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Accreditation and Quality Assurance: Journal for Quality, Comparability and Reliability in Chemical Measurement (v.3, #1)
Qualification and validation of software and computer systems in laboratories by L. Huber (pp. 2-5).
When software and computer systems are purchased from vendors, the user is still responsible for the overall validation. Because the development validation can only be done by the developers, the user can delegate this part to the vendor. The user's firm should have a vendor qualification program in place to check for this. The type of qualification depends very much on the type and complexity of software and can go from documented evidence of ISO 9001 or equivalent certification for off-the-shelf products to direct audit for software that has been developed on a contract basis. Using a variety of practical examples, the article will help to find the optimal qualification procedure.
Keywords: Key words Validation; Qualification; Vendors; Computers; Analytical laboratories
Measurement uncertainty and its implications for collaborative study method validation and method performance parameters by S. L. R. Ellison; Alex Williams (pp. 6-10).
ISO principles of measurement uncertainty estimation are compared with protocols for method development and validation by collaborative trial and concomitant "top-down" estimation of uncertainty. It is shown that there is substantial commonality between the two procedures. In particular, both require a careful consideration and study of the main effects on the result. Most of the information required to evaluate measurement uncertainty is therefore gathered during the method development and validation process. However, the information is not generally published in sufficient detail at present; recommendations are accordingly made for future reporting of the data.
Key requirements for introducing quality assurance in measurement laboratories by L. Mouillet (pp. 11-13).
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.
Keywords: Key words Quality assurance; Accreditation; Measurement laboratories; Management model
A view of uncertainty at the bench analytical level by A. Ríos; Miguel Valcárcel (pp. 14-19).
The problem with which analytical laboratories are confronted, after traceability of their results has been demonstrated, is correctly estimating their uncertainty– to which traceability is also to some extent subject. While the general principles for calculating the uncertainty of physical measurements are applicable to chemical metrology, some refinements are needed, especially careful selection and planning the level at which uncertainty will be estimated by each laboratory in accordance with its capacity and required demands. Depending on the particular decision to be made, the mechanism to be used to estimate the uncertainty varies markedly; also, the rigour of the estimation increases with increasing stringency of the demands. This paper describes the primary sources of uncertainty in chemical metrology and discusses different approaches to its estimation in relation to the type of analytical laboratory concerned. The view presented tries to be close to the bench analytical level, in order to be practical and flexible for laboratories, although it could sometimes be considered slightly heterodox.
Keywords: Key words Uncertainty; Quality Assurance; Chemical measurements; Metrology
A practitioner's approach to the assessment of the quality of sampling, sample preparation, and subsampling by Adriaan Marten Heine van der Veen; Anton Alink (pp. 20-26).
The methodology of evaluating the performance of sampling, sample preparation, and subsampling is reviewed. The requirements to be set for a successful experiment are revisited. The central role of the reference method is explained, and so is the choice of the parameters and the measurement methods. Based on the principles of the "Guide to the expression of uncertainty in measurement" (GUM), a statistical model is developed that demonstrates the influence of the experimental design on the outcome of the assessment experiment. This relationship is often overlooked in practice, as it is hardly mentioned in written standards dealing with this kind of quality assessments. The statistical framework thus developed covers the statistical procedures commonly appearing in written standards. Finally, the issue of testing the significance of the bias obtained from the experiment is discussed.
Keywords: Key words Sampling; Quality assessment; Statistical modelling; Uncertainty
The scope of accreditation and consideration of methods and criteria for the assessment of the scope
(pp. 27-29).
Methods validation: AOAC's three validation systems by M. Lauwaars (pp. 32-35).
Validated methods of analysis are needed for many purposes: enforcement of regulations, import/export control, in accredited laboratories, academia, institutions. The AOAC INTERNATIONAL Official Methods Program is designed to provide fully validated methods of analysis, based on interlaboratory testing by a minimum of eight laboratories. Another, lesser validation system is used for peer-verified methods of analysis where two or three laboratories participate. The system for performance testing of test kits is specially designed for a thorough testing of manufacturer claims, and can be obtained by submitting a kit to Performance Testing by the AOAC Research Institute.
Keywords: Key words Validation of methods of analysis; Interlaboratory study; Peer-verified methods; Performance testing of test kits
Workshop on QC/QA organized by EURACHEM- Russia at the Inter- national Congress on Analytical Chemistry, Moscow, June 15–21, 1997
by Gregory I. Ramendik (pp. 36-37).