[Simultaneous determination of twenty-one organic acids in food by ion chromatography with eluent autogeneration].

A novel ion chromatographic method was developed for the simultaneous determination of organic acids in food samples including quinic acid, acetic acid, pyruvic acid, ketosuccinic acid, mannitic acid, lactic acid, succinic acid, malic acid, tartaric acid, oxalic acid, fumaric acid, ascorbic acid, alpha-ketoglutaric acid, cinnamic acid, salicylic acid, citric acid, isocitric acid, ferulic acid, cis-aconitic acid, trans-aconitic acid, beta-coumaric acid. 5 - 34 mmol/L KOH produced by an EG40 eluent autogenerator could achieve a flat baseline and lower background conductance when performing gradient elution. The flow rate was 0.6 - 2.5 mL/min and the injection volume was 25 microL. The separation was performed on an IonPac AS11 column and detected by suppressed conductivity with self-regenerating suppressor mode. The samples were prepared through extraction, decoloration and filtration before analysis. Twenty-one organic acids showed good linear relationship between the mass concentration and the peak area in the measurement ranges. The correlation coefficients were above 0.999 and the detection limits were 0.011 - 0.188 mg/L, and the average recoveries were 91.5% - 101.8%. The method is simple and rapid with good accuracy and reproducibility, and has been applied to determine twenty-one organic acids in diversiform samples with satisfactory results.