EAL interlaboratory comparison Wa1 – Testing of potable water

 The accreditation of laboratories has emphasized the use of interlaboratory comparisons as a tool to monitor the comparability and accuracy of results laboratories produce. An interlaboratory comparison for water laboratories was organized among European Cooperation for Accreditation (EA) member countries; 30 laboratories, 7 of which were not accredited, from 14 European countries participated in this intercomparison. All the laboratories were chosen by the appropriate national accreditation bodies, with the instruction to select as participants those laboratories which act as national reference laboratories in this field. About 90% of the data collected was considered satisfactory after statistical treatment. Non-accredited laboratories performed as well as accredited laboratories. The laboratories were asked to take corrective action and report the corrections to the accreditation bodies. A great variation in the reported uncertainties of the results was observed. There seems to be a need to organize EA interlaboratory comparisons for national reference laboratories analysing water. It is obvious that even reference laboratories need training in how to estimate the uncertainty of results. Received: 22 July 1998 · Accepted: 21 September 1998     

Accreditation of small laboratories

 This paper presents the result of an investigation concerning which areas of EN 45001 are considered as especially problematic by small laboratories (<10 employees). The investigation was performed by distributing questionnaires to European laboratories. To be able to differentiate between areas considered as problematic only by small laboratories and areas considered as problematic by laboratories in general, some questionnaires sent in by larger (>10 employees) laboratories were used. The determination of measurement uncertainties within reasonable efforts and the requirements to take part in round robin and proficiency testing were considered problematic by laboratories of all sizes. Training is an area where small laboratories have specific problems and so are the requirements for the identification of all equipment. Other problematic areas for small laboratories are areas were there are needs for personnel, e.g. appointing supervising personnel and expenditure for internal audits. The last area to be considered as problematic is matters concerning documentation. Finally some advice concerning assessment of small laboratories is given. Received: 25 February 2000 / Accepted: 20 April 2000     

The implementation of accreditation in a chemical laboratory

This article describes the current state of the art in the accreditation of chemical laboratories, both in Europe and world-wide, emphasising the most common discussion topics. The results of recent proficiency testing in chemical laboratories are summarised to draw conclusions on the performance of accredited laboratories.     

Accreditation of pathology laboratories in Finland

 The Finnish Accreditation Service (FINAS) accredits testing laboratories in all fields including medical laboratories according to European standard EN 45001 and ISO Guide 25. At the beginning of 1998, FINAS published a recommendation on how to apply general standards in histo- and cytopathology. Four pathology laboratories have been accredited to date. FINAS has not included autopsies in these accreditations. The International Academy of Pathology (IAP)-Finnish Division has recognized 21 pathology laboratories according to standards of their own. Although accreditation by FINAS is not connected to the system of the IAP-Finnish Division, the requirements are very similar in both. Less than half of the pathology laboratories in Finland participate in national quality improvement programme or have been accredited by FINAS.     

Reliability of measurement uncertainty estimates for forensic analyses: evidence from recent proficiency tests

The ability of forensic laboratories to reliably estimate the uncertainty of their reported results is assessed by means of data from recent proficiency tests in which participants reported both their results and the associated uncertainties. Topics covered include the determination of blood alcohol, breath alcohol, and controlled substances—services commonly provided by forensic laboratories. It is seen that a statistically significant number of laboratories underestimate their own uncertainties, based on the incidence of the laboratories’ own reported coverage intervals failing to include the participant mean or assigned concentration of the test material.     

Policies and criteria on accreditation of testing laboratories in Korea

Policies and criteria for the accreditation of testing laboratories in Korea are reviewed according to the laws and regulations within the organizational framework. According to the Weights and Measures Act, the administrator of Korean Industrial Advancement Administration (KIAA) may accredit qualified testing laboratories in Korea. Criteria, procedures, and surveillance of accredited laboratories are specified in the Enforcement Regulation of the Weights and Measures Act drawn up by the Ministry of Trade, Industry, and Energy. Further detailed accreditation criteria and processes are prescribed in the Operation Guideline for the Accreditation of Testing Laboratories prepared by the KIAA. The Korean Laboratory Accreditation Scheme (KOLAS) of the KIAA is the authorized representative institution for the accreditation of testing laboratories in compliance with the ISO Guides 25/58 and the Operation Guideline for the Accreditation of Testing Laboratories. Finally, the current status of accredited laboratories in Korea is briefly described.     

