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Accreditation and Quality Assurance: Journal for Quality, Comparability and Reliability in Chemical Measurement (v.3, #10)
Global comparability of analytical results by Adolf Zschunke (pp. 393-397).
Global decisions made on the basis of chemical analytical results need global comparability. The concept of traceability is important and necessary but not sufficient to achieve global comparability, especially for routine analysis in environmental protection, health care and public safety. Sometimes comparability is only determined by the method. In this case validated methods have to be known and recognized internationally. In addition, a minimum level of proficiency of the personnel producing analytical results has to be guaranteed. Finally, a system of measures designed to build up trust is needed for worldwide acceptance of analytical results. The method of self-declaration by the supplier of chemical analytical services has the advantage of presenting specific responsibility and gaining a good reputation. Additional methods should be employed. The evaluation of reference materials by specific quality criteria is mentioned as an example.
Keywords: Key words Traceability; Reference materials; Method validation; Proficiency testing; Reliability
New tools: Uncertainty-based data evaluation by W. Bremser (pp. 398-402).
The principles of uncertainty-based data evaluation are explained. Based on a brief review of recent publications on the topic, examples for application to standard procedures in analytical chemistry – calibration, method validation, standard addition etc., – are given. The performance and the advantages of uncertainty-based data evaluation are discussed.
Keywords: Key words Uncertainty; Calibration; Weighted regression; Uncertainty propagation; Variances; Covariances
Need for quality management in research and development by Karl Cammann; W. Kleiböhmer (pp. 403-405).
There is growing interest in setting up a general concept for quality management and quality control in research and development, which in this case means, for example, research in the fields of medicine and social sciences. This article is a strong plea for a quality management system in all fields of research and development and will probably initiate broad discussion on this delicate topic.
Keywords: Key words Quality management; Research; Development; Scientific fraud
Consideration of the uncertainty in the CRM value with the analysis of solid materials using atomic spectrometry by U. Kurfürst (pp. 406-411).
The principles of the ISO "Guide to the expression of uncertainty in measurement" are applied to the analysis of solid materials by graphite furnace atomic absorption spectrometry. Assessment of trueness is achieved by the analysis of a certified reference material (CRM) under fixed instrumental conditions. For the evaluation of the method's uncertainty (as part of the validation) a model equation is derived, considering all significant contributions, including the uncertainty in the CRM value and the uncertainty in the CRM analysis. A concrete example is presented and discussed (soya flour as an unknown sample and CRM BCR rye grass). For routine analysis a pooled estimate from the validation experiment can be used, leading to an acceptable small uncertainty range even in the case of "duplicate determination". The test for trueness (acceptance) of the result of the CRM analysis is applied and the correction for detected bias is discussed.
Keywords: Key words Uncertainty; Atomic spectrometry; Certified reference material; Method validation; Trueness
Is the estimation of measurement uncertainty a viable alternative to validation? by S. Küppers (pp. 412-415).
Two examples of the use of measurement uncertainty in a development environment are presented and compared to the use of validation. It is concluded that measurement uncertainty is a good alternative to validation for chemical processes in the development stage. Some advantages of measurement uncertainty are described. The major advantages are that the estimations of measurement uncertainty are very efficient, and can be performed before analysis of the samples. The results of measurement uncertainty influence the type of analysis employed in the development process, and the measurement design can be adjusted to the need of the process.
Keywords: Key words Chemical analysis; Development process; Measurement uncertainty; Validation; Practical examples
Accreditation and authorization in environmental analysis by W. Jäger; Kirsten Gerlach (pp. 416-418).
Since 1989 testing laboratories in Europe have had the possibility to confirm their competence in carrying out certain testing procedures by means of accreditation. Over the years an independent European Accreditation system has been developed, which many member states of the European Union have joined. The existing accreditation organizations joined to form the unified organization EA (European Cooperation for Accreditation) in 1997. Members of this organization are, inter alia, one representative of the accreditation authorities of each of the member states. The German accreditation system is different to the European system in that it is split. Here, we differentiate between the sector established by law and that which is not. Both sectors, however, pursue the same goal. Because of this double certification of competence and the resulting multiple reviews, German testing laboratories face a considerably greater load in comparison to their European colleagues. Several authorities are already working on the removal of this split accreditation system. The efforts must, however, be concentrated and brought into line. Efforts by the DAP and DACH for flexible accreditation and the creation of a standardized registration authority for testing laboratories in the field of workplace measures are examples of how the German accreditation system could develop in the future.
Keywords: Key words Accreditation; Competence; Recognition; DIN EN 45001
Measurement uncertainty procedures revisited: Direct determination of uncertainty and bias handling by W. Hässelbarth (pp. 418-422).
This article is based on a lecture presented at the Analytica Conference, where the basic principles for evaluating and expressing the uncertainty of analytical measurements, as set out in the guides published by ISO and EURACHEM, were reviewed, and the inventory of procedures and tools for effective implementation of these principles was examined. While the emphasis in the lecture was on basic principles, this article presents a more detailed elaboration of one of the main practical procedures outlined in the lecture: direct determination of uncertainty and handling of bias.
Keywords: Key words Uncertainty; Traceability; Validation; Bias handling
The new ISO 17025 – basic idea by Herfried Kohl (pp. 422-425).
This paper offers a concise overview of the recent draft of ISO 17025, which is expected to replace EN 45001 in 1999. Reference is made to the general area of related ISO standards for management systems. The main changes compared with EN 45001 are discussed for testing laboratories.
Keywords: Key words ISO 17025; Quality assurance; Quality management; Laboratory management
Quality management and third-party assessment in medical institutions: international experience
by Inger Cecilie Laake; Arve Thendrup; L. Halbo (pp. 427-428).