Abstract: A simple and sensitive high performance liquid chromatography (HPLC) method was established for simultaneous determination of seven organic acids in order to investigate the effects of organic acid metabolism on the cottony softening and quality of wax apple during postharvest storage. An Atlanis T3 chromatographic column (4.6 mm × 250 mm, 5 μm) was used to separate the organic acids. The mobile phase was a mixture of 0.02 mol/L phosphate solution (pH 2.2) and methanol at a ?ow rate of 0.5 mL/min. The column temperature and UV detection wavelength were set as 25 ℃ and 213 nm, respectively. The seven organic acids were successfully separated and detected under the above experimental conditions. The method displayed a wide linear range with correlation coefficients all above 0.999 5. The limits of detection (LODs) were in the range of 0.001–0.014 mg/g and the limits of quantitation (LOQs) were in the range of 0.003–0.042 mg/g. The spiked recoveries ranged from 86.84% to 98.86%, with relative standard deviation (RSD) less than 5%. This method proved to be a suitable, efficient, quick, accurate and sensitive method for the determination of the seven organic acids in wax apple fruit. The measured contents of organic acids during storage were as follows: pyruvic acid 0.395–0.975 mg/g, malic acid 6.951–10.059 mg/g, ascorbic acid 0.013–0.172 mg/g, lactic acid 0.030–0.735 mg/g, acetic acid 0.263–0.702 mg/g, citric acid 1.658–5.370 mg/g, and fumaric acid 0.269–0.518 mg/g.

Key words: high performance liquid chromatography; wax apple; organic acids