Abstract:A method for the determination of soluble sugars in sweetpotato by ion chromatography and pulsed amperometric detector (IC-PAD) was established, and it can detect 10 kinds of soluble sugars (glucose, fructose, galactose, mannose, rhamnose, arabinose, sucrose, maltose, raffinose and stachyose) in sweetpotato at the same time. The sweetpotato powder samples were extracted by low temperature ultrasonic oscillation with 80% ethanol aqueous solution and membrane filtration. The analytical column was Carbo Pac PA20 Analytical Column (3 mm×150 mm), the column CarboPac PA20 Guard Column (3 mm×50 mm) was used as the protective column. The mobile phase was NaOH and CH3COONa, gradient elution procedure was used for separation and pulse integral amperometric for detection. The exchange column kept at 30 ℃, the injection volume 10 μL, the eluates were detected with an Au working electrode. The linear range of six monosaccharides was 0.02-10 mg/L, the linear range of the other four sugars was 0.02-20 mg/L. The recoveries of these ten sugars from spiked samples was 94.5%-106.5%, relative standard deviation was 0.57%-1.89%. This method has the advantages of wide linear range, simple operation, fast analysis speed, high sensitivity and reproducibility. It can be used for the simultaneous determination of various soluble sugars in sweet potato extract. The determination results of actual samples by this method show that different drying methods have different effects on the soluble sugar content of sweet potato, compared with the freeze drying method, the hot air drying increases the soluble sugar content in sweetpotato and promotes the transformation of other sugars to produce raffinose and stachyose.