title: Rapid and simultaneous determination of multiple classes of abused drugs and metabolites in human urine by a robust LC-MS/MS method - application to urine drug testing in pain clinics.
abstract: A simple LC-MS/MS method was developed and validated for quantitatively analyzing six classes of 26 abused drugs and metabolites in human urine: (1) illicit drugs; (2) opiates; (3) synthetic opioids; (4) sedative; (5) stimulants; and (6) γ-aminobutyric acid analogs. All urine samples were diluted with a mixture of isotope-labeled internal standards, hydrolyzed with β-glucuronidase and directly injected in a gradient chromatographic run. The mobile phase was composed of 0.1% formic acid in water and 0.1% of formic acid in methanol. A 4.9 min run time using the multiplexing driver and ultra-biphenyl column (50 × 2.1 mm, 5 µm, RESTEK) allowed all drugs to have sufficient resolution in a short elute time. The overlapping liquid chromatography runs and scheduled multiple reaction monitoring acquisition method resulted in a higher overall throughput for the system. The result was linear over the studied range (2-16,000 ng/mL) for all compounds with correlation coefficients r(2) ≥ 0.995. The intra-day and inter-day precisions and accuracies were within 15% and recovery was between 83 and 115% for all analytes. Freeze-thaw stability for three cycles and long-term stability (57 days, -20°C) were established for all analytes. The cross-validation between College of American Pathologists and in-house was validated (0.06% ≤ bias ≤ 12.3%). The applicability of the method was examined by analyzing urine samples from chronic pain patients (n = 610).
authors.affiliation: Texas Medical Toxicology, 7707 Fannin Street, Suite 290, Houston, TX, 77054, USA.
authors.forename: Jianmei
authors.initials: J
authors.lastname: Wang
authors.forename: Zhen
authors.initials: Z
authors.lastname: Yang
authors.forename: James
authors.initials: J
authors.lastname: Lechago
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000191:economics / Q000295:instrumentation / Q000379:methods*; D004867:Equipment Design; D006801:Humans; D013287:Illicit Drugs / Q000378:metabolism / Q000652:urine*; D057230:Limit of Detection; D018710:Pain Clinics; D015813:Substance Abuse Detection / Q000191:economics / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000191:economics / Q000379:methods*; D013997:Time Factors
chemical_list: D013287:Illicit Drugs
keywords: LC-MS/MS; direct injection; drugs of abuse; urine