Chen, B H Comparison of derivatives for determination of codeine and morphine by gas chromatography/mass spectrometry. [electronic resource] - Journal of analytical toxicology - 12-7 p. digital Publication Type: Comparative Study; Journal Article ISSN: 0146-4760 Standard No.: 10.1093/jat/14.1.12 doi Subjects--Topical Terms: AcetamidesAnhydridesBenzoatesChemical PhenomenaChemistryCodeine--analysisFluoroacetatesFluorocarbonsGas Chromatography-Mass SpectrometryIndicators and ReagentsMorphine Derivatives--analysisNalorphine--analysis