关键词: 离子色谱, 异麦芽酮糖醇, 糖醇, 食品

Abstract: In recent years, sugar alcohols have gradually been used as substitutes for sugar in foods, and their consumption is increasing daily. Hence, the determination of sugar alcohols has attracted considerable attention. However, the lack of accurate quantitative method has posed certain challenges for market regulation. Therefore, it is necessary to establish a suitable analytical method for sugar alcohols. In this study, ion chromatography was used to determine seven sugar alcohols （isomalt, erythritol, xylitol, sorbitol, mannitol, lactitol, and maltitol） in foods. Analysis was carried out on a Dionex CarboPac^TM MA1 chromatographic column （250 mm×4 mm,7.5 μm）, with a column temperature of 25 ℃ and an injection volume of 10 μL. A 200 mmol/L NaOH solution was used for elution at a flow rate of 0.4 mL/min. Sharp and symmetric chromatographic peaks were obtained under these conditions. The resolutions between isomalt and the other six sugar alcohols and sugars were greater than 1.5. The sample was extracted with 50 mL of water using ultrasound for 20 min, purified with 1 mL of acetic acid solution, and the supernatant was then diluted to one-tenth of its original concentration. The diluted solution was passed through a 0.22 μm filter membrane, and the filtrate was analyzed by ion chromatography. Under these conditions, seven sugar alcohols including isomalt were quantitatively analyzed using the external standard method and showed good linearity within the range of 2.5-80 mg/L, with coefficients of determination （R²） greater than 0.999. The limits of detection of this method were 0.01-0.05 g/100 g, and the limits of quantification were 0.03-0.15 g/100 g. In addition, when blank food samples were spiked with seven sugar alcohols at three levels, the average recoveries were 97%-105%, with relative standard deviations （RSDs） of 0.7%-4.1% （n=6）. An RSD of <5% indicated that the method had good precision. Interference experiments were performed to determine whether the sugars and sugar alcohols commonly found in food affected the targets. Moreover, the method was applied in the 2024 DRRR-Proficiency Testing, and the results were satisfactory. The method established in this study was used to analyze the content of the seven sugar alcohols in the food samples and isomalt. The experimental results showed that the actual content of sugar alcohols in the food samples was generally consistent with the labeled values. However, some isomalt did not meet their claimed specifications. The proposed method features simple operation, high sensitivity, and good reproducibility, thus it meets the requirements for the detection of seven sugar alcohols in foods and raw materials. It also provides technical support for the detection of sugar alcohols in foods.

Key words: ion chromatography （IC）, isomalt, sugar alcohol, food