Twenty-year review of laboratory performance on enteric parasitology external quality assessment surveys 1992–2011, Ontario Canada

Quality Management Program?CLaboratory Services (QMP?CLS) is a mandatory external quality assessment (EQA) and accreditation programme for laboratories in Ontario. This report summarizes performance of Ontario laboratories on QMP?CLS enteric parasitology EQA surveys and compares this performance over time. The results reported by participating laboratories were assessed against the expected results as determined by reference or referee laboratories. The number of laboratories licensed for parasitology decreased dramatically over the 20?years. On average, more than 80?% of participants and often more than 90?% were able to detect and identify the species and stages for the majority of parasites. Many of the challenges contained multiple parasites and about half contained low numbers, which affected performance on individual samples. The level of performance by Ontario laboratories on parasitology EQA surveys was consistently high over the 20?years. The parasites that presented the most difficulty were Enteromonas hominis and Trichomonas hominis.     

What Happens When Discovery Laboratories Are Integrated into the Curriculum at a Large Research University?

Traditional laboratories are often based on the hidden assumptions that students can, and indeed should, work alone, and that they can leave the laboratory when they have finished collecting the data or observations. Discovery laboratories provide an alternative to traditional laboratories in which one or more routes are taken by groups of students working toward the discovery of a specific scientific relationship or concept. The discovery laboratories used in this study were developed by colleagues from institutions where faculty teach the laboratory component of the course. The goal of this study was to see what happens when discovery laboratories are integrated into the general chemistry curriculum at a large research university where teaching assistants are in charge of the laboratory sections.For the purpose of this study, we differentiated between a minimal level of success, in which discovery laboratories become an alternative approach to traditional experiments, and a significant level of success, in which they become a preferred approach. Evidence is presented to support the notion that discovery laboratories can be successfully integrated into the curriculum at a large research university, that students in the discovery laboratories believe they had to take responsibility for what happened in the laboratory, that both teaching assistants and the students reacted positively to the discovery laboratories, and that we achieved at least our definition of the minimal level of success.     

统计质量保证技术在分析测试实验室内部质量控制中的应用

对通过统计质量保证（SQA）技术进行分析测试实验室内部质量控制（IQC）的方法作了初探。研究结果表明,SQA技术的应用能保证实验室始终处于统计受控状态,确保测试数据的有效性,有利于分析测试实验室质量保证活动的开展。     

Bacterial analysis by MALDI-TOF mass spectrometry: An inter-laboratory comparison

Bacterial analysis by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry has been demonstrated in numerous laboratories, and a few attempts have been made to compare results from different laboratories on the same organism. It has been difficult to understand the causes behind the observed differences between laboratories when different instruments, matrices, solvents, etc. are used. In order to establish this technique as a useful tool for bacterial identification, additional efforts in standardizing the methods by which MALDI mass spectra are obtained and comparisons of spectra from different instruments with different operators are needed. Presented here is an extension of our previous single-laboratory reproducibility study with three different laboratories in a controlled experiment with aliquots of the same bacterial culture, matrix stock solution, and calibrant standards. Using automated spectral collection of whole-cell bacteria and automated data processing and analysis algorithms, fingerprints from three different laboratories were constructed and compared. Nine of the ions appeared reproducibly within all three laboratories, with additional unique ions observed within each of the laboratories. An initial evaluation of the ability to use a fingerprint generated within one laboratory for bacterial identification of a sample from another laboratory is presented, and strategies for improving identification rates between laboratories is discussed.     

Monte Carlo simulation of background characteristics of low-level gamma-spectrometers

Large volume Ge detectors require efficient methods of background reduction if radionuclide analyses at very low-levels are planned. It is advisable therefore to carry out simulations of background characteristics of Ge detectors in advance of installations of low-level Ge-spectrometers either in surface or underground laboratories. We present results of Monte Carlo simulations of background characteristics of Ge detectors in surface laboratories with various lead shielding without and with anticosmic shielding, as well as in underground laboratories operating at different depths.     

