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Accreditation and Quality Assurance: Journal for Quality, Comparability and Reliability in Chemical Measurement (v.2, #5)
Assessing reliability in measurement: a matter of assessing procedures or of assessing results?
by Paul De Bièvre (pp. 215-215).
Quality assurance in forensic science: the UK situation by Terry Antony Gough (pp. 216-223).
The contribution to the debate on the quality of forensic science in the UK by various bodies including government, professional and accreditation organisations, is discussed. The practical steps that have been taken over many years to improve quality and to ensure that there are well-documented systems in place are considered. These include laboratory quality systems, proficiency testing and the training of forensic scientists.
Keywords: Key words Forensic science; Accreditation; Certification; Professional competence; Academic and vocational qualifications
How to achieve world-wide mutual recognition of calibration and test results – or: Who accredits the accreditor? by Klaus Brinkmann (pp. 224-233).
The ongoing globalization of the economy demands cost- and time-effective conformity assessment procedures through mutual cross-border recognition of calibration and test results. Accreditation is an important tool to ensure the technical competence of laboratories performing calibrations and tests. The question, however, arises as to which mechanisms should be applied to achieve technical equivalence of accreditations throughout the world as a basis for mutual recognition of agreements. To avoid third party "accreditation of accreditors", accreditation bodies have established a specific procedure of regional technical cooperation in order to create a climate of confidence resulting in formal mutual recognition agreements. Key elements of this cooperation are the harmonization of operation procedures in addition to existing international standards, a continuos programme of interlaboratory comparisons, and an extensive procedure for mutual peer assessments. The present article provides detailed information on such cooperation within the European region as an example, describes the present situation with respect to mutual recognition agreements within Europe, and gives a brief look into the future with respect to inter-regional cooperation.
Keywords: Key words Accreditation; Mutual recognition agreements; Peer assessment; Interlaboratory comparisons
Validation of a computer program for atomic absorption analysis by I. Kuselman; Boris Anisimov; Avinoam Shenhar; Alex Lepek (pp. 234-237).
The approach to validation of a computer program for an analytical instrument as a component of the analytical method (using this instrument with the program) is discussed. This approach was used for validating a new program for atomic absorption analysis. The validation plan derived from this approach was based on minimising the influence of all steps of the analytical procedure on the analytical results obtained by the method. In this way significant changes in the results may be caused only by replacement of the previous program by the new one. The positive validation conclusion was based on the comparison of the results of the analysis of suitable reference materials obtained with the new program and with its precursor in the same conditions, and also on comparison of their deviations from the accepted reference values for these materials, with the corresponding uncertainties.
Keywords: Key words Validation; Computer program; Analytical instrument; Measurement uncertainty; Atomic absorption analysis
Robustness testing of control charts employed by analytical laboratories by O. Mestek; Jiří Pavlík; Miloslav Suchánek (pp. 238-242).
The robustness of Shewhart control charts for subgroup means and subgroup ranges was tested by using the Monte Carlo method using training data sets comprising various numbers of points, with two repetitions in each subgroup (as in routine laboratory practice). The following control chart designs were tested: conventional based on the arithmetic mean and standard deviation, robust based on the median and/or the trimmed mean and Winsorized standard deviation, and a two-step design. The methods were applied to the system in the state of statistical control (outliers excluded) and to the system without statistical control (outliers included). Satisfactory results for both cases were only obtained when using the two-stage control charts. The conventional charts led to underestimation of the effect of outliers in the system without statistical control, whereas the robust control charts led to overestimation of the effect of outliers (false alarm) in the system under statistical control. The tests also gave evidence that the training set should include 20 points as a minimum.
Keywords: Key words Control charts; Robust statistic; Monte Carlo simulation
Reference materials for large-scale metal deposition surveys by Eiliv Steinnes; Åke Rühling; Harri Lippo; Ahti Mäkinen (pp. 243-249).
In order to ensure quality assurance in large-scale environmental contamination studies involving many different analytical laboratories, the use of calibrated reference materials is essential. Prior to a survey of atmospheric metal deposition in 1995 comprising 20 countries and covering large parts of Europe, the lack of suitable reference materials of moss and organic-rich soil was apparent. In order to improve the quality of analytical data to be produced in this international survey, candidate analytical laboratories were invited to participate in an intercomparison exercise. Three moss and three soil humus reference samples specifically prepared for this purpose were distributed anonymously among the laboratories, which were asked to report data for ten priority elements (V, Cr, Fe, Ni, Cu, Zn, As, Cd, Hg, Pb) and as many additional elements as they determined normally. In this paper the analytical data from the intercomparison are evaluated, and recommended values for the ten priority elements and 17 additional elements (B, Na, Mg, Al, S, K, Ca, Mn, Co, Se, Rb, Sr, Sb, Cs, Ba, La, Th) in each of the six reference samples are established. These samples should be useful for similar future studies including areas where the contamination levels are very low.
Keywords: Key words Analytical quality control; Reference materials; Moss; Organic surface soil; Intercalibration
The influence of experience on the quality of chemical measurements made on soils from former gasworks by S. D. Jones; S. Paul Blundell; Agnès M. A. Bodin (pp. 250-257).
A strategy for ensuring that measurements of ten common contaminants found in soils from former gasworks are of optimum quality over long timescales is described. In particular, the performance of laboratories in applying validated measurement methods in both small- and large-scale inter-laboratory trials over a 5-year period is assessed. It is shown that a production engineering concept, the experience curve, has a significant influence on the quality of some of the measurements made and that this concept can be used to model the performance of laboratories. Complexity of the measurement procedure and familiarity of analysts with the measurement operations are suggested as the main drivers of method error. The implications of the achievable quality of measurement on the costs of land re-development and on confidence in the quality of the rejuvenated land are discussed.
Keywords: Key words Quality and reliability; Soil analysis; Experience curves; Competency testing; Manufactured gas plant
Problematic of the selection and use of certified reference materials for calibration of chemical analyses – General guidance
by Alain Marschal (pp. 259-261).
The Slovak National Accreditation System by J. Garaj; L'ubomir Šutek; Marian Weidlich (pp. 261-262).
After the split of the Czechoslovak Federation, the Slovak National Accreditation System was established in November 1993, being the only system in this country executing accreditation and certification. This system is strictly based on EN 45 000 and covers testing laboratories from both the mandatory and voluntary areas of metrological laboratories, products testing and certification, quality systems, and good laboratory practice. It seeks to reach the level of compatibility accepted and recognized by EU member countries. The development and basic features of the Slovak National Accreditation System, its basic principles, and the structure and competence of accreditation bodies are described in this article.
Keywords: Key words Accreditation system; Slovak National Accreditation System (SNAS); Accreditation bodies; Personnel
The need for quality assurance in analytical research and development
by K. Cammann; W. Kleiböhmer (pp. 262-263).
The revision of EN 45001 and ISO/IEC Guide 25 by Peter J. H. A. M. van de Leemput (pp. 263-264).
At present ISO/IEC Guide 25 and EN 45001 are under revision. This paper describes this process of the revision including the history. Also, the main differences between the officially published drafts and the current documents are pointed out.