It is important for a testing laboratory to proactively identify risks so as to prevent or reduce the occurrence of failures in the laboratory activities and to ascertain the validity and reliability of test results. The ISO/IEC 17025:2017 standard requires the laboratory to identify specific risks such as those related to impartiality and laboratory activities. The standard also requires the laboratory to carry out actions to address the identified risks. Although the standard does not require the laboratory to follow a formal method of risk management or a documented risk management process, the laboratory should try its best to develop a documented system for efficient risk management. This article aims to provide practical insights and guidance for testing laboratories seeking to develop comprehensive risk management practices to fulfill the requirements of the ISO/IEC 17025:2017 standard. By embracing a robust risk management framework, the testing laboratories can protect the integrity of their results, ensure the safety of the staff, enhance the quality of their services, and promote compliance to the ISO/IEC 17025:2017 standard, ultimately fostering trust and confidence among stakeholders.
Proficiency testing (PT) programmes in mycotoxin analysis predominantly rely on the z-score for participant performance evaluation, which does not incorporate the laboratory's reported measurement uncertainty. In this study, 2,538 results from 15 mycotoxin PT rounds conducted between 2020 and 2025 were analysed using a binary classification framework comprising 12 probability categories (P1 to P12), based on the combined evaluation of z-scores, ζ-scores, and measurement uncertainty adequacy. The analysis revealed that a substantial proportion of results classified as satisfactory under z-score-only evaluation were reclassified as unsatisfactory when the ζ-score was applied, showing that z-score-only assessment may overlook results for which the observed deviation is inconsistent with the participant-reported measurement uncertainty. Measurement uncertainty underestimation was markedly more prevalent than overestimation, and the mathematically constrained P6 category and the mathematically excluded P8 category were not observed in the dataset. These findings support consideration of ζ-score evaluation alongside structured measurement uncertainty assessment in mycotoxin PT programmes, particularly in regulatory contexts where performance classifications may inform accreditation and regulatory oversight.
Artificial intelligence (AI) is increasingly being explored for laboratory testing, calibration, data management, and decision support. For laboratories operating within ISO/IEC 17025-oriented quality systems, however, AI adoption raises specific questions about validation, metrological traceability, measurement uncertainty, data integrity, impartiality, and human accountability. This study is presented as a structured systematic review with thematic synthesis and ISO/IEC 17025 clause mapping. Thirty peer-reviewed studies were included in the qualitative evidence synthesis, while metrological, accreditation, and AI governance documents were used as contextual sources for standards-oriented interpretation. The review shows that most available evidence comes from laboratory-adjacent settings such as clinical diagnostics, environmental sensor calibration, laboratory information systems, and AI governance, rather than from laboratories explicitly accredited to ISO/IEC 17025. The strongest technical evidence relates to analytical pattern recognition and sensor calibration, whereas direct evidence for accreditation governance, uncertainty treatment, and routine operational validation remains limited. The principal gap is the lack of standardized validation and governance frameworks for deploying AI in testing and calibration environments. The proposed framework therefore positions AI as a controlled support tool rather than an autonomous decision-maker and links each AI use case to documented validation, GUM-based uncertainty evaluation where applicable, traceability evidence, change control, audit trails, and authorized signatory review. The paper contributes a clause-by-clause mapping and an operational lifecycle for AI adoption in ISO/IEC 17025-oriented laboratory systems.
This study presents a practical, evidence-based approach to improving local or outdated standard methods by making effective use of validated leftover materials from proficiency testing (PT) schemes. Rather than limiting their use to routine internal quality control (IQC), these well-characterized materials were employed under real laboratory conditions to reveal subtle methodological gaps within existing standard procedures. A case study—histamine in tuna—demonstrates how empirical PT data can expose systematic biases and support the revision of a local standard method. The findings provide supporting evidence that PT leftovers, when properly evaluated for stability and assigned values, can serve as fit-for-purpose evaluation materials for real-world method verification. Overall, this work highlights the potential of PT leftovers as powerful tools for advancing continuous improvement and evidence-based updates in local standardization systems.
