title: Chromatographic determination of drugs of abuse in vitreous humor using solid-phase extraction.
abstract: A simple method is presented for the simultaneous determination of morphine, 6-acetylmorphine, codeine, cocaine, benzoylecgonine, cocaethylene, methadone and 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) in vitreous humor by high-performance liquid chromatography with photodiode array detector after solid-phase extraction with Oasis® HLB cartridges and dichloromethane as eluent. The chromatographic process was carried out using an XTerra® RP8 column (250 × 4.6 mm i.d., 5 µm particle size) and a mobile phase composed of acetonitrile and pH 6.5 phosphate buffer in gradient mode. A linear response from the detector was obtained within the concentration range of 0.1-4 µg ml(-1) , with correlation coefficients higher than 0.99. The limits of detection were lower than 30 ng ml(-1) for all the drugs studied, the coefficients of variation fluctuated between 0.1 and 12.4%, and the average recoveries were higher than 78% for all the drugs except for EDDP, with a value of 66.4%. Finally, the proposed method was applied to 15 vitreous humor samples coming from individuals who had died from opiate and/or cocaine overdose, showing consumption of cocaine in 14 cases, methadone in five cases and heroin in three cases. Average concentrations of 0.30 µg ml(-1) for morphine, 0.24 µg ml(-1) for 6-acetylmorphine, 0.10 µg ml(-1) for codeine, 0.81 µg ml(-1) for cocaine, 1.26 µg ml(-1) for benzoylecgonine, 0.15 µg ml(-1) for cocaethylene, 0.11 µg ml(-1) for methadone and 0.68 µg ml(-1) for EDDP were obtained.
authors.affiliation: Institute of Forensic Sciences, Forensic Toxicology Service, Faculty of Medicine, 15782-Santiago de Compostela, Spain. puri.fernandez@usc.es
authors.forename: Purificación
authors.initials: P
authors.lastname: Fernández
authors.forename: Santiago
authors.initials: S
authors.lastname: Seoane
authors.forename: Cristina
authors.initials: C
authors.lastname: Vázquez
authors.forename: María Jesús
authors.initials: MJ
authors.lastname: Tabernero
authors.forename: Antonia M
authors.initials: AM
authors.lastname: Carro
authors.forename: Rosa A
authors.initials: RA
authors.lastname: Lorenzo
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003042:Cocaine / Q000031:analogs & derivatives / Q000302:isolation & purification; D003061:Codeine / Q000302:isolation & purification; D006801:Humans; D013287:Illicit Drugs / Q000302:isolation & purification*; D009022:Morphine Derivatives / Q000302:isolation & purification; D011759:Pyrrolidines / Q000302:isolation & purification; D015203:Reproducibility of Results; D052616:Solid Phase Extraction / Q000379:methods*; D014822:Vitreous Body / Q000737:chemistry*
chemical_list: D013287:Illicit Drugs; D009022:Morphine Derivatives; D011759:Pyrrolidines; C005618:benzoylecgonine; C066444:cocaethylene; D003042:Cocaine; C026979:6-O-monoacetylmorphine; D003061:Codeine; C010724:2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine