Determination of volatile carboxylic acids (C1–C5i) and lactic acid in aqueous acid extracts of silage by high performance liquid chromatography

A simple isocratic h.p.l.c. technique was developed for the simultaneous quantitative analysis of lactic, formic, acetic, propionic, isobutyric, n-butyric and isovaleric acids in aqueous acid extracts of silage. An Aminex HPX-87H strong cation exchange resin column at 41°C, 0.0025M H₂SO₄ mobile phase and ultraviolet detector at 210 nm were utilised. Estimated recoveries of acids added to silage ranged from 98.2 to 103.5%.