Quantitative Determination of Short Chain Fatty Acids in Synthetic Feces Using Gas Chromatography with Flame Ionization Detection or Mass Spectrometry

Short chain fatty acids (SCFAs) are produced in the gut as a result of microbial action on ingested dietary fiber and have been associated with several health benefits. Herein an undergraduate student experiment that uses gas chromatography equipped with either a flame ionization detector or mass spectrometer for the analysis and quantitation of SCFAs in synthetic fecal material is described. The experiment provides students with valuable sample preparation and instrument operation skills and provides an opportunity for students to perform quantitative analysis using the method of internal standards. Subsequently, the experiment provides an opportunity for students to consolidate their learning of the key theoretical concepts including chromatographic separation by gas chromatography, and methods for confirming analyte identity using each detector type. Due to recent global interest in gut health, the experiment is topical and of interest to students. The experiment is designed for upper-division undergraduate analytical chemistry students.