title: The influence of blood sample preparation on measured levels of morphine and its major metabolites.
abstract: The effect of six different methods of blood sample preparation on concentrations of morphine (M), morphine-3-glucuronide (M3G) and morphine-6-glucuronide (M6G) have been investigated using a specific high performance liquid chromatography assay. No difference between glass or plastic tubes was seen in concentrations of M, M3G, or M6G; and no difference between plasma and serum in M and M6G concentrations. M3G concentrations, however, were significantly lower in plasma compared with serum. Heparin had no effect on M, M6G or M3G, whereas citrate in a glass tube produced consistently lower concentrations of M, M3G and M6G. Standardization of sample collection using plasma samples in plastic heparin tubes is recommended for future studies.
authors.affiliation: Continuing Care Unit, Royal Marsden Hospital, Sutton, Surrey, UK.
authors.forename: P J
authors.initials: PJ
authors.lastname: Hoskin
authors.forename: O
authors.initials: O
authors.lastname: Alsayed-Omar
authors.forename: G W
authors.initials: GW
authors.lastname: Hanks
authors.forename: A
authors.initials: A
authors.lastname: Johnston
authors.forename: P
authors.initials: P
authors.lastname: Turner
mesh_terms: D002851:Chromatography, High Pressure Liquid; D006801:Humans; D009020:Morphine / Q000097:blood* / Q000378:metabolism; D009022:Morphine Derivatives / Q000008:administration & dosage / Q000097:blood*; D013048:Specimen Handling
chemical_list: D009022:Morphine Derivatives; C035349:morphine-6-glucuronide; D009020:Morphine; C018108:morphine-3-glucuronide