title: Analysis of trace amounts of acetylsalicylic anhydride in acetylsalicylic acid.
mesh_terms: D000812:Anhydrides / Q000032:analysis; D001241:Aspirin / Q000031:analogs & derivatives* / Q000032:analysis*; D002854:Chromatography, Paper; D004340:Drug Contamination; D008722:Methods
chemical_list: D000812:Anhydrides; D001241:Aspirin