A protocol for the extraction, identification, and quantification of short-chain fatty acids (SCFAs) in silages using Reverse Phase – High Performance Liquid Chromatography with Diode Array Detector (RP-HPLC-DAD)

Abstract

Short-chain fatty acid profile (SCFAs) in silage provides significant information regarding its fermentative patter in the rumen. Thus, we developed a protocol to extract, identify, and quantify the SCFAs of silages. The proposed method was tested with satisfactory results in corn silages. Despite literature findings suggest that the most common instrumental method for determining SCFAs is the gas chromatography technique, the liquid chromatography technique using both C18 column and ion-exchange columns can be proposed as analytical technique for SCFAs determination as well. The use of the C18 column in HPLC-DAD has a particular limitation because it does not allow efficient separation of butyric and iso-butyric acids. However, considering that the concentration of iso-butyric acid in silages is significantly lower than that of butyric acid, a good estimation of butyric acid can be obtained.