Proficiency testing of animal nutrition laboratories

The Embrapa Cattle-Southeast research unit conducts a program to compare the results provided by laboratories that perform animal feed analyses. Fifty-two laboratories, representing all the Brazilian regions, have participated in the program. The assays included are those normally carried out by animal nutrition laboratories on animal feed and mineral supplements, a total of 22 different analyses. Four rounds of the program are performed annually. Each package provided to the laboratories for testing contains three kinds of animal feed (three each of forage and commercial feed), along with three mineral supplements. For the evaluation of assigned values and standard deviation, the median and robust standard deviation of the participants’ results are used. This paper reports the experience in coordinating the Brazilian interlaboratory comparison exercise.     

Macrozoobenthos interlaboratory comparison on taxonomical identification and counting of marine invertebrates in artificial sediment samples including testing various statistical methods of data evaluation

A macrozoobenthos interlaboratory comparison was carried out by 16 laboratories to check the taxonomical expertise and the precision of sorting and counting. Participating laboratories had to determine and count in an artificial sediment sample 22 selected macrozoobenthos species taken from the western Baltic Sea. Two methods for the analysis of data were applied: assessment of qualitative and quantitative successful hits and the maximum-likelihood method.The results of counting were mostly precise (one lab without mistake). Four laboratories had a rate of false determination of 10%, eight laboratories between 10 and 20% and four laboratories of more than 20%.The species Arctica islandica, Retusa obtusa, Fabricia stellaris, Polydora quadrilobata, Pholoe assimilis, Microdeutopus gryllotalpa, and Corophium crassicorne caused some problems at the species determination step.The comparison of the different methods of statistical data analysis shows that the maximum-likelihood method is more sensitive than the method of successful hits.Presented at the Eurachem PT Workshop September 2005, Portorož, Slovenia.     

The influence of a quality system according to ISO/IEC 17025 on the performance of Brazilian laboratories in proficiency testing in the environmental area

This paper presents a performance analysis of laboratories in proficiency testing (PT) with the main objective of evaluating whether having accreditation to ISO/IEC 17025 or not having an implemented quality system has an influence on the performance of these laboratories. This research was conducted with data from an accredited PT scheme of physical–chemical water analyses. Nine metals were considered in the analysis, with a total of 896 results. The performance indicator was z-score. The proposed analysis was conducted through statistical methods of analysis of variance, Dunnett’s test, Chi-square and cross-tabulation. It was verified that there is a significant difference between the performance of accredited laboratories, recognised laboratories, and laboratories that do not have an implemented quality system. It was established that an accredited or recognised quality system has a positive influence on the laboratory performance, resulting in a lower z-score (in module) and in a larger percentage of satisfactory results.     

Inter-laboratory comparisons: Determination of actinides in excreta

Inter-laboratory tests are a means of assessing the analytical coherence of medical laboratories. In radiotoxicology, this kind of exercise makes it possible to keep up with laboratory know-how and with the evolution and relative performances of analytical techniques (precision and reproducibility). However, the goal of the laboratories taking part in these annual exercises is not only to check the accuracy of their results. The analytical discussions and the chance to compare experiences enrich the group's general competence.French biologists have been organizing annual radiotoxicology intercomparison exercises since 1978. The exercises are carried out within the framework of a working group (GT1) operating under the aegis of the French Atomic Energy Commission's (CEA) Medical Coordinator. Using reports and diagrams which present the results obtained by the participants in the form of syntheses, the authors describe how the exercises for determining actinides in excreta (urine and faeces) are organized, how the results are evaluated in terms of the analytical methods used, and the improvements made in analytical and metrological performance.Up until 1985, these exercises were limited to French laboratories. Since then, the exercises have acquired an international dimension, opening up to include interested foreign radiochemists, initially from European laboratories, and now from laboratories worldwide. At the present time, 35 laboratories representing 9 countries take part regularly in these intercomparison exercises.     

