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.