title: Spectrophotometric determination of microgram quantities of acetylsalicylic anhydride in acetylsalicylic acid.
mesh_terms: D000812:Anhydrides / Q000032:analysis*; D001241:Aspirin / Q000032:analysis*; D001583:Benzoxazoles; D000431:Ethanol; D008722:Methods; D013056:Spectrophotometry, Ultraviolet
chemical_list: D000812:Anhydrides; D001583:Benzoxazoles; D000431:Ethanol; D001241:Aspirin