A new Method to determine Short Chain Fatty Acids in Rat Feces by SPME-GC-FID
Dennis Fiorini1, Deborah Pacetti2, Paride Logiodice1, Maria Chiara Boarelli1, Serena Gabrielli,1 Enrico Marcantoni1, Roberto Ballini1 
1School of Science and Technology, Chemistry Division, University of Camerino (Camerino, Italy), 2Department of Agricultural, Food, and Environmental Sciences,  Università Politecnica delle Marche (Ancona, Italy)

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
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