title: Development of a clinically relevant liquid chromatography tandem mass spectrometry assay for 13 drugs of abuse in urine, designed to meet the needs of the service users.
abstract: BACKGROUND
  The clinical requirements of the users of assay results must be at the centre of assay development. We aimed to develop a single liquid chromatography tandem mass spectrometry (LC-MS/MS) assay for drugs of abuse in urine that would meet the needs of our service users and replace the multiple screening and confirmatory techniques previously in use.
  
  
  METHODS
  After discussion with our users, it was decided that 13 drugs and metabolites should be measured in our panel: morphine, codeine, norcodeine, dihydrocodeine, 6-monoacetylmorphine, acetyl codeine, methadone and its metabolite, buprenorphine and its metabolite, amphetamine, benzoylecgonine and cotinine. Urine samples were prepared by the addition of internal standard, enzymatic hydrolysis and solid-phase extraction. Chromatography conditions were optimized so that the analytes were separated within a run time of 6 min. Optimal parent to daughter m/z ion transitions were chosen for all drugs and daughter ion ratios were used.
  
  
  RESULTS
  The LC-MS/MS assay was successfully validated with acceptable precision and lower limits of quantification for all drugs. No matrix effects were seen. The results produced by the LC-MS/MS assay compared well with the previous combination of techniques in use.
  
  
  CONCLUSIONS
  We have developed and validated a fit-for-purpose LC-MS/MS assay for 13 drugs of abuse in urine that obviates the need for multiple screening and confirmatory analytical techniques.
authors.affiliation: Department of Clinical Biochemistry, Salford Royal NHS Foundation Trust, Stott Lane, Salford M68HD, UK. k.duxbury@nhs.net
authors.forename: K
authors.initials: K
authors.lastname: Duxbury
authors.forename: C
authors.initials: C
authors.lastname: Romagnoli
authors.forename: M
authors.initials: M
authors.lastname: Anderson
authors.forename: R
authors.initials: R
authors.lastname: Watts
authors.forename: G
authors.initials: G
authors.lastname: Waite
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006801:Humans; D013287:Illicit Drugs / Q000652:urine*; D057230:Limit of Detection; D016014:Linear Models; D015813:Substance Abuse Detection / Q000379:methods*; D016320:Substance Abuse Treatment Centers; D053719:Tandem Mass Spectrometry / Q000379:methods*; D016482:Urinalysis / Q000379:methods*
chemical_list: D013287:Illicit Drugs