Vendor-generated instrument performance verification (IPV) records for inductively coupled plasma mass spectrometry (ICP-MS) are often retained in laboratory archives as pass/fail-oriented documents, but their retrospective record-review value depends on numeric extractability, applicable specification limits, record provenance, and duplicate/overlap control. This study presents an evidence-graded retrospective record-level screening framework for heterogeneous ICP-MS IPV records. The framework combines evidence grading, documentation coding, duplicate/overlap reconciliation, record-specific limit matching, normalized distance-to-limit (NDL), and a six-field Metric Completeness Index (MCI). It was applied as a single-laboratory case demonstration to 24 primary records after duplicate/overlap reconciliation from two PerkinElmer platforms: NexION 300 (16 records, 2012–2025) and NexION 1000 (8 records, 2020–2025). The final inventory contained 21 Grade 1 records, one Grade 4 record, and two Grade 5 preventive-maintenance IPV (PM-IPV) records; only Grade 1 and Grade 2 records were eligible for NDL. Median MCI was 100
Metrology—the science of measurement—underpins innovation, trade, and evidence-based decision-making, yet its foundational role in discussions of technological progress is often overlooked. This article explores the findings of NPL’s most recent foresighting exercise, which examines how global change and emerging technologies are reshaping the role of metrology in the future of innovation. Four key drivers: wellbeing, enterprise, sustainability, and security, frame the conclusions, highlighting challenges from decentralised healthcare and quantum technologies to climate monitoring and cybersecurity. They also emphasise the increasing complexity of systems—especially biological, technological, and societal—that metrology must help to understand and manage. An argument is made for a cultural shift towards a “metrology mindset” and the evolving role of National Metrology Institutes (NMIs) in delivering this vision as agile, digital, and globally collaborative centres of trust in data is outlined. By embedding metrological principles into every stage of research and innovation, NMIs can ensure that science continues to improve lives, drive prosperity, and safeguard the planet. The document aims to start a renewed dialogue among metrologists and stakeholders about this vision for the future by describing some important future challenges for NMIs.
This study evaluates the batch-to-batch pH reproducibility of the NMIJ pH Certified Reference Material (CRM) tetraoxalate, phthalate, equimolal phosphate, physiological phosphate and borate buffers. Values of certified pH(S) for each CRM issue for those solutions are presented for the measurement temperature 25 °C. Values of |ΔpH(S)|<0.003, the difference between the pH(S) of each new batch and the reference values RV, the mean of all pH(S) values over twenty-years-long period are in a good agreement with the previously published results of NIST longitudinal meta-analysis and may serve as an experimental confirmation for the requirement of reproducibility for pH primary method of measurements.
Quantitative determination of ethanol in blood is a routine, widely used, and high-value assay in forensic toxicology. Because blood alcohol concentration results serve as key evidence for conviction and sentencing in many regions, laboratories continually prioritize within-laboratory data quality and interlaboratory consistency. Drawing on proficiency-testing data from 4073 laboratories collected from 2016 to 2023, this study evaluates how sample concentrations, quantification approaches, and analytical techniques affect accuracy and interlaboratory consistency. The results demonstrate the value of proficiency testing for interlaboratory quality control, while indicating that, when analyzing low-concentration samples that exhibit high variability, laboratories are likelier to achieve satisfactory rates if they follow standard recommendations and use headspace gas chromatography, internal standard quantification, and dual-column systems (p < 0.05). Accordingly, this study presents quality-control recommendations centered on quantitative headspace sampling with an internal standard, dual-column verification, and concentration-dependent evaluation and explains how these recommendations have informed updates to the Chinese national standard GB/T 42430-2023, examination methods for ethanol, methanol, n-propanol, acetone, isopropanol, and n-butanol in blood and urine.
