Abstract:Intestinal microbiota and its main metabolites, short-chain fatty acids (SCFAs), are considered to be important factors for intestinal environmental stability and metabolic diseases. Gas chromatography-mass spectrometry (GC-MS) is the most commonly used method for the analysis of short-chain fatty acids in biological samples. Trimethylsiliconyl (TMS) derivatization reagents N,O-bis (trimethylsiliconyl) -trifluoroacetamide (BSTFA) are commonly used to improve the sensitivity and accuracy of gas chromatography/mass spectrometry. We used BSTFA to analyze SCFAs in feces, cecum and colon contents by GC-MS. Selective ion monitoring mode was used for quantitative analysis of short-chain fatty acids with high sensitivity. At 37 °C, SCFAs derived from BSTFA showed good linearity (R2>0.998), recovery 86%-96% and precision RSD<4%. The results showed that GC-MS combined with BSTFA derivatization can be successfully applied to quantitative analysis of SCFAs in feces, and it is an accurate and universal method.