Optimization of the ion-exchange analysis of organic acids from fermentation

A method using high performance liquid chromatography (HPLC) is described to quantify 13 organic acids commonly found as products of fermentation. The isocratic method uses a 30 cm sulfonated polystyrene divinyl benzene column with ultraviolet detection at 210 nm to quantify acetic, butyric, citric, formic, fumaric, isobutyric, alpha-ketoglutaric, lactic, malic, propionic, pyruvic, succinic, and uric acids. Since all 13 acids are rarely found together in a single sample from a fermentation medium, a method is described to select the optimal temperature and eluent concentration for a given subset of these organic acids. This simple chromatographic optimization is applied to select conditions for the quantification of fermentation products of two anaerobic microorganisms, Fibrobacter succinogenes and Clostridium coccoides.