Estimation of the Measurement Uncertainty in Quantitative Determination of Ketamine and Norketamine in Urine Using a One-Point Calibration Method

Ma, Yi-Chun; Wang, Che-Wei; Hung, Sih-Hua; Chang, Yan‐Zin; Liu, Chia-Reiy; Her, Guor‐Rong

doi:10.1093/jat/bks062

Cited by 10 publications

(4 citation statements)

References 10 publications

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“…Ma et al, 2012 [38] EURACHEM/CITAC workshop on recent developments in measurement uncertainty. Contains a selection of the contributed papers at this workshop and show how the evaluation of uncertainty is now being applied to a wide range of analyses.…”

Section: Authorsmentioning

confidence: 99%

A Practical Way to ISO/GUM Measurement Uncertainty for Analytical Assays Including In-House Validation Data

González¹,

Herrador²,

GarcíaAsuero³

et al. 2018

Quality Control in Laboratory

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In this contribution, we outline the estimation of measurement uncertainty of analytical assays in a practical way, according to the so-called reconciliation paradigm, by considering the heritance of uncertainties according to the ISO Guide to the expression of uncertainty in measurement (ISO/GUM) approach and the accuracy (bias and precision) study coming from the in-house method validation. A cause and effect analysis is performed by using the Ishikawa diagram or fishbone plot, consisting of a hierarchical structure reaching a final outcome that is the analytical result. The procedure is illustrated with a case study. This procedure may be very suitable for processing data in accreditation of routine assays.

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Section: Authorsmentioning

confidence: 99%

A Practical Way to ISO/GUM Measurement Uncertainty for Analytical Assays Including In-House Validation Data

González¹,

Herrador²,

GarcíaAsuero³

et al. 2018

Quality Control in Laboratory

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“…The expanded uncertainties of THC-COOH and THC-COOH-glu in the sample were calculated by Equation (12). Figure 2 shows the relative contribution of four different sources of uncertainty to the overall combined standard uncertainty for the quantification of THC-COOH and THC-COOH-glu in the urine sample.…”

Section: Bias (Recovery)mentioning

confidence: 99%

“…The estimation of MU has become an issue in the quality control (QC) of forensic drug testing because it influenced the confidence of the reported results and judicial decision-making (9)(10)(11). Forensic laboratories carrying out various types of measurements are increasingly being required to evaluate the uncertainties associated with their quantitative measurement results (12)(13)(14)(15). With the adoption of ISO/ IEC (International Organization for Standardization/International Electrotechnical Commission) 17025 by most of forensic laboratories in Korea, evaluating MU is now an essential part of quantitative analysis.…”

Section: Introductionmentioning

confidence: 99%

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Estimation of Measurement Uncertainty for the Quantification of 11-Nor-Delta 9-Tetrahydrocannabinol-9-Carboxylic Acid and Its Glucuronide in Urine Using Liquid Chromatography-Tandem Mass Spectrometry

Kim

Kwon

Kim

et al. 2014

Journal of Analytical Toxicology

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Recently, the estimation of the measurement uncertainty has become a significant issue in the quality control of forensic drug testing. In the present study, the uncertainty of the measurement was calculated for the quantification of 11-nor-delta 9-tetrahydrocannabinol-9-carboxylic acid (THC-COOH) and its glucuronide conjugate (THC-COOH-glu) in urine using liquid chromatography-tandem mass spectrometry. The procedure was based on liquid-liquid extraction of a volume of urine (800 µL) with ethyl acetate. The sources of uncertainty were identified and classified into four major categories as follows: standard preparation, calibration curve, method precision and bias. The overall contribution of combined standard uncertainty on THC-COOH increased in the order of standard preparation (0.9%), method precision (10.4%), calibration curve (30.3%) and bias (58.4%) and, while calibration curve (53.0%) and bias (40.4%) gave the bigger contributions to the combined standard uncertainty for THC-COOH-glu than method precision and standard preparation, which accounted for 6.3 and 0.3%, respectively. The reliability of a measurement was expressed by stating the expanded uncertainty of the measurement result at 95% confidence level. The concentrations of THC-COOH and THC-COOH-glu in the urine sample with their expanded uncertainties were 10.20 ± 1.14 ng/mL and 25.42 ± 5.01 ng/mL, respectively.

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Assessment of simpler calibration models in the development and validation of a fast postmortem multi-analyte LC-QTOF quantitation method in whole blood with simultaneous screening capabilities using SWATH acquisition

et al. 2017

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In postmortem toxicology, fast methods can provide a triage to avoid unnecessary autopsies. Usually, this requires multiple qualitative and quantitative analytical methods. The aim of the present study was to develop a postmortem LC-QTOF method for simultaneous screening and quantitation using easy sample preparation and reduced alternative calibration models. Hence, a method for 24 highly relevant substances in forensic toxicology was fully validated using the following calibration models: one-point external, one-point internal via corresponding deuterated standards, multi-point external daily calibration, and multi-point external weekly calibration. Two hundred microliters of postmortem blood were spiked with internal deuterated standard mixture and extracted by acetonitrile protein precipitation. Analysis was performed on a Sciex 6600 QTOF instrument with ESI+ mode using data-independent acquisition (DIA) namely sequential window acquisition of all theoretical mass spectra (SWATH). Validation of the different calibration models included selectivity, autosampler stability, recovery, matrix effects, accuracy, and precision for 24 substances. In addition, corresponding deuterated analogs of 52 substances were included to the internal standard mix for semi-quantitative concentration assessment. The simple protein precipitation provided recoveries higher than 55 and 75% for all analytes at low and high concentrations, respectively. Accuracy and precision criteria (bias and imprecision ± 15 and ± 20% near the limit of quantitation) were fulfilled by the different calibration models for most analytes. The validated method was successfully applied to more than 100 authentic postmortem samples and 3 proficiency tests. Furthermore, the one-point internal calibration via corresponding deuterated standard proved to be a considerably time saving technique for 76 analytes. Graphical abstract One-point and multi-point calibration and the resulting beta-tolerance intervals from method validation.

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Estimation of the Measurement Uncertainty in Quantitative Determination of Ketamine and Norketamine in Urine Using a One-Point Calibration Method

Cited by 10 publications

References 10 publications

A Practical Way to ISO/GUM Measurement Uncertainty for Analytical Assays Including In-House Validation Data

A Practical Way to ISO/GUM Measurement Uncertainty for Analytical Assays Including In-House Validation Data

Estimation of Measurement Uncertainty for the Quantification of 11-Nor-Delta 9-Tetrahydrocannabinol-9-Carboxylic Acid and Its Glucuronide in Urine Using Liquid Chromatography-Tandem Mass Spectrometry

Assessment of simpler calibration models in the development and validation of a fast postmortem multi-analyte LC-QTOF quantitation method in whole blood with simultaneous screening capabilities using SWATH acquisition

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