Simultaneous determination of uric acid and ascorbic acid using edge plane pyrolytic graphite electrodes

Edge plane pyrolytic graphite electrodes have been applied for the determination of uric acid and ascorbic acid. The separate determination of uric acid was found to produce three linear ranges from 100 nM to 3400 μM with a detection limit of 30 nM found to be possible. Uric acid detection was also explored in the presence of 200 μM ascorbic acid where a detection limit of 52 nM was found to be possible. The detection of ascorbic acid in the presence of uric acid was also explored over three linear ranges of ascorbic acid with a limit of detection of 80 nM. Last the simultaneous determination of both uric acid and ascorbic acid is investigated over the range 100 nM to 1000 μM where detection limits of 50 nM and 120 nM were obtained respectively. Analysis of uric acid in a growth tissue medium was found to be successful, confirming the applicability of the methodology to real matrices. This protocol is shown to provide low detection limits, easy handling (no electrode modification), good voltammetric peak separation of uric acid and ascorbic acid and a wide linear dynamic range. © 2006 Wiley-VCH Verlag GmbH and Co. KGaA