title: Determination of dextromethorphan and levomethorphan in seized heroin samples by enantioselective HPLC and electronic CD.
abstract: A new enantioselective HPLC method was developed for the resolution and determination of the enantiomers of methorphan, dextromethorphan (DXM) and levomethorphan (LVM), on a Chiralcel OJ column (250 mm × 4.6mm I.D.). The resolution of DXM and LVM was obtained using a mobile phase consisting of (n-hexane)-(2-propanol)-diethylamine (70:30:0.1, v/v/v) at a flow rate of 0.5 mL min(-1). The enantioselective method was found to be selective (α=1.92) and sensitive (LOD=2.8 μg mL(-1) for both DXM and LVM). The method was coupled with electronic circular dichroism (CD), allowing the determination of the elution order on the basis of the sign of CD signals of the single enantiomers at 285 nm (positive for DXM, negative for LVM). Under the optimized conditions, the validated method was applied to the identification and quantitation of the enantiomers of methorphan in samples of different sources of illicit drugs of abuse (heroin). DXM was found in eight seized samples of street heroin; two of these samples, for which the DXM content was found to be over 5% (w/w) and exceeding a 10% (w/w) ratio with respect to diacetylmorphine, were the cause of two deaths for overdose due to acute narcotism.
authors.affiliation: Department of Pharmacy and Biotechnology, University of Bologna, Via Belmeloro 6, 40126 Bologna, Italy.
authors.forename: Daniele
authors.initials: D
authors.lastname: Tedesco
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Di Pietra
authors.forename: Francesca
authors.initials: F
authors.lastname: Rossi
authors.forename: Marco
authors.initials: M
authors.lastname: Garagnani
authors.forename: Elia
authors.initials: E
authors.lastname: Del Borrello
authors.forename: Carlo
authors.initials: C
authors.lastname: Bertucci
authors.forename: Vincenza
authors.initials: V
authors.lastname: Andrisano
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods; D002942:Circular Dichroism / Q000379:methods; D003915:Dextromethorphan / Q000032:analysis* / Q000737:chemistry; D062787:Drug Overdose; D003932:Heroin / Q000032:analysis* / Q000737:chemistry; D006801:Humans; D013287:Illicit Drugs / Q000032:analysis / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D013287:Illicit Drugs; D003932:Heroin; D003915:Dextromethorphan