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Accreditation and Quality Assurance: Journal for Quality, Comparability and Reliability in Chemical Measurement (v.2, #4)
Protocols for traceability in chemical analysis by P. de Bièvre; Robert Kaarls; H. Steffen Peiser; Stanley D. Rasberry; William P. Reed (pp. 168-179).
The authors propose definitions and terminology for protocols on traceability links, generally to the international system of units, for specific chemical-analytical measurements in accordance with recognized principles of science. These definitions and terms could be useful in science, technology, commerce or law. A chain of such links leads from a measurand in a sample up to a unit in the International System of Units or, if unavailable, to a value on an internationally recognized measurement scale. The quality of such a chain is quantified by combining all recognized uncertainties estimated for all its links. These uncertainties of the measured values arise from many potential error sources. The protocols should give details of specific uses of reference materials, measuring instruments and standard measurement methods.
Uncertainty in chemical analysis and validation of the analytical method: acid value determination in oils by I. Kuselman; Avinoam Shenhar (pp. 180-185).
Quantifying uncertainty in chemical analysis, according to EURACHEM document (1995), is based on known relationships between parameters of the analytical procedure and corresponding results of the analysis. This deterministic concept is different from the cybernetic approach to analytical method validation, where the whole analytical procedure is a "black box". In the latter case, analytical results only are the basis for statistical characterization of the method without any direct relationship with intermediate measurement results like weighings, volumes, instrument readings, or other parameters like molecular masses. This difference requires the harmonization of parameters to be validated and to be included in the uncertainty calculation. As an example, results of the uncertainty calculation and validation are discussed for a new method of acid value determination in oils by pH measurement without titration.
Keywords: Key words Uncertainty of measurements; Analytical method validation; Acid value determination; Oils; pH measurement
Some practical aspects of the validation of photometric systems for clinical analyses by M. Buzoianu; H. Y. Aboul-Enein (pp. 186-192).
It is well known that erroneous data reported to a physician may strongly affect medical decision making. For routine clinical chemistry purposes, different instrumentation can be used to compare measurements of unknown samples with standard reference materials. Currently, acceptable limits of accuracy and precision are poorly defined in the field of clinical chemistry laboratories. In this article, problems associated with spectrophotometric measurements, both manual and automated, are discussed. The task of the validation of photometric systems for clinical analyses is currently of considerable interest. Some practical aspects of this validation and the use of reference materials for this activity in the national area are discussed.
Keywords: Key words Traceability; Quality; Measurement; uncertainty; Clinical reference; materials; Clinical photometric; system
Traceability in the amount-of-substance analysis of natural potassium, thorium and uranium by the method of passive gamma-ray spectrometry by Y. Nir-El (pp. 193-198).
This paper describes the amount-of-substance analysis of the long-lived naturally occurring radionuclides 40K, 232Th, 235U and 238U by the method of non-destructive passive gamma-ray spectrometry. Calibrands used were standard reference materials and high-purity analytical grade chemicals. Traceability of the measured results to reference materials was established. The emission probabilities of several high-energy gamma-rays were determined. High-energy gammas were measured to decrease the effect of gamma self-attenuation.
Keywords: Key words Traceability; Amount-of-substance; Gamma spectrometry; Reference; materials; Gamma emission probabilities
Quality assurance in the view of a commercial analytical laboratory by W. Jäger (pp. 199-202).
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.
Keywords: Key words Quality assurance; EURACHEM; Analytical testing laboratory; Quality criteria; Accreditation
The European Eco-Management and Audit Scheme Accreditation – an overview by T. Dempsey; John Hussey (pp. 205-208).
Environmental quality is still deteriorating in the EU and worldwide despite all the Directives and Regulations in this field over the past 20 years. The European Community has devised a new approach to this problem with the introduction of the Eco-Management and Audit Scheme Regulation. This Regulation provides industry with an opportunity to demonstrate that it can achieve continuous improvement in its environmental performance through a voluntary scheme which is not based on the traditional command and control mechanisms of Directives. This paper gives an overview of the steps involved in implementing the European Eco-Management and Audit Scheme and the role of accreditation in supporting the scheme.
Keywords: Key words Environmental management; schemes; Verification; Accreditation