title: Analysis of opium and crude morphine samples by capillary gas chromatography. Comparison of impurity profiles.
mesh_terms: D000107:Acetylation; D002849:Chromatography, Gas / Q000379:methods; D004340:Drug Contamination; D003932:Heroin / Q000032:analysis; D013287:Illicit Drugs / Q000032:analysis; D009020:Morphine / Q000032:analysis*; D009892:Opium / Q000032:analysis*
chemical_list: D013287:Illicit Drugs; D003932:Heroin; D009020:Morphine; D009892:Opium