title: Stable isotope method for the assay of codeine and morphine by gas chromatography-mass spectrometry. A feasibility study.
mesh_terms: D002849:Chromatography, Gas; D003061:Codeine / Q000032:analysis* / Q000097:blood / Q000652:urine; D003903:Deuterium; D006801:Humans; D008297:Male; D013058:Mass Spectrometry; D009020:Morphine / Q000032:analysis* / Q000652:urine
chemical_list: D009020:Morphine; D003903:Deuterium; D003061:Codeine