title: Determination of ketamine and its major metabolite, norketamine, in urine and plasma samples using microextraction by packed sorbent and gas chromatography-tandem mass spectrometry.
abstract: Ketamine is a club drug widely abused for its hallucinogenic effects, being also used as a "date-rape" drug in recent years. We have developed an analytical method using gas chromatography-tandem mass spectrometry (GC-MS/MS) for the identification and quantification of ketamine and its major metabolite in urine and plasma. No derivatization step is needed to accomplish analysis. The compounds were extracted from 0.25mL of sample using microextraction by packed sorbent on mixed mode (M1) cartridges. Calibration curves were linear in the range of 10-250ng/mL for urine and 10-500ng/mL for plasma, with determination coefficients higher than 0.99. The limit of detection (LOD) was 5ng/mL for both compounds in both specimens. Recoveries ranged from 63 to 101%, while precision and accuracy were below 14% and 15%, respectively. These low limits of detection and the quite high recoveries obtained, in very low sample amounts, allow detecting small quantities of the compounds, making this procedure suitable for those laboratories performing routine analysis in the field of forensic toxicology. Compared with existing methods, the herein described procedure is fast, since no derivatization step is required, and cost effective for the quantification of ketamine and norketamine in biological specimens by gas chromatography.
authors.affiliation: CICS-UBI-Centro de Investigação em Ciências da Saúde, Universidade da Beira Interior, Av. Infante D. Henrique, 6201-556 Covilhã, Portugal.
authors.forename: Ivo
authors.initials: I
authors.lastname: Moreno
authors.affiliation: Instituto Nacional de Medicina Legal e Ciências Forenses-Delegação do Sul, Rua Manuel Bento de Sousa, 3, 1169-201 Lisboa, Portugal.
authors.forename: Mário
authors.initials: M
authors.lastname: Barroso
authors.affiliation: CICS-UBI-Centro de Investigação em Ciências da Saúde, Universidade da Beira Interior, Av. Infante D. Henrique, 6201-556 Covilhã, Portugal.
authors.forename: Ana
authors.initials: A
authors.lastname: Martinho
authors.affiliation: Servicio de Toxicologia Forense-Instituto de Ciencias Forenses Luís Concheiro, Universidad de Santiago de Compostela, San Francisco s/n, 15782 Santiago de Compostela, Spain.
authors.forename: Angelines
authors.initials: A
authors.lastname: Cruz
authors.affiliation: CICS-UBI-Centro de Investigação em Ciências da Saúde, Universidade da Beira Interior, Av. Infante D. Henrique, 6201-556 Covilhã, Portugal. Electronic address: egallardo@fcsaude.ubi.pt.
authors.forename: Eugenia
authors.initials: E
authors.lastname: Gallardo
mesh_terms: D002138:Calibration; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006801:Humans; D007649:Ketamine / Q000031:analogs & derivatives* / Q000097:blood* / Q000652:urine*; D057230:Limit of Detection; D012015:Reference Standards; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D007649:Ketamine; C033419:norketamine
keywords: Biological samples; GC–MS/MS; Ketamine; MEPS; Norketamine