A new method to determine short chain fatty acids in rat feces by SPME-GC-FID

The analysis of free fatty acids plays an important role in several fields; in fact these compounds are in relationship with the quality of several foods (1,2), with the health state of animals and humans (3) and their amount and composition are meaningful in a number of other matrices. The quantity of short chain fatty acids (SCFAs) in the intestinal content is important, since they are fermentation products of dietary fiber and they have been associated with reduced risk of some diseases, including the irritable bowel syndrome, inflammatory bowel disease, cardiovascular disease and cancer (3). Thus, in the presented study, headspace solid-phase microextraction gaschromatography with flame ionization detection is exploited for developing and validating a method to quantify SCFAs (acetic, propionic, isobutyric, butyric, isovaleric, valeric and caproic acids) in rat fecal samples. Fiber coating, pH of the sample, conditioning and extraction time, salting out effect, linearity, limit of detection and quantification, repeatability and recovery are under evaluation and preliminary results will be presented. References 1) González-Córdova AF, Vallejo-Cordoba B (2003). Detection and Prediction of Hydrolytic Rancidity in Milk by Multiple Regression Analysis of Short-Chain Free Fatty Acids Determined by Solid Phase Microextraction Gas Chromatography and Quantitative Flavor Intensity Assessment. J Agric Food Chem 51:7127-7131 2) Olivero SJP, Trujillo JPP (2011). A new method for the determination of short chain fatty acids from the aliphatic series in wines by headspace solid phase microextraction-gas chromatography-ion trap mass spectrometry. Anal Chim Acta 696:59-66 3) Wong JMW, de Souza R, Kendall WC, Emam A, Jenkins DJA (2006). Colonic Health: Fermentation and Short Chain Fatty Acids. J Clin Gastroenterol 40:235-243