A novel anti-interference and pH-modulation device: application to enzyme-free glucose detection

We report on a novel anti-interference and pH-modulation device (herein after referred to as “device”). It is based on electrodialysis and can continuously increase the pH value of the carrier solution and - at the same time - remove interfering analytical signals obtained for ascorbic acid (AA) and uric acid (UA). The “device” was coupled to the FIA-amperometric detection of glucose. The linear range is from 1 μmol L −1 to 0.4 mmol L −1 , with a sensitivity of 213 μA cm −2 mM −1 and a detection limit of 1 μmol L −1 at a signal-to-noise ratio of 3. The method was used to sucessfully determine glucose in serum. This study represents a novel technique for overcoming analytical interference and is expected to find applications in liquid chromatography, for example in on-line pH-modulation if different pH values are needed for separation and detection. Figure As shown in the figure, a specific electrolytic current was applied between the two electrodes. Thus H 2 O in the cathode chamber was electrolyzed to produce H 2 and OH - . Then the OH - moved through the anion exchange membrane and got into the packed column by electromigration, where it mixed with the carrier solution of Na 2 SO 4 . Meanwhile, the SO 4 2- of the carrier solution moved through the other anion exchange membrane and entered the anode chamber. Therefore, the carrier solution of Na 2 SO 4 was partly converted into NaOH after passing through the “device”.