Quality assurance in the microbiology laboratory

 The pertinent issues necessary for the establishment of quality assurance in the microbiology laboratory are discussed. Quality assurance is a planned system of control measures that enables management to ensure that the analytical data produced in the laboratory are valid. To introduce quality assurance, all activities in the laboratory that affect the production of analytical data must be documented and controlled. These include sampling, method selection, laboratory environment, equipment, reagents and media, staff, reference materials and internal and external quality control. Laboratory accrediation in accordance with EN45001 and ISO Guide 25 enables laboratories demonstrate to an external agency their ability to perform analytical work and produce valid analytical data. This gives creditability to the laboratory and allows management to have confidence in the data produced. Received: 6 June 1995 Accepted: 3 July 1995     

Quality assurance in the view of a commercial analytical laboratory

 The necessity for analytical quality assurance is primarily a feature of the analytical process itself. With the full establishment of the EU domestic market, it is also becoming a legal necessity for an increasing number of analytical laboratories. The requirements which laboratories will need to fulfil are stipulated in DIN EN 45 001. Accredited testing laboratories must in fact provide evidence that they work solely in accordance with this standard. National and EU commissions, which are legislative authorities, tend therefore to specify analytical methods, e.g. in the form of regulations or appendices thereto, intended to ensure that results from different laboratories will be comparable and hence will stand up in a court of law. The analytical quality assurance system (AQS), introduced by the Baden-Württemberg Ministry for the Environment in 1984, obliges laboratories to regularly participate in collaborative studies and thereby demonstrate their ability to provide suitably accurate analyses. This alone, however, does not sufficiently demonstrate the competence of a laboratory. Only personal appraisal of the laboratory by an auditor, together with the successful analysis of a sample provided by the same and performed under his observation, can provide proof of the competence of the laboratory. From an analytical point of view, the competence of a laboratory must be regarded as the decisive factor. Competence can only be attained through analytical quality assurance, which thus must be demanded of all laboratories. Received: 4 October 1996 Accepted: 15 January 1997     

Evaluating the state-of-the-practice in soil measurements in relation to environmental regulations

 The results of chemical analyses of soils show large variations due to the heterogeneity of the material, differences in pretreatment and analytical methods, and unavoidable random errors. In this article, the analytical aspects in the determination of heavy metals in soils are highlighted. Both within-laboratory and between-laboratory variation must be minimized by validation and standardization procedures, respectively, in order to keep the variations resulting from the analytical procedure at an acceptably low level. Even then, the best results will show uncertainties of 5–20%, an issue that should be recognized by governmental and legal bodies. Received: 9 November 1995 Accepted: 1 December 1995     

Trace analytical performance, epistemology and engineering creativity

Analytics is a professional and systematic compilation of instances for the inference of problem solving truths. Relevant analytical results are the starting point of inductive learning in engineering. In the semiconductor industry, diagnostic investigations must be based on both process and product monitoring using trace-analytical methods. The analyst’s strive for detection power and an increasing number of analytes are the key and flywheel of engineering knowledge. Received: 9 October 1995 / Accepted: 14 May 1996     

Key requirements for introducing quality assurance in measurement laboratories

 The implementation of a quality assurance system is fraught with difficulties. However, these difficulties may be overcome if the laboratory uses suitable means to facilitate the process. It is necessary to mobilise the intelligence and energy of all members of the laboratory. In order to command adherence, the project must be shared, and this necessitates a major effort by all concerned. Communication is a major factor in obtaining the support of all parties. Six important steps must be distinguished: – Defining quality policy – Creating awareness, information, training – Creating a quality structure – Establishing a deadline for obtaining accreditation – Progressive implementation – Experimentation and validation. Even if the task of obtaining and maintaining accreditation remains difficult, it clearly promotes a minimum level of organisation and stepwise progress in quality assurance. The laboratory must keep improving its quality system, using European Standard EN 45001 as an effective management model. Received: 9 April 1997 · Accepted: 11 September 1997     