Evaluation of measurement uncertainty is a critical requirement for laboratories accredited to ISO/IEC 17025, particularly in the specialized nutrition industry where rigorous microbiological safety criteria protect vulnerable populations. However, quantifying uncertainty in quantitative microbiological testing faces unique challenges due to biological variability and matrix heterogeneity, rendering the classical bottom-up approach impractical. This Practitioner’s Report presents the development and application of a practical Reference Guide based on the holistic top-down strategy recommended by ISO 19036. While the standard normatively permits the use of either interlaboratory study data or internal replication matrixes, this guide focuses strictly on the intralaboratory pathway. The guide uses the pooled intra-laboratory reproducibility standard deviation to evaluate combined standard uncertainty. The operational framework was verified through a case study for the enumeration of molds (Aspergillus brasiliensis) in skimmed milk powder. Results demonstrated an expanded uncertainty of 0.2 log10 CFU/g. To facilitate practical compliance interpretation at borderline zones, this log-uncertainty is mathematically reconverted at the critical control threshold (< 10 CFU/g), yielding an asymmetrical linear operational interval of 6.3 to 15.8 CFU/g. This approach successfully aligns the measurement uncertainty profile with routine industrial manufacturing specifications. This work provides a traceable operational roadmap for industrial testing facilities, ensuring regulatory compliance and measurement reliability in commercial release decisions for sensitive product batches.
An estuarine sediment IAEA-158 developed by the Marine Environment Laboratories of the International Atomic Energy Agency (IAEA), originally produced in 2008 as a reference material through an interlaboratory comparison, has now been recertified as certified reference material IAEA-158A in accordance with ISO 17034:2016 and ISO 33405:2024 principles. The recertification process involved a comprehensive homogeneity and stability assessment, followed by an extensive characterization campaign to ensure accuracy and consistency. The newly certified material includes 27 analytes covering major elements (MEs), trace elements (TEs) and rare earth elements (REEs). Although REEs are chemically a specific subgroup of trace elements, they are considered here as a distinct analyte group due to their coherent geochemical behavior and analytical relevance. In addition, information values were assigned for 21 analytes, including methylmercury (MeHg). By meeting ISO 17034:2016 requirements, IAEA-158A guarantees traceability and realistic uncertainty budget, making it a valuable quality assurance tool for laboratories worldwide. This paper details complete preparation procedure and scientific approach used for the recertification of IAEA-158A.
Imagine a worldwide experiment consistently conducted across multiple international laboratories, where blood parameters from one individual were tested on devices from either the same or different manufacturers. Theoretically, the result should be the same on different devices. However, in practice, interlaboratory discrepancies remain persistent. The question remains whether such experiments have yielded their maximum potential information. In reality, the implementation of these experiments was limited by the absence of a clear mathematical model for the processing and optimal use of such comparative measurements, as well as the lack of an organizational structure for their performance. The proposed measurement model enables the joint processing of any measurement combination of any human blood samples, certified and non-certified reference materials, manufacturers’ control samples, etc., during international and interlaboratory comparisons of measurement results. It is proposed that measurements be conducted in accordance with the Metrological Measurement Network (MMN) scheme, which has significant advantages over the circular and radial schemes. In the absence of certified reference materials (CRMs) or reference methods, it is proposed to average the reference numerical axis based on the measurement results made by a large number of working devices from all manufacturers. This will provide a local reference, relative to which the measurement biases of each device will be determined. This concept represents the core contribution of this research, for processing interlaboratory comparisons measurement results, specifically within the domain of human blood haematological parameters.
