Barroso, M Mixed-mode solid-phase extraction for sample cleanup in hair analysis for methadone and its main metabolite. [electronic resource] - Biomedical chromatography : BMC Nov 2010 - 1240-6 p. digital Publication Type: Evaluation Study; Journal Article ISSN: 1099-0801 Standard No.: 10.1002/bmc.1434 doi Subjects--Topical Terms: Analgesics, Opioid--analysisGas Chromatography-Mass SpectrometryHair--chemistryHumansMethadone--analysisSolid Phase Extraction--methods