title: Separation and spectrophotometric determination of theophylline and hydroxyethyltheophylline in a pharmaceutical syrup.
abstract: A simple chromatographic procedure was developed for the separation and determination of theophylline and hydroxyethyltheophylline. An aliquot of diluted syrup was pipetted into a chromatographic column containing a strong anion-exchange resin, which retains theophylline and allows the hydroxyethyl derivative to pass through it. Theophylline was subsequently eluted with 1 N HCl and determined by difference spectrophotometry at 284 nm; its derivative was determined at 272 nm.
mesh_terms: D012996:Solutions / Q000032:analysis; D013056:Spectrophotometry, Ultraviolet; D013806:Theophylline / Q000031:analogs & derivatives* / Q000032:analysis* / Q000302:isolation & purification
chemical_list: D012996:Solutions; D013806:Theophylline; C008749:etofylline