title: Simultaneous determination of codeine and its seven metabolites in plasma and urine by high-performance liquid chromatography with ultraviolet and electrochemical detection.
abstract: A sensitive and selective high-performance liquid chromatography method has been developed for the measurement of codeine and its seven metabolites, norcodeine, morphine, normorphine, codeine-6-glucuronide, morphine-6-glucuronide, morphine-3-glucuronide and norcodeine glucuronide, in plasma and urine. The compounds were recovered from plasma and urine using solid-phase extraction with C18 cartridges and separated on a reversed-phase C8 column with a mobile phase consisting of 77% buffer (5 mM sodium phosphate monobasic and 0.70 mM sodium dodecyl sulfate, pH 2.35) and 23% acetonitrile. Codeine, norcodeine, codeine-6-glucuronide, norcodeine glucuronide and morphine-3-glucuronide were detected by ultraviolet detection at 214 nm, with a detection limit of 0.02 nmol/ml for each compound in plasma. Morphine-6-glucuronide, normorphine and morphine were monitored by electrochemical detection at 350 mV, with a detection limit of 0.003 nmol/ml for each compound in plasma. The assay showed good reproducibility and accuracy using external standardization. The recovery and inter-day variation for all compounds in plasma samples were 63.40-77.90% and 3.49-16.77% (R.S.D.) and while in urine were 64.98-90.13% and 2.93-9.96% (R.S.D.), respectively.
authors.affiliation: Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232-6602, USA.
authors.forename: H
authors.initials: H
authors.lastname: He
authors.forename: S D
authors.initials: SD
authors.lastname: Shay
authors.forename: Y
authors.initials: Y
authors.lastname: Caraco
authors.forename: M
authors.initials: M
authors.lastname: Wood
authors.forename: A J
authors.initials: AJ
authors.lastname: Wood
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003061:Codeine / Q000097:blood* / Q000378:metabolism / Q000652:urine*; D004563:Electrochemistry; D006801:Humans; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013056:Spectrophotometry, Ultraviolet
chemical_list: D003061:Codeine