Regulatory compliance vs. NEXUS quality for laboratory tests

In the U.S., all clinical laboratory testing is regulated by the Clinical Laboratory Improvement Amendments (CLIA) (). The CLIA link test quality and adherence to a body of testing regulations intended to ensure accurate, reliable, and timely patient test results. The goal of the CLIA legislation was to ensure a minimum, fundamental level of quality. In the context of “NEXUS,” quality must “go beyond getting the ‘right’ answer on the ‘right’ patient that can be interpreted against ‘right’ reference values. CLIA regulations with specific minimum, performance requirements, or safeguards, are designed to prevent testing errors. The US Institute of Medicine found that testing processes fail as a result of human error, lack of documentation, and lack of test management. In the latest (2004) interpretations of CLIA regulations, the minimum quality control requirement continues to be analyzing at least two external, liquid quality control materials per test per day. In 1995, we proposed that the responsibility for achieving quality test results shifts from the sole purview of the laboratory director to an “alliance” of laboratory professionals, manufacturers, and regulators. The EQC (equivalent quality control) concept as proposed is a positive step in achieving this alliance. With the obvious lack of scientific and statistical robustness, EQC falls far short of ensuring quality. Achieving the “NEXUS Vision” for quality laboratory testing will not come solely from laboratory professionals. The NEXUS is about how to ensure the full-quality assessment of the testing process – pre-analytical, analytical, and post-analytical.Presented at the 10th Conference Quality in the Spotlight, March 2005, Antwerp, Belgium.     

Experience with in-house PT-schemes in the chemical industry

There are many different means of demonstrating the quality of performance of an analytical laboratory. Proficiency testing (PT) is just one! As in other analytical fields, interlaboratory comparisons play an important role in the chemical industry. Collaborative trials or method performance studies do have a long tradition in this field. Sometimes they were designed as laboratory performance studies with the clear aim of making analytical results comparable, e.g. petrol, coal, gas, noble metals analyses – not to mention the biggest PT scheme run on a daily world-wide basis – trade itself. All this is an ongoing process, which started long before the idea of assessing and accrediting the performance of analytical laboratories was born. However, when striving for accreditation in 1996, the analytical production laboratories of the Chemicals Business Unit of the Bayer AG in Germany implemented another facet of PT schemes. In-house-PT schemes are performed regularly and turned out to be useful in evaluating, monitoring, and thus improving, the quality of routine analytical work. Received: 5 December 2000 Accepted: 15 January 2001     

Why do food analysts need quality assurance?

 Most sophisticated products require testing for compliance with specifications and safety regulations before release into many markets, and trade in many simpler commodities and products also requires supporting technical information. Test documentation has become an essential element in this trade. Food intended for human consumption certainly falls into the "sophisticated products" category. Lack of acceptance of laboratory test data across national borders may be a significant barrier to trade. In order to avoid such barriers and unnecessary duplication of laboratory tests, mutual recognition of laboratory results should be regarded as an important means of facilitating international trade in food products. It is difficult to envisage recognition of test data across borders without internationally agreed criteria for assessing the competence of testing. These criteria should, as a minimum, require that a laboratory involved in the analysis of foods operates a suitable quality system. The laboratory must create a quality system appropriate to the type, range and volume of work performed. It is necessary for the elements of this system to be documented in a quality manual which is available for use by the laboratory personnel. The quality manual must be kept up-to-date by a person or persons having responsibility for quality assurance within the laboratory. This paper describes and discusses the elements of a quality system in a food laboratory, including suitable quality assurance measures, the use of validated analytical methods and participation in proficiency testing schemes. Received: 24 February 1996 Accepted: 13 March 1996     

On practical metrology and chemical analysis: legal,institutional and technical evolutions in the Australian national measurement system

 Economic and technological change, regional and international trade and the globalisation of industry have led to intense pressures for improvements to analytical quality, reliability and comparability. Of central importance are national traceability structures connecting chemical measurements in the field with internationally accepted measurement units and their practical realisations. Australia has a developed physical and engineering measurement system, a legislative framework for analytical traceability and, in the National Association of Testing Authorities, a recognised laboratory accreditation system. The need has been identified to develop the technical capability to perform matrix-independent reference measurements for the certification of traceable reference materials, useable as practical analytical etalons to establish metrological control systems in field measurements for amounts of substance. Recently, a unique collaborative consortium has proposed a National Analytical Reference Laboratory (NARL). The NARL is designed to be a metrological mass spectrometry facility for the transference of measurement units to more widely useable chemical measurement standards and reference materials. Received: 10 October 1995 Accepted: 26 October 1995     

