Simultaneous determination of acetylsalicylic acid non-enzyme mediated oxidative products.
Toxicologist 2003 Mar; 72(S-1):50
Aspirin (ASP) is a commonly used analgesic and anti-inflammatory agent. After ingestion, it is hydrolyzed to salicylic acid (SA) by esterase in the gastrointestinal tract and in liver. We found that ASP can be oxidized to SA without enzyme. On the other hand, SA can react with hydroxyl radical to form its derivatives, 2,3-dihydroxybenzoate and 2,5-dihydroxybenzoate. The reaction system consisted of hydrogen peroxide (H2O2), ferrous iron (Fe2+) and ASP or SA. The hydroxyl radical production in the Fenton reaction was confirmed by electron spin resonance (ESR) in combination with spin trapping technique. The assay of ASP oxidative products was performed on high-performance liquid chromatography (HPLC) equipped with UV-visible diode array detector and an XTerra Phenyl column (3.5 um, 2.1 mm x 150 mm). The mobile phase consisted of 0.3% formic acid and acetonitrile at the gradient ratios from 85:15 for 3 min to 80:20 for 6 min and kept for 1 min, then back to 85:15 for 1 min at a constant flow rate of 0.3 mL/min. The compounds were monitored at 230 nm and a reference wavelength 360 nm with 100 nm widths. Benzoic acid was used as the internal standard for quantification. A detection limit of less than 5 ng per injection for these products could be achieved. The reproducibility was found to be better than 10%. The method also could be used to evaluate the in vivo and in vitro oxidative stress induced by toxicant dermal exposure.
Pharmacodynamics; Pharmacology; In-vivo-studies; In-vitro-studies; Analytical-methods; Analytical-processes
Disease and Injury: Allergic and Irritant Dermatitis
The Toxicologist. Society of Toxicology 42nd Annual Meeting and ToxExpo, Cutting-Edge Science, Networking, New Perspectives, March 9-13, 2003, Salt Lake City, Utah