ANALYSIS OF SOME ORGANIC ACIDS BY GAS–LIQUID CHROMATOGRAPHY

Abstract

Reoplex 400 coated Chromosorb W (10% w/w on Chromosorb W, 60–80 mesh) columns (15 inches × [Formula: see text] inch) were used with an Aerograph A-90-P2 gas chromatograph. Complete separations and symmetrical peaks of the methyl esters of lactic, glycollic, oxalic, malonk, succinic, malic, aconitic, tartaric, citric, isocitric, and fumaric acids and isocitric acid lactone were obtained by programming the temperature at 4 °C/minute from 55 °C to 175 °C. Single acids could easily be assayed at an isothermal temperature. A linear relationship was obtained between the areas recorded and the quantities of acid injected. There was no consistent relationship between molecular species and response, so that the instrument was calibrated for each individual acid. The analyses of some plant materials for organic acids are presented.