.•GC run time is 21.5 min.•Extracts do not foul the injection port or the syringe.