Rapid Determinations of Saccharides in High-Energy Drinks by Short-Capillary Electrophoresis with Contactless Conductivity Detection
Abstract
The methodology for separations of saccharides in standard electrophoretic systems has been transferred to the short-capillary electrophoresis format. The laboratory-designed apparatus used employs a quartz capillary with an internal diameter of 10 mum, a total length of 10 cm and an effective length of 4 cm, in combination with contactless conductivity detection.
It has been applied to separations of neutral mono- and disaccharides. The saccharides are separated in the anionic form, in solutions of alkali hydroxides, namely, KOH, NaOH and LiOH.
The separation of a model mixture of five saccharides (sucrose, lactose, glucose, fructose and ribose) takes less than one minute, the LOD equaling 15, 35, 19, 17 and 24 mg L-1 and the LOQ equaling 52, 117, 63, 53 and 79 mg L-1 for sucrose, lactose, glucose, fructose and ribose, respectively. The technique developed has been used to determine sucrose, glucose and fructose in high-energy drinks.
The separation is finished within less than 50 s, the saccharide contents determined are identical with the declared values within the reliability interval in most cases, the RSD value being mostly less than 2 %. In general, the separation system developed is very convenient for rapid analyses of large sets of similar samples, e.g., in product quality control or environmental monitoring