Determination of Common Carbohydrate Compounds in Beverages by Domestic Ion Chromatography with Self-Designed Pulsed Amperometric Detector

Glucose, fructose, lactose, sucrose and maltose commonly found in beverages were determined by domestic ion chromatography with self-designed pulsed amperometric detector. As shown by the results, linear relationship between values of the corresponding peak area and mass concentration of 5 carbohydrate compounds were found in the range of 0.2-5.0 mg·L^-1, with detection limits (3S/N) of 3.420, 6.759, 10.12, 20.43, 31.37 μg·L^-1, respectively. Test for recovery was made by the standard addition method, giving the results in the range of 94.1%-114%, with RSDs (n=5) of the determined values less than 5.0%, indicating that this method could meet the requirements of relevant testing standards. To investigate the accuracy of domestic instrument analysis and evaluate the performance of main modules, it was compared with Thermo ICS 5000+ion chromatograph amperometric detection system and Dionex Ultimate 3000 liquid chromatograph differential detector system, and it was shown that the analysis results were consistent, but the detection limit of domestic ion chromatography system with self-designed pulsed amperometric detector was 3 to 4 times higher than the imported instrument. The performance of each module and machine of domestic ion chromatography instrument was stable, and it could meet the requirements for the determination of conventional carbohydrate compounds.