Centre for Standards

The PJ.P. assay requires the use of lyophilized, viable M. Ivieus ATCC 4698 cells. This substrate is available at the Centre for Standards as a ElJVcon trolled reference product. It should be stored at -20 and used within a year. 

The activity of die unknown sample is expressed relative to the standard, whidi has a well-defined activity, assigned by collaborative assay and based on kinetic analysis. The stability of the standard is guaranteed by die Centre for Standards. Sensitivity of substrate batches and spectrophotometer variation are not allowed form an absolute type of assay or unit definition. 

F.I.P. following a title means that the European Pharmacopoeia has not published a monograph concerning this enzyme. Standards and further information on such enzymes can be obtained from the Centre for Standards F.I.P., Harelbekestraat 72, B-9000 Ghent, Belgium (Telephone [+32)9 264 80 47 Telefax [+32)9 264 81 89). 

European Commission, Joint Research Centre, Institute for Reference Materials and Measurements (Belgium) International Organization for Standardization International Union of Pure and Applied Chemistry liquid chromatography... 

Certified value bSO, reference soils from Canada Centre for Mineral and Energy Technology NBS National Bureau of Standards, USA IAEA International Atomic Energy Agency, Vienna, Austria... 

It was mentioned in Section II.B that the ionization of benzoic acids is not regarded as an entirely satisfactory standard process, since in the case of —R substituents, such as OMe, it is subject to some slight effect of cross-conjugation (see structure 16). Consideration of insulated series , not subject to this effect, e.g. the ionization of phenylacetic acids, is used as the basis of the cr° scale. For the sake of uniformity cr° values for +R substituents have also been based on such systems. Wepster and colleagues124,125, however, have criticized the use of systems in which the substituent is insulated by methylene groups from the reaction centre for its tendency to lead to slightly exalted values of cr° for +R substituents, i.e. the supposed insulation is not 100% effective. They see an analogy to the very pronounced exaltations that occur in the effects of +R substituents on the... 

Accuracy, Precision, and Detection Limits — Analytical cost, accuracy, precision, and detection limits are the four main evaluation criteria for selecting an analytical method. Detection limit information will not be givdn here, as it is easily obtained from the literature or from instrument manufacturers. The analysis of NBS orchard leaves and bovine liver is often used to demonstrate the accuracy and precision of ICP analysis. We feel that the analysis of United States Geological Survey (USGS) and Canadian Centre for Mineral Energy Technology (CANMET) standard rocks, is a more rigorous test of ICP analytical accuracy because of the resistance to sample... 

Aust. J. Soil Res. 16 215-227 Joint Committee on Powder Diffraction Standards Mineral powder diffraction fde. Data book. Published by the JCPDS International Centre for Diffraction Data, Swarfhmore, Pennsylvania, U SA, pp. 942 Jolivet, J.P. Tronc, E. (1988) Interfadal electron transfer in colloidal spinel iron oxide. Conversion of Fe304 to y- Fe203 in aqueous medium. J. Colloid Interface Sci. 125 688—... 

A series of four standard soils, which are certified reference materials from the Canada Centre for Mineral and Energy Technology, Ottawa, was analyzed by the AAS/fusion procedure to assure that it gave satisfactory results. Excellent agreement with recommended values was obtained. Intercalibration of the two laboratories used for the source materials analyses was accomplished by the parallel analyses of K. Again, excellent agreement was achieved. 

Bureau of Product Standards Laboratory Accreditation Scheme Polish Centre for Accreditation Romanian Accreditation Association... 

The book collates the many standard methods, comments on their virtues and defects and considers procedures needed for both quality control and the generation of design data. The content owes much to the experience gained due to Rapra s position over many decades as an international centre for rubber research, as a test house with a history of developing test procedures and making a very significant contribution to national and international standardisation. The literature relating to the development and application of rubber test methods has also been reviewed. 

X-ray powder diffraction files (PDFs) for explosive materials are available as subsets of PDF libraries, such as Xpowder and that of the International Centre for Diffraction Data (ICDD). Commercial X-ray diffractometers can yield lattice spacings, d, to a precision of 0.0001 A. At this accuracy, it is not difficult to distinguish uniquely between many thousands of chemical compounds. Hence, XRD is a standard analytical technique for precisely identifying crystalline materials. 

Mighell, A. D. and Stalick, J. K. (1983). Crystal data. Determinative tables. Vol. 6, 3rd edn. U. S. National Institute of Science and Technology, JCPDS—Joint Committee on Powder Diffraction Standards, ICDD—International Centre for Diffraction Data. [14]... 

The Comprehensive Nuclear-Test-Ban Treaty consists of a preamble, 17 articles, two annexes and a Protocol. The Protocol describes verification procedures and contains two annexes. One annex lists the 337 facilities comprising the International Monitoring System (IMS) and the other annex describes parameters for standard event screening by the International Data Centre (IDC). 

Joint Committee on Powder Diffraction Standards. Mineral powder dif action file. Int. Centre for Diffraction Data, 1601 Park Lane, Swarthmore, Pennsylvania 19081, USA, 1168 pp. 

Release 2002. The International Centre for Diffraction Data (http //www.icdd.com). Release 1997. National Institute of Standards and Technology (http //www.nist.gov/ srd/nist3.htm). Distributed by ICDD. 

Calibration is by NBS (122, 123, 127) and three laboratory standards that have been calibrated at the Scottish Universities Research Reactor Centre (SURRC). Standards range from 5 S -17.3 to +20.3%o. This wide range permits analysis of samples with wide variations in a single suite. On pyrite, required sample weights are 1.0-1.2 mg on pyrrhotite 1.6-1.8 mg. The average 5 S reproducibility of the standards is better than 0.1 %o, and around 0.15%o for sulphide mineral samples. 

The structure of the definitions of the clinical activities has been incorporated within the national standards for classification in health in Australia. SHPA collaborated with the Australia National Centre for Classification in Health (NCCH) to develop pharmacy procedure codes within the International Statistical Classification of Diseases and Health Related Problems Australian Modification.The classification has subsequently been piloted in 28 hospitals to develop a standard approach to the documentation of clinical services to individual patients. - ... 

Identification of crystalline substance and crystalline phases in a specimen is achieved by comparing the specimen diffraction spectrum with spectra of known crystalline substances. X-ray diffraction data from a known substance are recorded as a powder diffractionfile (PDF). Most PDFs are obtained with CuKa radiation. Standard diffraction data have been published by the International Centre for Diffraction Data (ICDD), and they are updated and expanded from time to time. For one crystalline substance, there may be more than one file. The most recently updated file is recommended for phase identification. The early PDFs may contain errors in data obtained experimentally. More recently published PDFs are either obtained by more accurate experimental measurements or by theoretical calculation. A specimen to be identified should be in a powder form for most accurate matching. When we need to identify the crystal structure of a specimen that cannot be prepared as powder, matches of peak positions and relative intensities might be less than perfect. In this case, other information about the specimen such as chemical composition should be used to make a judgment. 

The report of the WHO Collaborating Centre for Chemical Reference Substances for 2004 was presented to the Committee. The Committee noted that a number of International Chemical Reference Substances (ICRS) were distributed in 2004. The most frequently requested material was the new reference standard for artesunate (Annex 1). 

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