Certified reference materials (CRMs) are essential for ensuring high-quality measurements and guaranteeing their metrological traceability to the International System of Units (SI). Reliable analytical results are indispensable for consumer protection. In this context, this work conducted a feasibility study of a candidate certified reference material for lactose-free powdered milk. A small-scale batch was produced and subjected to studies of homogeneity, transportation stability, and characterization according to ISO 17034 and ISO 33405. This batch was considered sufficiently homogeneous and could be transported for up to 40 days at a temperature of up to (22 ± 2) °C without compromising the values of lactose and water content, and with no changes in its appearance. The informative value for the mass fraction of lactose was (1.06 ± 0.193) mg/g (k = 2, 95
Traceability in laboratory medicine requires use of well-characterized standards, yet accurate quantitation of intact biological macromolecules remains challenging. Peptide and protein materials are therefore most commonly first hydrolyzed to their constituent amino acids (AA), which are then quantitated by an isotope dilution (ID) approach employing AA standards. As such, the National Research Council Canada has produced two amino acid certified reference materials (CRMs) to facilitate peptide and protein quantitation traceable to the Système international d’unités (SI): ALEU-1 (certified for l-leucine purity) and APHE-1 (l-phenylalanine). Analyte mass fractions were determined via quantitative proton nuclear magnetic resonance (1H-qNMR) spectroscopy using SI-traceable internal standards. Structurally related impurities, i.e., alternative amino acids, were quantitated by an ID-standard addition approach via liquid chromatography–tandem mass spectrometry (LC-MS/MS), and relevant NMR signals were corrected accordingly. Additionally, small amounts of the d-enantiomer were detected in each CRM by chiral labeling followed by LC-MS/MS. Vial-to-vial homogeneity was established using qNMR measurements, while a combination of qNMR and LC with ultraviolet–visible spectrophotometric detection was used to evaluate transportation and long-term storage stabilities. The purity of l-leucine in ALEU-1 was 0.9935 ± 0.0054 g/g (k = 2, 95
Impurity G, also known as 3-Chloro-N,N-dimethylpropan-1-amine, is a genotoxic impurity that may be present in benzydamine hydrochloride and can cause damage to genetic material, so its content must be estimated. Development of analytical methods for quantifying impurity G in benzydamine hydrochloride is a challenge, mainly because its control is at trace levels. This work applies the concepts of analytical quality by design (AQbD), measurement uncertainty, and the green chemistry approach to determine the content of impurity G in benzydamine hydrochloride using gas chromatography coupled to the flame ionization detector (GC-FID) and liquid–liquid extraction (LLE). Initially, screening was carried out using Plackett–Burman and followed by optimization with the central composite design (CCD). Response surface methodology was used to define the method operable design region, ensuring optimal performance and the definition of robust methods. Optimized conditions included a DB-624 chromatographic column (30 m × 0.53 mm × 3 µm), direct splitless injection, a flow rate of 8.5 mL/min, and helium as the carrier gas. Sample preparation used either n-heptane (4 µL) or ethyl acetate (3 µL) as the extraction solvent. The validated methods demonstrated selectivity, linearity (2.5–6.0 ppm), precision, and accuracy. The green metrics (AGREE tool) using ethyl acetate in sample preparation were greener (0.73) than n-heptane (0.67) and the Ph. Eur. method (0.45). To demonstrate applicability under real analytical conditions, three independent API batches were analyzed, yielding impurity levels of 0, 3, and 4 ppm, thereby confirming the method’s capability for reliable quantification at trace levels. Measurement uncertainties were also evaluated, showing acceptance limits (AL) for GC-FID procedures using n-heptane and ethyl acetate as extractors of 4.25 ppm (g = 0.75) and 4.75 ppm (g = 0.25), respectively
Verifying the homogeneity of the samples used for a proficiency test is a normative requirement to ensure that the variation in the results is due to the laboratories’ analyses rather than the heterogeneity of the test material. A general method based on the assessment of between-sample and within-sample (analytical) variance components of 10 samples analyzed in duplicate according to the recommendation of the ISO 13528 standard can be strict for microbiological analyses. This paper proposes an alternative approach to evaluating sufficient sample homogeneity of a new proficiency test based on standard deviation control charts plotted for successive homogeneity and proficiency tests in previous rounds. The proposed method is based on the observed stability in the variation in colony counts at different levels of contamination in food and water microbiology proficiency tests organized by Bureau Interprofessionnel d’Études Analytiques (BIPEA). However, the control limits are adapted to different test microorganisms and matrices due to their distinctive characteristics. Examples of these control charts for the enumeration of microorganisms in water, meat, and wine over the 2017 to 2024 period are presented.
