Abstract: A method for the simultaneous determination of water-soluble sugars in fresh jujubes by high performance liquid chromatography with evaporative light-scattering detector (HPLC-ELSD) was established. The carbohydrates were separated on a chromatographic column of Waters XBridgeTM Amide (4.6 mm × 250 mm, 5 μm) with a mobile phase consisting of A (0.2% triethylamine aqueous solution) and B (0.2% triethylamine in acetonitrile) (A:B = 24:76, V/V). The column temperature was 30 ℃ and the atomization temperature was 60 ℃. The drift tube temperature of ELSD was 60 ℃. Nitrogen was used as the carried gas with a flow rate of 1.6 L/min and a gain value of 1.0. These experimental conditions allowed good separation of water-soluble sugars, such as rhamnose, arabinose, glucose, mannose, glucose, sucrose, maltose and lactose with a resolution of 1.5 or above. Good linearity was observed for the analytes in the concentration range of 0.099–1.040 ng/μL. The recoveries of spiked real samples ranged from 93.1% to 111.2%, with relative standard deviation (RSD) values below 5%. The limits of detection (RSN = 3) were in the range of 0.008–0.03 ng/μL. This method had a lot of advantages including simple operation, effective separation and time saving, and could be used to determine water-soluble sugars in fresh jujube. Compared with the traditional spectrophotometric method, HPLC-ELSD was more sensitive and accurate making it more suitable for quality identification of fresh jujube.

Key words: jujube fruit, high performance liquid chromatography with evaporative light-scattering detector (HPLC-ELSD), water-soluble sugar, monosaccharide, oligosaccharide