Determination of sugars and sugar alcohols in infant formula by high performance liquid chromatography with evaporative light-scattering detector

A method was established for the simultaneous determination of five sugars (fructose, glucose, sucrose, lactose, maltose) and five sugar alcohols (erythritol, xylitol, sorbitol, mannitol, maltitol) in infant formula by high performance liquid chromatography-evaporative light scattering detector. After the samples were extracted with acetonitrile-water solution, precipitated by acetic acid, and purified with solid phase extraction cartridge, ALLChrom Rocksil Carbohydrate ES column was adopted for separation, and isocratic elution was conducted at the flow rate of 1.0 mL/min with acetonitrile-0.04 % ammonia solution as the mobile phase. The analytes were detected by an evaporative light-scattering detector, and quantified by external standard method. The linear ranges of the 10 components were 0.04-4.0 g/L with the correlation coefficients greater than 0.999, and the limits of quantification (S/N = 10) of the method were 0.08-0.4 g/100 g. The relative standard deviation of the lactose parallel samples reached 1.29 %, and the recoveries of the other 9 components ranged from 80.4 % to 99.4 % with the relative standard deviation of 2.8 %-7.1 %. The method performs well in sensitivity and separation, which is suitable for the simultaneous quantitative determination of sugars and sugar alcohols in infant formula.