APLAC interpretation and guidance on the estimation of uncertainty of measurement in testing

The Asia Pacific Laboratory Accreditation Cooperation (APLAC) is the organization representing the community of bodies that accredit testing and calibration laboratories throughout the Asia Pacific region, including China and North America. APLAC members assess the competence of laboratories and grant them accreditation. They also provide mutual recognition of the equivalence of their accreditations, which facilitates international trade and acceptance by regulators. Harmonization of accreditation requirements is therefore vital to maintaining Mutual Recognition Arrangements. APLAC establishes management and technical criteria for accreditation and publishes guidance documents for accreditation bodies and laboratories.     

Assessment of performance of laboratories in determining acrylamide in crispbread

A proficiency testing round was undertaken to assess the performance of laboratories to measure acrylamide in a sample of crispbread. Retail samples of crispbread were ground to a fine powder and after thorough mixing were packed in 40 g units for distribution. Ten samples were selected at random and analyzed in duplicate for acrylamide by liquid chromatography/mass spectrometry (LC/MS). Standard statistical tests showed that the material was homogeneous for the purposes of proficiency testing. Test samples were distributed to 55 laboratories in 16 countries in Europe, North America, Australia, and the Middle East. The results were analyzed by standard proficiency testing statistical procedures, and laboratories were awarded z-scores on the basis of their reported results. Based on a target standard deviation (sigmap value) taken from the Horwitz equation, for a robust mean value of 1.2 mg/kg acrylamide, satisfactory results (z-score within +/- 2 for those between 0.8 and 1.6 mg/kg) were obtained by 86% of the 37 laboratories that returned results. Only 1 laboratory was unsatisfactory and 4 had questionable results. About equal numbers of laboratories used gas chromatography (GC)/MS and LC/MS procedures with about 25% using MS/MS and one using GC with electron capture detection. There was no evident trend in performance or bias in results. GC/MS and LC/MS data were evenly distributed across the population of laboratories reporting results.     

EQUIP: a worldwide program to ensure the quality of urinary iodine procedures

In 2001 the Centers for Disease Control and Prevention (CDC) established a program, Ensuring the Quality of Urinary Iodine Procedures (EQUIP); to assist laboratories around the world and assess the accuracy of their urinary iodine (UI). CDC designed EQUIP to issue unknown specimens to participating laboratories three times per year. Each laboratory was asked to analyze unknown samples in duplicate on three different days. During the first five rounds of EQUIP, 41 laboratories participated, measuring unknown samples and reporting their results to CDC. CDC used these results to prepare a statistical report for the laboratories. Feedback to the laboratories provided external confirmation regarding performance. As a group, laboratory performance improved; several laboratories made considerable improvement. Several laboratories that showed no improvement have ordered new equipment or are arranging for additional training. EQUIP is a key tool used to support laboratory quality assurance in an effort to eliminate iodine deficiency disorders (IDD) in the world.

Development of a microprocessor-based electrochemical instrument interfaced to a microcomputer system for differential-pulse stripping voltammetry in different time domains

An inexpensive, compact microprocessor-based instrument for polarographic and voltammetric analysis has been developed for use in chemically hazardous laboratories, radiation laboratories or clean laboratories. This low-cost unit controls the experiment, collects the data and can be regarded as expendable. The microprocessor-based instrumentation is interface to a microcomputer system, which is external to the laboratory and has all the required peripherals associated with larger laboratory computers. In this institution, four laboratories having the inexpensive microprocessor systems are linked to the larger microcomputer which is housed in an air-conditioned room better suited for computers. A new approach to data collection and evaluation using different time domains in differential-pulse stripping voltammetry is presented as an example of the use of such instrumentation.     

Reliability of measurement results in food microbiology: the contribution of reference laboratories in the European Union and of international/European standardization

The contribution of reference laboratories in the European Union and of European/international standardization to the reliability of food microbiology measurement results is discussed. A set of European Union reference laboratories has been established. Each of them coordinates a network of national reference laboratories which, in turn, coordinate networks of laboratories in charge of official testing and sometimes own checks in each European Union country. Their contribution to the reliability of food microbiology measurement results is illustrated by three food safety cases: Listeria monocytogenes, coagulase positive staphylococci and milk/milk products. The contribution of European/international standardization focuses on two topics: method validation and measurement uncertainty. The standards covering these topics—EN ISO 16140 and ISO/TS 19036—are briefly discussed, and an update given on their ongoing revision.