title: A fast screening procedure for ketamine and metabolites in urine samples with tandem mass spectrometry.
abstract: A screening method based on electrospray tandem mass spectrometry (MS-MS) was developed. Urine samples were spiked with ketamine-d(4) and norketamine-d(4) as internal standard and extracted with 0.5 mL ethyl acetate. Extracted samples were monitored with triple-quadrupole MS-MS. Total analysis time was 1.5 min/sample. Limit of detection was 0.1 ng/mL for ketamine, norketamine, and dehydronorketamine (DHNK). Carryover rate was less than 0.06%. Within-run and between-run precision for ketamine, norketamine, and DHNK at three different concentrations (40, 75, and 125 ng/mL) was between 2.1 and 8.2%. Within-run and between-run accuracy, presented as % bias, was between -5.9 and 2.7%. A group of 76 urine samples were screened with ELISA and gas chromatography-mass spectrometry (GC-MS). With GC-MS as the reference method, when ketamine, norketamine, and DHNK were monitored at cutoff concentration of 100 ng/mL, there were 21 positive, 45 negative, 7 false-negative, and 3 false-positive results. A group of 243 samples was screened with MS-MS and analyzed with GC-MS; there were 74 positive, 163 negative, 6 false-positive, and no false-negative results. In conclusion, the MS-MS procedure is accurate, efficient, and suitable for use as a high-throughput screening method for ketamine and metabolites.
authors.affiliation: Center for Drug Analysis, Tzu Chi University, 701 Section 3 Chung Yan Road, Hualien, Taiwan.
authors.forename: Huei R
authors.initials: HR
authors.lastname: Lin
authors.forename: Hsiu L
authors.initials: HL
authors.lastname: Lin
authors.forename: Shu F
authors.initials: SF
authors.lastname: Lee
authors.forename: Chiareiy
authors.initials: C
authors.lastname: Liu
authors.forename: Ahai C
authors.initials: AC
authors.lastname: Lua
mesh_terms: D002138:Calibration; D004797:Enzyme-Linked Immunosorbent Assay; D005189:False Positive Reactions; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D007649:Ketamine / Q000031:analogs & derivatives / Q000378:metabolism* / Q000652:urine*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization; D015813:Substance Abuse Detection / Q000379:methods*; D019966:Substance-Related Disorders / Q000175:diagnosis / Q000652:urine; D053719:Tandem Mass Spectrometry
chemical_list: D007649:Ketamine; C033419:norketamine