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Accreditation and Quality Assurance: Journal for Quality, Comparability and Reliability in Chemical Measurement (v.5, #2)
Trade Relations 1999 between the EU and the USA: News from “The New [1995] Transatlantic Agenda”
(pp. A74-A74).
Report on the EUROLAB/EURACHEM Workshop on Quality Assurance of Computer Systems in Laboratories at the Federal Institute for Materials Research and Testing (BAM)
by M. Golze (pp. B74-75).
The multilateral recognition arrangement between National Measurement Institutes (NMI) is signed at BIPM
(pp. 43-43).
QA and QM in R & D and non-routine analysis for industrial chemistry
by Zbigniew Dobkowski (pp. 44-46).
The evaluation of measurement uncertainty from method validation studies by Vicki J. Barwick; Stephen L. R. Ellison (pp. 47-53).
A protocol has been developed illustrating the link between validation experiments, such as precision, trueness and ruggedness testing, and measurement uncertainty evaluation. By planning validation experiments with uncertainty estimation in mind, uncertainty budgets can be obtained from validation data with little additional effort. The main stages in the uncertainty estimation process are described, and the use of trueness and ruggedness studies is discussed in detail. The practical application of the protocol will be illustrated in Part 2, with reference to a method for the determination of three markers (CI solvent red 24, quinizarin and CI solvent yellow 124) in fuel oil samples.
Keywords: Key words Measurement uncertainty; Method validation; Precision; Trueness; Ruggedness testing
A practical analytical quality report on the effect of carotenemia on neonatal bilirubin levels by Diler Aslan; Filiz Kuralay; Tijen Tanyalcin; Orcan Tanyalcin (pp. 54-57).
The effect of haematocrit and β-carotene levels on the serum total bilirubin measurement in two analytical methods was studied as an example of the impact of practical analytical quality in medical decision making. The precision characteristics of the two methods were very similar. Based upon the significant difference in the correlation coefficient in a method comparison study before and after 20% trimming of the data, an interference effect study was performed. Haemoglobin (expressed as haematocrit) and β-carotene were the substances studied to explain the observed differences. The bilirubin test results from the Wako bilirubinometer were easily affected (n=19;X(S): 13.83±2.43;t=–6.17;P=0.000) and more elevated than in the Vitros dry chemistry systems (n=18;X(S): 12.72±2.21;t=–2.48;P=0.017), due to the presence of β-carotene (>200 μg/dl).
Keywords: Key words Analytical interference; Analytical quality; Analytical quality indicator
Uncertainties of mercury determinations in biological materials using an atomic absorption spectrometer – AMA 254 by Vaclav Synek; Pavel Subrt; Josef Marecek (pp. 58-66).
The method is based on catalysed ignition of a sample portion in a flow of oxygen, capture of mercury by an amalgamator and measurement of the mercury vapour's absorbance after thermic release from the amalgamator. Three powdered food samples, a certified reference material (CRM) human hair and a reference material (RM) urine (liquid) were measured in the first range of the instrument (the possible contents determined according to our measurement procedure were 0.0003–0.5 ppm). The calibration function used was a line passing through the origin. The combined standard uncertainties of the mercury determinations were computed from uncertainty components of five quantities: absorbance of the sample, absorbance of the sample blank, slope of the calibration line, correction factor of the abscissa axis, and mass or volume of the sample. The most important uncertainty component is the uncertainty of the sample absorbance measurement which amounts to 52% of the determination uncertainty at the minimum (RM urine) and about 90% at the maximum (in our laboratory homogenized powdered food samples; analysis of variance showed their homogeneity to be insufficient). The results of the CRM and RM analyses do not indicate a significant systematic error for this determination. The relative expanded uncertainty (coefficient was 2) of the determination increases from 9 to 13% for the insufficiently homogenized samples with decreasing mercury content (range of 0.004–0.03 ppm); higher homogeneity of samples results in a decrease of the expanded uncertainty, e.g. 4.6% for the liquid sample (RM urine).
Keywords: Key words Uncertainty in measurement; Electrothermal atomic absorption spectrometry; Mercury determination; Sample heterogeneity; Calibration line errors
International Measurement Evaluation Programme (IMEP) – Balkan Information Meeting
by I. Papadakis; A. Voulgaropoulos (pp. 75-76).
Alphabetical index of defined terms and where they can be found¶Part II: G–Q by David Holcombe (pp. 77-82).
This paper, the second of a series of three, presents the second part of an alphabetical index of approximately 1400 terms taken from various international official standards, protocols and guides. The terms listed are those encountered in the analytical sector, related to sampling, quality, conformity assessment, standardisation, measurement and related statistics. The definitions themselves are not included. The purpose of the index is to provide the user with a ready means of establishing whether a particular term has an official definition and if so where it is located. In doing so it makes location of officially defined terms more straightforward and so encourages their use. It also highlights those terms which are defined in several places, indicating the degree of equivalence between the definitions from the different sources. This second part of the index covers G–Q.
Keywords: Key words Index; Official definitions; Terms; Terminology