title: Development of a method for the analysis of drugs of abuse in vitreous humor by capillary electrophoresis with diode array detection (CE-DAD).
abstract: This work presents the development of an analytical method based on capillary electrophoresis with diode array detection for the analysis of drugs of abuse and biotransformation products in vitreous humor. Composition of the background electrolyte, implementation of an online pre-concentration strategy and sample preparation procedures were objects of study. The complete electrophoretic separation of 12 analytes (amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxyethylamphetamine (MDEA), ketamine, cocaine, cocaethylene, lidocaine, morphine, 6-monoacetylmorphine and heroin) and the internal standard N-methyl-1-(3,4-methylenedioxyphenyl)-2-butamine (MBDB) was obtained within 13min of run. The method was validated presenting good linearity (r(2)>0.99), recovery ≥90%, precision better than 12% RSD and acceptable accuracy in the range of 86-118% at three concentration levels (50, 100 and 500ng/mL). LODs and LOQs in the order of 1-5ng/mL and 5-10ng/mL, respectively, were obtained. After validation, the method was applied to eighty-seven vitreous humor samples and the results were compared to those obtained by a liquid chromatography tandem mass spectrometry (LC-MS/MS) screening method, routinely used by the forensic toxicology laboratory of the Sao Paulo State Police, Brazil. Cocaine was detected in 7.1%, cocaethylene in 3.6%, lidocaine in 2.4% and ketamine in 1.2% of the total number of analyzed samples.
authors: Forensic Toxicology and Chemistry Laboratory, Criminalistics Institute of São Paulo, Sao Paulo, SP, Brazil; Institute of Chemistry, University of Sao Paulo, Sao Paulo, SP, Brazil.
authors: Jose Luiz
authors: JL
authors: Costa
authors: Institute of Legal Medicine, Sao Paulo State Police, Sao Paulo, Brazil.
authors: Andre Ribeiro
authors: AR
authors: Morrone
authors: Department of Biochemistry and Immunology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil.
authors: Rodrigo Ribeiro
authors: RR
authors: Resende
authors: Faculty of Pharmaceutical Sciences, University of Sao Paulo, Sao Paulo, Brazil.
authors: Alice Aparecida da Matta
authors: AA
authors: Chasin
authors: Institute of Chemistry, University of Sao Paulo, Sao Paulo, SP, Brazil. Electronic address: mfmtavar@iq.usp.br.
authors: Marina Franco Maggi
authors: MF
authors: Tavares
mesh_terms: D002853:Chromatography, Liquid; D019075:Electrophoresis, Capillary / Q000379:methods*; D006801:Humans; D013287:Illicit Drugs / Q000032:analysis* / Q000302:isolation & purification; D057230:Limit of Detection; D015813:Substance Abuse Detection / Q000379:methods*; D053719:Tandem Mass Spectrometry; D014822:Vitreous Body / Q000737:chemistry*
chemical_list: D013287:Illicit Drugs
keywords: Capillary zone electrophoresis; Cocaine; Forensic toxicology; Liquid chromatography–mass spectrometry; Vitreous humor