A review of autovalidation software in laboratory medicine

Although autovalidation procedures have been around for many years, through the use of computers and the application of (medical) protocols, they are now becoming part of the production environment of medical laboratories. The introduction of high volume instruments within routine medical laboratory testing certainly speeded up their application as well. After defining autovalidation, autoverification and autoconfirmation, this paper provides a framework for the different ways and places where these tools can be applied within laboratory medicine. Technology as well as organization are essential building blocks to reach well-defined, transparent and assured quality. A laboratory automation system (LAS) brings both areas together in a logical, future-oriented way. Strengthening the information loop, reaching guaranteed quality (analytical, turnaround times and efficiency), leads towards strict management of the laboratory processes. This includes all laboratory processes and here autovalidation and autoreporting become essential. A survey of currently available software routines and their appraisal from a managerial viewpoint are given. It can be concluded that autovalidation software in laboratory medicine is maturing and is rapidly becoming a critical success factor in any medical laboratory. Quality can be automated for sure and autovalidation software will prove to be a valuable aid to do so. Received: 23 August 2002 Accepted: 26 August 2002 Presented at the European Conference on Quality in the Spotlight in Medical Laboratories, 7–9 October 2001, Antwerp, Belgium     

Multivariate data analysis of quality parameters in drinking water

The quality of water destined for human consumption has been treated as a multivariate property. Since most of the quality parameters are obtained by applying analytical methods, the routine analytical laboratory (responsible for the accuracy of analytical data) has been treated as a process system for water quality estimation. Multivariate tools, based on principal component analysis (PCA) and partial least squares (PLS) regression, are used in the present paper to: (i) study the main factors of the latent data structure and (ii) characterize the water samples and the analytical methods in terms of multivariate quality control (MQC). Such tools could warn of both possible health risks related to anomalous sample composition and failures in the analytical methods.     

Validation of an analytical method to determine trace metal impurities in fluoride compounds by flame atomic absorption spectroscopy

 The development of an analytical method for the determination of some heavy metals (Fe, Cu, Co, Zn and Ni) in fluoride compounds [Cu(BF₄)₂, Sn(BF₄)₂, Pb(BF₄)₂ and HBF₄] by flame atomic absorption spectroscopy is described. This method is to be used as a routine analytical method in an industrial quality control laboratory. To this end the "performance characteristics" of an instrumental analytical method such as matrix effects, sensitivity, linearity, detection and quantitation limits, precision and accuracy were evaluated for every system under study. The results of these investigations showed that non-spectral interferences (due to the presence of large concentrations of major metals such as Cu, Sn and Pb) were observed. Nevertheless it was possible to define a matrix concentration interval where matrix effects were not statistically significant, and therefore a direct calibration approach could be used as the calibration tool whenever the major metal concentration was not higher than 40×10^–3 kg l^–1. A guide to the developement of an analytical method for trace metal determination is provided. General tools for quality control have been used in order to show how an analytical method can be tested daily and evaluated in a convenient manner. Received: 29 January 1997 Accepted: 11 March 1997     

ISO compliant laboratory quality systems and incident monitoring improve the implementation of laboratory information systems

Quality systems can provide a means of measuring the rate of occurrence of defined incidents and non-conformities. We have studied the application of laboratory quality systems to monitoring the implementation of laboratory information systems (LIS) in two similar size tertiary hospital pathology laboratories in Australia. At one site, one department implemented a quality system accredited to ISO 9001–1987 and ISO 9001–1994 while the rest of the organisation did not have a formal quality system; this site implemented the Cerner PathNet LIS. At the other site, the organisation was in the process of implementing ISO/IEC Guide 25–1990 and ISO/IEC 17025–1999; this site implemented the PJACC AUSLAB LIS. The rate of quality system incidents and non-conformities was used to track the progress of implementation of the LIS. We found that different quality systems appeared equally useful in monitoring the rate of occurrence of incidents. However, the presence of a formal quality system greatly improved the proportion of incidents that could be investigated and resolved at root cause level. Incident monitoring, as part of a formal quality system, proved to be a useful tool in monitoring and managing the implementation of these LIS. Received: 4 August 2001 Accepted: 21 March 2002     

Proficiency testing in analytical laboratories: how to make it work

 This paper covers the role of proficiency testing schemes in providing an occasional but objective means of assessing and documenting the reliability of the data produced by a laboratory, and in encouraging the production of data that are "fit-for-purpose". A number of aspects of proficiency testing are examined in order to highlight features critical for their successful implementation. Aspects that are considered are: accreditation, the economics and scope of proficiency testing schemes, methods of scoring, assigned values, the target value of standard deviation σ_p, the homogeneity of the distributed material, proficiency testing in relation to other quality assurance measures and whether proficiency testing is effective. Stress is placed on the importance of any proficiency testing scheme adhering to a protocol that is recognised, preferably internationally. It is also important that the results from the scheme are transparent to both participating laboratory and its "customer". Received: 03 November 1995 Accepted: 20 November 1995     

