Simultaneous Analysis for Carbohydrates in Drinks by High Performance Liquid Chromatography with Charged Aerosol Detector

Abstract

An HPLC method with a charged aerosol detector (CAD) was optimized and validated for the quantification of six carbohydrates (xylose, fructose, glucose, sucrose, lactose, maltose) and sugar alcohol (erythritol) in drinks. Chromatographic separation was achieved using gradient elution with a mixture of water-methanol (7 : 3) and acetonitril. Carbohydrates were cleaned up using a strong cation exchange cartridge (Bond Elut SCX, Varian). Although an interfering peak appeared without any clean up, it was confirmed that interfering substance had be removed by a treatment using this cartridge and its peak had disappeared. The determinations were performed in the linear range of 5 ∼ 10000 μg/mL for six carbohydrates and sugar alcohol, the correlation coefficients (R) were 0.998 ∼ 1.000, the relative standard deviations (RSDs) ranged over 0.4 ∼ 4.5% (spiked level at 500 μg/mL, n = 5), recoveries ranged between 84 ∼ 113% (spiked level at 500 μg/mL, n = 3), and the limits of quantification were 0.4 ∼ 19.3 μg/mL. In addition, we performed analysis of carbohydrates with CAD, an evaporative light scattering detector (ELSD) and a refractive index detector (RID) to compare and investigate the sensitivity and analysis precision in the each optimum condition. As for the CAD, high sensitivity and good analysis precision were provided. Because it is not necessary to optimize the conditions, CAD is the simplest and easiest device in these detectors. It became clear that CAD was the most suitable to perform correct quantitative analysis of carbohydrates in drinks.