Organic acids analysis in "Brandy de Jerez" ion-exclusion chromatography, "post-column" buffering and conductimetric detection

A rapid ion-exclusion chromatographic method with conductimetric detection for the determination of the main carboxylic acids (citric, tartaric, malic, fumaric, succinic, lactic, formic and acetic acids) in "Brandy de Jerez" is described. In order to increase the detection sensitivity, a pH 6.5 buffer Is added to the column effluent to ensure that the analytes are ionized. The linearity, sensitivity and repeatibility were evaluated for each acid. Detection limits ranging from 43.054 mg/L (acetic acid) to 0.732 mg/L (succinic acid) were obtained. The ion exclusion with "post-column" buffering and conductimetric detection permits the analysis of brandies without interferences from sugars and phenolic compounds.