title: Estimation of the measurement uncertainty in quantitative determination of ketamine and norketamine in urine using a one-point calibration method.
abstract: An approach was proposed for the estimation of measurement uncertainty for analytical methods based on one-point calibration. The proposed approach is similar to the popular multiple-point calibration approach. However, the standard deviation of calibration was estimated externally. The approach was applied to the estimation of measurement uncertainty for the quantitative determination of ketamine (K) and norketamine (NK) at a 100 ng/mL threshold concentration in urine. In addition to uncertainty due to calibration, sample analysis was the other major source of uncertainty. To include the variation due to matrix effect and temporal effect in sample analysis, different blank urines were spiked with K and NK and analyzed at equal time intervals within and between batches. The expanded uncertainties (k = 2) were estimated to be 10 and 8 ng/mL for K and NK, respectively.
authors: Department of Chemistry, National Taiwan University, No.1, Sec.4, Roosevelt Road, Taipei 10617, Taiwan.
authors: Yi-Chun
authors: YC
authors: Ma
authors: Che-Wei
authors: CW
authors: Wang
authors: Sih-Hua
authors: SH
authors: Hung
authors: Yan-Zin
authors: YZ
authors: Chang
authors: Chia-Reiy
authors: CR
authors: Liu
authors: Guor-Rong
authors: GR
authors: Her
mesh_terms: D002138:Calibration / Q000592:standards; D002849:Chromatography, Gas; D006801:Humans; D007649:Ketamine / Q000031:analogs & derivatives* / Q000652:urine*; D015813:Substance Abuse Detection / Q000379:methods*; D035501:Uncertainty
chemical_list: D007649:Ketamine; C033419:norketamine