Soil contamination with petroleum hydrocarbons is a growing global concern due to its toxic components, necessitating accurate detection to assess the impact of human activities. Certified reference materials (CRMs) are an effective approach to achieve measurement accuracy and metrological traceability and are required by ISO/IEC 17025. This study developed three soil CRMs with different concentrations of petroleum hydrocarbons (C10–C40), with samples collected from distinct contaminated areas. The certified values and expanded uncertainties were 3.32 × 103 mg/kg ± 0.36 × 103 mg/kg (GBW(E)070415), 0.57 × 103 mg/kg ± 0.07 × 103 mg/kg (GBW(E)070416), and 0.42 × 103 mg/kg ± 0.06 × 103 mg/kg (GBW(E)070417), respectively. After air-drying, coarse-to-fine grinding (< 0.147 mm), homogenizing, and cobalt-60 sterilization, the materials were bottled in 100 g portions (glass bottles) and stored at a low temperature (below 0 °C). By optimizing the pretreatment conditions (extraction reagents, extraction techniques, temperature, and pressure), the quantitative accuracy and precision were improved. Gas chromatography with flame ionization detection (GC-FID) was used for certification, homogeneity, and stability assessment. Expanded uncertainties (k = 2) were evaluated based on the contributions from characterization, homogeneity, and stability. Additionally, after two years of stability monitoring, the results of the three CRMs were observed within the expected uncertainty ranges.
Castor oil (CO), a valuable natural oil derived from Ricinus communis seeds, is widely used in pharmaceuticals due to its high-ricinoleic acid content (82 to 85
There is a significant interest by reference material producers to issue digital reference material documentation. To achieve this, a structured digital representation of the relevant data must be created and made available on the World Wide Web. The National Research Council of Canada (NRC) has accomplished this by creating unique digital identifiers and using the NRC Digital Repository which has enabled machine-readable integration with other databases. We discuss our efforts and provide applications showcasing the added value of open-access FAIR data for chemical metrology. In particular, we present two proof-of-concept applications, web and mobile versions of a Reference Material Explorer software that demonstrate how digital reference material documentation enables data retrieval, dynamic searching, visualization, and integration with external databases such as PubChem.
Following the rapid and successful deployment of the mRNA-based, lipid nanoparticle-delivered COVID-19 vaccines, lipid-based drug delivery systems became integral to mainstream medicine. To support continued advancement of such systems, we developed three relevant anionic nanoparticle reference materials, which were thoroughly characterized and certified for mean particle hydrodynamic diameter with additional reference and informational values provided. The certified reference materials comprise one liposome formulation (ALIPO-1) and two distinct siRNA-loaded lipid nanoparticle formulations (ALNP-1 and LNP-2), each exhibiting a monodisperse particle population. The certified mean hydrodynamic diameter (Z-average) and the associated expanded uncertainty are, respectively, equal to (90.8 ± 1.2) nm, (123.2 ± 1.5) nm, and (68.8 ± 1.6) nm; the corresponding polydispersity index (PdI) and expanded uncertainty values are 0.054 ± 0.017, 0.041 ± 0.008, and 0.083 ± 0.020. The formulations are stored long-term at −70 °C and are projected to maintain size stability for several years. When dispersed, they also demonstrate sufficient short- to medium-term stability to support a range of biological and biomedical applications.
Clinical laboratories rely on internal quality control (QC) systems to ensure the reliability of examination results that support clinical decision-making. Conventional QC approaches, including Westgard multirule systems and Sigma-based evaluation, are effective in detecting analytical deviations but provide limited support for structured interpretation and documentation. Variability in how QC events are interpreted and recorded may affect documentation consistency and traceability within ISO 15189-aligned environments. This study evaluated a ChatGPT-5-based digital quality assistant (DQA) implemented as a supervised decision support tool for QC interpretation and documentation in clinical chemistry laboratories. A structured, two-site evaluation was conducted using examination-phase QC interpretation events (n = 1000) and documentation workflow records. Performance was assessed across four predefined objectives: interpretation agreement with expert adjudication and established rule-based approaches, documentation quality and traceability, system reproducibility and explainability, and operational workflow impact. All outputs were reviewed and verified by laboratory personnel prior to use. The DQA demonstrated higher agreement with expert-adjudicated interpretations, achieving 90.0
