Zaugg S, Zhang X, Sweedler J, Thormann W
Department of Clinical Pharmacology, University of Bern, Switzerland.
J Chromatogr B Biomed Sci Appl. 2001 Mar 5;752(1):17-31. doi: 10.1016/s0378-4347(00)00507-7.
Acetylsalicylic acid (Aspirin) is rapidly metabolized to salicylic acid (salicylate) and other compounds, including gentisic acid and salicyluric acid. Monitoring of salicylate and its metabolites is of toxicological, pharmacological and biomedical interest. Three capillary electrophoresis (CE) methods featuring alkaline aqueous buffers, laser-induced fluorescence (LIF) detection and no solute extraction or derivatization have been explored. A competitive binding, electrokinetic capillary-based immunoassay is developed that recognizes the presence of salicylate and gentisic acid in urine. Differentiation of the two compounds, however, is problematic. With appropriate ultraviolet excitation, many salicylate-related compounds are fluorescent so that CE with direct urine injection and LIF detection permits the determination of salicylate, gentisic acid and salicyluric acid. Using a HeCd laser with 325 nm produces interference-free monitoring of all three compounds. Using 257 nm excitation from a frequency doubled Ar ion laser, native fluorescence of an endogenous urinary compound that co-migrates with gentisic acid is observed. With wavelength-resolved fluorescence detection, however, the two substances are distinguished. Furthermore, this technique, with comparison to literature data, permits the putative assignment of several peaks to other salicylate metabolites, namely glucuronide conjugates of salicylate and salicyluric acid. All three CE-LIF techniques have been applied to toxicological patient urines and urines collected after ingestion of 500 mg acetylsalicylic acid. CE results compare favorably with those obtained by a commercial fluorescence polarization immunoassay and by a conventional photometric assay.
乙酰水杨酸（阿司匹林）会迅速代谢为水杨酸（水杨酸盐）及其他化合物，包括龙胆酸和水杨尿酸。监测水杨酸盐及其代谢物具有毒理学、药理学和生物医学意义。我们探索了三种毛细管电泳（CE）方法，这些方法采用碱性水性缓冲液、激光诱导荧光（LIF）检测，且无需溶质萃取或衍生化。我们开发了一种基于毛细管电动免疫分析的竞争性结合方法，可识别尿液中水杨酸盐和龙胆酸的存在。然而，区分这两种化合物存在问题。在适当的紫外激发下，许多与水杨酸盐相关的化合物具有荧光，因此直接进样尿液并采用LIF检测的CE法可测定水杨酸盐、龙胆酸和水杨尿酸。使用波长为325 nm的氦镉激光可对所有三种化合物进行无干扰监测。使用倍频氩离子激光的257 nm激发光时，会观察到一种与龙胆酸共迁移的内源性尿液化合物的天然荧光。然而，通过波长分辨荧光检测可区分这两种物质。此外，与文献数据相比，该技术还可将几个峰推测性地归属于其他水杨酸盐代谢物，即水杨酸盐和水杨尿酸的葡萄糖醛酸共轭物。所有三种CE-LIF技术均已应用于中毒患者的尿液以及摄入500 mg乙酰水杨酸后收集的尿液。CE法的结果与通过商业荧光偏振免疫分析法和传统光度分析法获得的结果相比具有优势。
