High performance anion-exchange chromatography electro-chemical determination of uric acid as a contamination marker

Honeychurch, Kevin

Abstract

This study presents the first instance of determining environmental uric acid in urban dust using high-performance anion-exchange chromatography coupled with electrochemical detection. The optimum chromatographic conditions were identified as a 10 mm x 4.6 mm, 10 µm anion exchange column with a mobile phase of pH 8 50 mM phosphate buffer. Cyclic voltammetric investigations over the pH range 2 to 12 showed that uric acid gave a single diffusion-controlled peak. Hydrodynamic voltammetric studies of uric acid using a mobile phase of 50 mM pH 8.0 phosphate buffer, over the range 0.0 V to +1.4 V (vs. stainless steel) showed a similar single oxidation wave which plateaued at potentials more positive than +0.7 V (vs. stainless steel). An applied potential of +0.90 V (vs. stainless steel) was chosen for further investigations, and a linear range of 0.10 to 100 mg/L was obtained, with a detection limit of 0.866 mg/L based on a signal-to-noise ratio of three. Dust wipe samples were extracted in pH 8, 50 mM phosphate buffer with the aid of sonication. Recoveries of 99.6 % (% CV = 4.52 %) were achieved for dust wipe fortified at 16.8 µg of uric acid. Nitrate, nitrite, chloride, acetate and sulphate ions were found not to interfere. Dust wipe samples were found to have uric acid levels of between 32.6 µg/m2 and 3.98 mg/m2.

• Journal Article Type: Article
• Acceptance Date: Mar 26, 2025
• Online Publication Date: Apr 1, 2025
• Publication Date: Apr 1, 2025
• Deposit Date: Apr 1, 2025
• Publicly Available Date: Apr 1, 2025
• Journal: Sci
• Electronic ISSN: 2413-4155
• Publisher: MDPI
• Peer Reviewed: Peer Reviewed
• Volume: 7
• Issue: 2
• Article Number: 40
• DOI: https://doi.org/10.3390/sci7020040
• Keywords: uric acid; high-performance anion exchange chromatography; electrochemical detection; environmental contamination; dust wipe sampling; cyclic voltammetry
• Public URL: https://uwe-repository.worktribe.com/output/14160376