Modification of Determination of Organic Acids in Foods by High Performance Liquid Chromatography

Abstract

A liquid chromatographic method was established for the determination of citric, tartaric, gluconic, malic, succinic, lactic, fumaric, acetic, adipic and propionic acids in foods.A sample was homogenized in water. The homogenate was adjusted pH 9-10 then warmed for 15min at 80°C. After filtration, the extracted solution was poured onto a column of DEAE-Sephadex previously treated with 0.5N boric acid. The column was washed with water. The organic acids were eluted with 0.1% methyl red in ethanol-0.1N hydrochloric acid (0.1:500). The red portion of eluate was collected. The eluate was concentrated after neutralization with 10% sodium carbonate solution, if necessary. The organic acids in the eluate were separated on a Shodex lonpak KC811 column at 55°C.Recoveries were 87.5-102% and coefficients of variation were 1.74-4.73%. This method was applied to determination of the organic acids in foods.