The Mechanism of Schiff Test for Uric Acid in Urine
Uric acid in urine can be detected by reaction with silver nitrate in alkaline medium. A redox reaction occurs and black elemental silver is observed in the filter paper used in this test. However, the mechanism of the series of steps occurring in the uric acid molecule, including a second redox reaction, has not been advanced. A reaction route is provided, each step is fully commented giving also the electron flow. The mechanism involves free radicals and ionic intermediates as well. There is ring contraction with concomitant oxo-aziridine formation, imide hydrolysis, imine hydration to carbinol-amine, isomerization to ketone with concurrently ring opening, and assisted decarboxylation.
Uric Acid Urine Test. WebMD. Retrieved from: https://www.webmd.com>uric-acid-urine-test
Uric acid – blood. UCSF Health. Retrieved from: https://www.ucsfhealth.org>medical-tests>uric-acid
Cirillo, P., Sato, W., Reungjui, S., et al. (2006). Uric acid, the metabolic syndrome, and renal disease. Journal of the American Society of Nephrology, 17(12, Supplement 3), S165-S168. https://doi.org/10.1681/ASN.2006080909
Zhao, J., & Huang, Y. (2015). Salivary uric acid as a non invasive biomarker for monitoring the efficacy of urate-lowering therapy in a patient with chronic gouty arthropathy. Clinica Chimica Acta, 450, 115-120. https://doi.org/10.1016/j.cca.2015.08.005
Sánchez-Viesca, F., & Gómez, R. (2023). The chemistry of Mandelin’s test for strychnine. Open Access Research Journal of Chemistry and Pharmacy, 03(01), 001-004. https://doi.org/10.53022/oarjcp.2023.3.1.0040
Sánchez-Viesca, F., & Gómez, R. (2022). The chemistry of the Heller’s test for urine indican detection. Magna Scientia Advanced Research & Reviews, 05(01), 025-029. https://doi.org/10.30574/msarr.2022.5.1.0038
Sánchez-Viesca, F., & Gómez, R. (2022). The mechanism of the oxido degradation of the Cinchona alkaloids. American Journal of Chemistry, 12(1), 18-21. https://doi.org/10.5923/j.chemistry.20221201.03
Sánchez-Viesca, F., & Gómez, R. (2021). The chemistry of Crismer’s test for glucose in urine. Open Access Research Journal of Chemistry & Pharmacy, 01(02), 005-008. https://doi.org/10.53022/oarjcp.2021.1.2.0028
Sánchez-Viesca, F., & Gómez, R. (2021). On the mechanism of the Caro synthesis of methylene blue. Earthline Journal of Chemical Sciences, 6(2), 209-214. https://doi.org./10.34198/ejcs.6221.209214
Merck, E. (1903). Merck’s Reagentien-Verzeichnis (p. 129). Darmstadt, Germany: Springer. https://doi.org./10.1007/978-3-642-99730-3
Cohn, A.I. (1903). Tests and reagents (p. 271). New York, USA: J. Wiley & Sons.
Hartman, W.W., Moffett, E.W., & Dickey, J.B. (1943). Allantoin. Organic Syntheses, 2, 21-22. https://doi.org/10.15227/orgsyn.013.0001
Giral, F., & Rojahn, C.A. (1956). Productos Químicos y Farmacéuticos (Vol. 3, pp. 1821-1823). Mexico City: Atlante.
Mulder, E. (1871). Sur l’allantoine et ses dérivés, Bulletin de la Societé Chimique de Paris, 16, 267-270.
Lead Dioxide (2020). U.S. National Library of Medicine. Online Access with the title. Last login, February 1, 2023. PubChem, CID 10198636
White, J.H. (1962). Inorganic chemistry (305 pp.). London, UK: University of London Press.
Venable, C.S. (1918). The action of hydrogen peroxide upon uric acid. Journal of the American Chemical Society, 40(7), 1099-1120. https://doi.org/10.1021/ja02240a014
Gatewood, E.S. (1919). The action of hydrogen peroxide and alkali on some uric acid derivatives. Columbia, B.S. Barnard College, Columbia University.
Sánchez-Viesca, F., & Gómez, R. (2020). On the mechanism of uric acid oxidation with lead dioxide and with alkaline hydrogen peroxide. Indian Journal of Advances in Chemical Science, 8(3), 78-80. https://doi.org/10.22607/IJACS.2020.803001
Cohn, A.I. (1903). Tests and reagents (p. 217). New York, USA: J. Wiley & Sons.
Neubauer, C., & Vogel, J.A. (1863). A guide to the qualitative and quantitative analysis of the urine, designed especially for the use of medical men (p. 20). London, UK: New Sydenham Society (Series).
WorldCat Identities: Carl Neubauer. Online access with the title. Last login, February 1, 2023. https://worldcat.org/identities/lccn-no99086791/
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