Forgot your password?
New user?
New Window Opens on the Secret Life of Microbes: Scientists Develop First Microbial Profiles of Ecosystems
CAS announces the release of SciFinder Scholar for Mac OS X
Press Releases
Press Releases
| Check out our New Publishers' Select for Free Articles |
Accreditation and Quality Assurance: Journal for Quality, Comparability and Reliability in Chemical Measurement (v.6, #12)
Special issues planned on reliability of measurements in food science and clinical chemistry
by Paul De Bièvre (pp. 487-487).
Metrological role of neutron activation analysis. IA. Inherent characteristics of relative INAA as a primary ratio method of measurement by Tian Weizhi; Ni Bangfa; Wang Pingsheng; Cao Lei; Zhang Yangmei (pp. 488-492).
In a series of three papers, the inherent characteristics of relative instrumental neutron activation analysis (INAA) as a primary ratio method of measurement, the unique functions of parametric INAA as an ideal back-up method of the relative INAA, and the valuable role of INAA in characterization of sampling behavior of individual elements in certified reference materials (CRMs) will be discussed. In this paper, the first of the series, the uncertainty evaluation and the traceability of values measured by neutron activation analysis (NAA), especially instrumental NAA (INAA), will be described to demonstrate the method at its ”the state-of-the-art” level can meet CCQM criteria for a primary ratio method. The scope and examples will be given.
Keywords: Keywords Instrumental neutron activation analysis; Primary ratio method; Uncertainty; Traceability
A model to set measurement quality objectives and to establish measurement uncertainty expectations in analytical chemistry laboratories using ASTM proficiency test data by Dean A. Flinchbaugh; L. F. Crawford; David Bradley (pp. 493-500).
A model is presented that correlates historical proficiency test data as the log of interlaboratory standard deviations versus the log of analyte concentrations, independent of analyte (measurand) or matrix. Analytical chemistry laboratories can use this model to set their internal measurement quality objectives and to apply the uncertainty budget process to assign the maximum allowable variation in each major step in their bias-free measurement systems. Laboratories that are compliant with this model are able to pass future proficiency tests and demonstrate competence to laboratory clients and ISO 17025 accreditation bodies. Electronic supplementary material to this paper can be obtained by using the Springer LINK server located at http://dx.doi.org/ 10.1007/s007690100398-y.
Keywords: Keywords Proficiency test; Uncertainty; Measurement quality objectives; Accreditation; ISO 17025
Verification of chemical measuring instruments in China by Zhao Min (pp. 501-506).
The metrological properties of chemical measuring instruments directly and critically effect the accuracy of results. In order to achieve accurate and reliable measuring results, measuring instruments should be verified . This paper introduces some verification schemes and verification regulations of chemical measuring instruments in China.
Keywords: Keywords Verification; Verification regulation; Measuring instruments
Establishment of SI-traceable reference values for the content of various elements in the IMEP-14 sediment sample by I. Papadakis; E. Vendelbo; L. Van Nevel; P. D. P. Taylor (pp. 507-513).
For the first time in the International Measurement Evaluation Programme (IMEP)-14, a sediment sample was offered to analytical laboratories to perform measurements of As, Cd, Cr, Cu, Fe, Pb, Hg, Ni, U and Zn. In line with IMEP policy, the results were presented according to the certified / assigned reference values established by several reference laboratories around the world. The certification campaign is described in detail. Isotope dilution mass spectrometry was applied as a primary method of measurement, whenever possible, to achieve SI-traceable results. For reference measurements of As, Fe, Hg and Zn, k0-neutron activation analysis and Zeeman atomic absorption spectrometry were applied. The reference values (ranges) were characterised as ”certified” (for Cd, Cr, Pb, Ni and U) or ”assigned” (for As, Cu, Fe, Hg and Zn) according to IMEP policy. The measurement uncertainty of the certified / assured reference values was calculated according to the ISO/BIPM Guide.
Keywords: Keywords IMEP; Reference values; Certification; Uncertainty calculation; Metals in sediment; Interlaboratory comparison
Performance tests and internal quality control activities for the routine analytical use of composite electrodes by Matilde Luque; A. Ríos; Miguel Valcárcel (pp. 514-520).
The use of a solid electrode in routine analytical work is proposed as a good alternative for electroanalytical detection. The performance of the electrode for oxidative voltammetry was studied for the model compound, catechol. Some theoretical aspects of the preparation and features of the PVC-graphite composite electrode are shown. A protocol has been described for its construction and general advice for the appropriate use. Quality control activities were designed to check the performance of the electrode.
Keywords: Keywords Performance test; Internal quality control; Routine analytical work
The ILAC Arrangement – Part I by P. S. Unger (pp. 521-522).
As of August 2001, 38 laboratory accreditation bodies of the International Laboratory Accreditation Cooperation (ILAC) have signed the multi-lateral, mutual recognition arrangement (the ”ILAC Arrangement”) to promote the acceptance of accredited test and calibration data. This Arrangement provides significant technical underpinning to international trade. Until now, there has been no international mutual recognition agreement in laboratory accreditation, which has been a hindrance for some types of international trade. The key to the Arrangement is the developing global network of accredited testing and calibration laboratories that are assessed and recognised as being competent by ILAC Arrangement signatory accreditation bodies. The signatories have, in turn, been peer-reviewed and shown to meet ILAC’s criteria for competence. Now that the ILAC Arrangement is in place, governments can take advantage of it to further develop or enhance trade agreements. The ultimate aim is increased use and acceptance by industry, as well as government, of the results from accredited laboratories, including results from laboratories in other countries. In this way, the free-trade goal of ”a product tested once and accepted everywhere” can be realised.
Selectivity – the hallmark of an analytical chemist: the current situation in the analytical sciences by Jörgen Vessman (pp. 522-527).
In the scientific analytical chemical literature there is a problem in that there is a mix up of the two terms ”selectivity” and ”specificity” as indicators of the degree of interferences in analytical methods. This article gives an overview of the situation in the field of analytical sciences and ends with some recommendations in favour of using the term ”selectivity” only.
Keywords: Keywords Analytical chemistry; Interferences; Selectivity; Specificity; Terminology
B. Neidhart and W. Wegscheider (eds) Quality in chemical measurements – Training concepts and teaching materials
by Angel Rios (pp. 532-532).