title: Separation of oxypurines by ligand-exchange chromatography and determination of caffeine in beverages and pharmaceuticals.
mesh_terms: D001628:Beverages / Q000032:analysis; D002110:Caffeine / Q000302:isolation & purification*; D002614:Chelating Agents; D055598:Chemical Phenomena; D002621:Chemistry; D002852:Chromatography, Ion Exchange; D008722:Methods; D004364:Pharmaceutical Preparations / Q000032:analysis; D011687:Purines / Q000302:isolation & purification*
chemical_list: D002614:Chelating Agents; D004364:Pharmaceutical Preparations; D011687:Purines; D002110:Caffeine