Related Experiment Video
Updated: May 16, 2026

High-throughput and Comprehensive Drug Surveillance Using Multisegment Injection-Capillary Electrophoresis-Mass Spectrometry
Published on: April 23, 2019
Measurement uncertainty in urine drug analysis: A comparison of ISO/TS 20914 and GUM/Eurachem approaches
Mehmet Şeneş1, Medine Alpdemir1, Emine Feyza Yurt1
1Department of Medical Biochemistry, University of Health Sciences Ankara Training and Research Hospital, Türkiye.
Background:
Urine drug screening and confirmation tests play a critical role in forensic and clinical toxicology applications. This study evaluates and methodologically compares ISO/TS 20914 and GUM/EURACHEM approaches for estimating measurement uncertainty of multiple drugs of abuse analyzed by LC-MS/MS.
Methods:
Seventeen target analytes, including drugs of abuse and their metabolites, were analyzed by LC-MS/MS, and measurement uncertainty was estimated using calibration data, one-year internal quality control results, and external quality assessment data according to both GUM/EURACHEM and ISO/TS 20914 approaches (95% confidence, k = 2).
Results:
The GUM/EURACHEM approach yielded higher uncertainty estimates than ISO/TS 20914 for all analytes, primarily due to calibration and preparation components. The highest expanded uncertainty was observed for buprenorphine and heroin (17.7%) and the lowest for MDEA (5.9%). Relative differences (%ΔU) consistently favored the ISO/TS 20914 approach, with the calibration curve being the main contributor in the GUM/EURACHEM model.
Conclusions:
The ISO/TS 20914 approach provides a practical and sustainable framework for routine high-throughput toxicology laboratories, whereas the GUM/EURACHEM approach is more suitable for detailed uncertainty assessment during method development and validation. Measurement uncertainty should be considered in result interpretation, particularly for samples near decision thresholds, where it may influence classification and impact forensic and clinical decision-making.
More Related Videos
07:57Quantitative Detection of Trace Explosive Vapors by Programmed Temperature Desorption Gas Chromatography-Electron Capture Detector
Published on: July 25, 2014
08:41Integration of Miniaturized Solid Phase Extraction and LC-MS/MS Detection of 3-Nitrotyrosine in Human Urine for Clinical Applications
Published on: July 14, 2017
Related Concept Videos
Uncertainty: Overview
Drug Dissolution: Requirements and Profile Comparison
Renal Drug Clearance: Comparison Between Renal Excretion Methods
Renal clearance is often associated with the renal glomerular filtration rate (GFR), which represents the rate at which plasma is filtered through the glomeruli in the kidney. When drug reabsorption is minimal and there is no active secretion, renal clearance is closely related to the...
Uncertainty in Measurement: Accuracy and Precision
One-Compartment Open Model: Urinary Excretion Data and Determination of k
Uncertainty in Measurement: Reading Instruments