title: A sensitive liquid chromatographic assay for plasma aspirin and salicylate concentrations after low doses of aspirin.
abstract: An original, highly sensitive and specific high performance liquid chromatographic method has been developed for the measurement of aspirin and salicylate in plasma. Minimum concentrations of 10 micrograms/L (aspirin) and 0.5 mg/L (salicylate) can be measured using 1 ml of plasma. After collection, plasma is first treated with physostigmine sulfate to inhibit enzymatic hydrolysis of aspirin to salicylate. Maximal recovery is achieved using an acid extraction into anhydrous diethyl ether with a subsequent drying-down step in an iced water bath. Aspirin and salicylate are separated by elution with a mixture of methanol, 1-butanol, orthophosphoric acid, and water on a reversed-phase octadecyl silane column at 47 degrees C and detected at 234 nm by ultraviolet absorption. Quantitation is achieved using the peak height ratio of aspirin and salicylate to internal standard (m-anisic acid). The assay has been used for the study of simultaneous aspirin and salicylate pharmacokinetics after a single oral dose of 100 mg soluble glycinated aspirin for platelet antiaggregatory therapy in six subjects, one of whom was also studied after receiving a 600 mg dose.
mesh_terms: D000328:Adult; D001241:Aspirin / Q000008:administration & dosage / Q000097:blood*; D002853:Chromatography, Liquid; D005260:Female; D006801:Humans; D007700:Kinetics; D008297:Male; D012459:Salicylates / Q000097:blood*; D020156:Salicylic Acid; D013056:Spectrophotometry, Ultraviolet
chemical_list: D012459:Salicylates; D020156:Salicylic Acid; D001241:Aspirin