Combinatorial chemistry

Rapid progress in molecular biology and the resulting ability to determine the activity of new compounds extremely efficiently have led to an enormously increased demand for test substances which cannot be satisfied by conventional synthesis methods. Combinatorial chemistry is a method that enables the efficient generation of large numbers of structurally diverse products. These products can be obtained as single compounds or in the form of defined mixtures. The synthesis is performed according to combinatorial principles (“produce all possible combinations of the reactants used”). The techniques and methods applied in combinatorial synthesis give rise to analytical problems: monitoring of reactions that take place on solid supports, structure elucidation with only minute amounts of material available or the characterization of substance mixtures. Examples from the authors’ laboratory illustrate how some of these problems can be approached. Received: 26 October 1996 / Revised: 24 February 1997 / Accepted: 26 February 1997     

Combinatorial chemistry

Rapid progress in molecular biology and the resulting ability to determine the activity of new compounds extremely efficiently have led to an enormously increased demand for test substances which cannot be satisfied by conventional synthesis methods. Combinatorial chemistry is a method that enables the efficient generation of large numbers of structurally diverse products. These products can be obtained as single compounds or in the form of defined mixtures. The synthesis is performed according to combinatorial principles (“produce all possible combinations of the reactants used”). The techniques and methods applied in combinatorial synthesis give rise to analytical problems: monitoring of reactions that take place on solid supports, structure elucidation with only minute amounts of material available or the characterization of substance mixtures. Examples from the authors’ laboratory illustrate how some of these problems can be approached. Received: 26 October 1996 / Revised: 24 February 1997 / Accepted: 26 February 1997     

Different approaches to legal requirements on validation of test methods for official control of foodstuffs and of veterinary drug residues and element contaminants in the EC

 In order to ensure food consumer protection as well as to avoid barriers to trade and unnecessary duplications of laboratory tests and to gain mutual recognition of results of analyses, the quality of laboratories and test results has to be guaranteed. For this purpose, the EC Council and the Commission have introducedprovisions – on measures for quality assurance for official laboratories concerning the analyses of foodstuffs on the one hand and animals and fresh meat on the other, – on the validation of test methods to obtain results of sufficient accuracy. This article deals with legal requirements in the European Union on basic principles of laboratory quality assurance for official notification to the EC Commission and on method validation concerning official laboratories. Widespread discussions and activities on measurement uncertainty are in progress, and the European validation standards for official purposes may serve as a basis for world-wide efforts on quality harmonization of analytical results. Although much time has already been spent, definitions and requirements have to be revised and further additions have to be made.     

External quality assessment schemes for clinical laboratories

 The clinical routine laboratory generally utilizes cheap, easy and rapid measurement procedures ("methods") in order to meet the requirement for the production of many analytical results (500–3000 per day) of hundreds of different types. The measurement procedures are optimized for the analysis of native patients' samples, but are frequently sensitive to deviation of the composition of the matrix from that in normal fresh samples. The inherent lack of stability of patient samples means that control samples need to be stabilized. The method of stabilization is critical. Furthermore, the method of "spiking" samples with pathological material is a matter of concern. Generally, minimally processed patients' samples should be used in external quality assessment (EQA) schemes. Consensus values are currently the most popular for use as a guide to the best results from participating laboratories in EQA schemes; these often work fairly well. However, the uncertainty and traceability of this type of value is unknown, and in some cases may even be misleading, tending to preserve bad routine methods when these are dominant in the participating laboratories. Reference measurement procedure (RMP) values are recommended to provide scientifically based information, to facilitate the proper choice of methods in the routine laboratories, and to validate the suitability of control materials in EQA schemes. The present paper provides selected examples from a study comparing consensus values with RMP values on lyophilized sera, and also presents results on a fresh frozen thawed serum for the study of commutability. Received: 8 November 1995 Accepted: 8 May 1996     

Quality assurance in forensic toxicological analysis

 In this paper, we review the work done in forensic toxicological analysis during about the last 30 years in Europe and to some extent in other parts of the world to assure the quality of toxicological investigations. Guidelines for carrying out toxicological analyses set up by professional bodies in the United States (AAFS/SOFT), Europe (GTFCh) and worldwide (TIAFT) are mentioned, and the problems of complying with the regulations set up in EN 45 000/ISO 9000 are discussed in detail. There are still diverging opinions as to whether toxicological laboratories should comply with good laboratory practice or with EN 45 000, and, as fas as Germany, Switzerland and Austria are concerned, a working group of the GTFCh is discussing which procedure should be adopted. Apart from having this discussion, the group aims to standardize suitable methods and is planning the organization of suitable round robins. Received: 18 December 1995 Accepted: 11 April 1996