Separation and identification of organic acids in root exudates of lupinus luteus by capillary zone electrophoresis.

Abstract

The separation and identification of a mixture of organic acids by capillary electrophoresis, with direct detection by UV absorption at a wavelength of 200 nm is reported. A solution containing the following organic acids was studied: oxalic, formic, fumaric, malic, succinic, citric, acetic and lactic acid. Separation was achieved using a fused-silica capillary filled with phosphate buffer (200 mM; pH 6) containing N-acetylN,N,N-trimethylammonium bromide (0.5 mM) as cationic surfactant, necessary to modify the electrosmotic flow. The composition of organic acids in exudates of Lupinus luteus was determined by this method.