Reference materials biological standard

International Organization for Standardization, 2004. ISO 10993-12. Biological Evaluation of Medical Devices—Part 12 Sample Preparation and Reference Materials. British Standards Institution, London. 

National Institute of Standards and Technology (NIST). The NIST is the source of many of the standards used in chemical and physical analyses in the United States and throughout the world. The standards prepared and distributed by the NIST are used to caUbrate measurement systems and to provide a central basis for uniformity and accuracy of measurement. At present, over 1200 Standard Reference Materials (SRMs) are available and are described by the NIST (15). Included are many steels, nonferrous alloys, high purity metals, primary standards for use in volumetric analysis, microchemical standards, clinical laboratory standards, biological material certified for trace elements, environmental standards, trace element standards, ion-activity standards (for pH and ion-selective electrodes), freezing and melting point standards, colorimetry standards, optical standards, radioactivity standards, particle-size standards, and density standards. Certificates are issued with the standard reference materials showing values for the parameters that have been determined. 

NAA is a quantitative method. Quantification can be performed by comparison to standards or by computation from basic principles (parametric analysis). A certified reference material specifically for trace impurities in silicon is not currently available. Since neutron and y rays are penetrating radiations (free from absorption problems, such as those found in X-ray fluorescence), matrix matching between the sample and the comparator standard is not critical. Biological trace impurities standards (e.g., the National Institute of Standards and Technology Standard Rference Material, SRM 1572 Citrus Leaves) can be used as reference materials. For the parametric analysis many instrumental fiictors, such as the neutron flux density and the efficiency of the detector, must be well known. The activation equation can be used to determine concentrations ... 

Stoepplbr M and Zeisler R, eds. (1993) Biological environmental specimen banking. A collection of papers presented at the ist International Symposium on Biological Environmental Specimen Banking. Vienna, Austria, 22-25 September 1991. Sci Total Environ, Vols. 139 and 140. Tanner JT (1984) The FDA-IFC infant formula methods study and standards for organic nutrients. In Wolf WR, ed. Biological Reference Materials, pp 197-205. John Wiley Sons. 

Tu Shu-Db, Lieser KH (1984) Homogeneity test of Chinese biological standard reference materials by means of instrumental neutron activation analysis, f Radioanal Nucl Chem Articles 84 301-306. 

Byrne AR, Deemelj M, Kosta L, and Tusek-Znidaric M (1984) Radiochemical neutron activation analysis in standardization of trace elements in biological reference materials at the nanogram level. Mikrochim Acta [Wien] 1 119-126. 

De Goeij JJM, VorKERS KJ, Tjioe PS, and Kroon JJ (1978) NBS SRM 1569 Brewer s yeast Is it an adequate standard reference material for testing chromium determination in biological materials. Radiochem Radioanal Letters 35 139-146. 

Gladney ES (1980) Elemental concentrations in NBS biological materials and environmental standard reference materials. Anal Chim Acta 118 385-396. 

Gladney ES, O Malley BT, Roeiandts I, and Gills TE (1987,1993 update) Standard Reference Materials Compilation of Elemental Concentration Data for NBS Chemical, Biological Geological and Environmental SRMs. NBS Spec Pub 260-111, NIST, Gaithersburg, MD. 

Taylor A (1996) Reference materials and analytical standards to stimulate improved laboratory performance Experience from the external quality assessment scheme for trace elements in biological samples. Mikrochim Acta 123 251-260. 

In Tables 6.3 and 6.4 RMs of three major producers are mentioned, i.e. the World Health Organization (WHO, International Standards), BCR (European Union, CRMs) and the National Institute of Standards and Technology (NIST, USA, SRMs). Some important national producers of clinical reference materials are the Chemicals and Inspection Testing Institute (CITI, Japan), National Institute for Biological Standards and Control (NIBSC, UK), and Deutsche Gesellschaft fiir Klinische Chemie (DGKC). There are numerous commercial producers of secondary reference materials. 

Institut de Recherches de la Siderurgie, France International Organization for Standardization ISO Council Committee on Reference Materials International Union for Pure and Applied Chemistry Laboratory of the Government Chemist, UK, formerly NPL National Bureau of Standards, USA, now NIST National Committee for Clinical Laboratory Standards, USA National Institute for Biological Standards and Control, UK Japanese National Institute for Environmental Studies National Institute of Occup. Health, Oslo, Norway National Institute of Standards and Technology, USA, formerly NBS,... 

A wide range of high quality, non-certified carotenoid and chlorophyll chemical standards are commercially available (e.g., Sigma-Aldrich, DHI, and Roth). The availability of a mixed pigment reference standard and biological matrix reference materials would improve analytical performance in individual laboratories, facilitate method and laboratory in-... 

Denise LeBlanc is the Group Leader for the Marine Sciences Group and the Manager of the Certified Reference Materials Program at the Institute for Marine Biosciences (IMB) of the National Research Council of Canada. The Certified Reference Materials Program manufactures instrument calibration standards and certified reference materials for shellfish toxins, PCBs, PACs, and trace elements in marine sediments, in biological tissues, and in seawater. Her experience resides in the manufacture and long-term production of reference materials. 

Some of the methods commonly used for the determination of thorium in biological materials are given in Table 6-1. The colorimetric methods are not capable of isotope-specific determination of thorium isotopes. Alpha spectrometric and neutron activation analysis are useful in the quantification of isotope-specific thorium and thorium-232, respectively, and have better sensitivities than colorimetric methods. Alpha spectrometry is the commonly used isotope-specific analysis for the determination of thorium-232 and the thorium-230 derived from the decay of uranium-238 (Wrenn et al. 1981). Standard reference materials (SRMs) containing thorium in human liver (SRM-4352) and human lung (SRM-4351) necessary for the determination of absolute recovery in a given sample are available from the National Institute of Standards and Technology (Inn 1987). 

More research is needed on the accurate measurement of boron in biological materials when the concentrations are <1.0 mg B/kg (Sullivan and Culver 1998). Standard biological reference materials with low boron levels need to be produced for use in interlaboratory comparisons. This becomes especially important in studies on boron-deficiency states and the ability of the organism to conserve boron at very low intakes (Sullivan and Culver 1998). More research is needed on homeostatic regulation of boron and functional markers of boron metabolism (Sutherland et al. 1998). Sullivan and Culver (1998) recommend additional studies to establish ... 

The certification procedure for seven trace metals (Ba, Ca, Li, Mg, Mn, Na and Sr) in the certified reference material FEBS-1 (National Research Council Canada, Institute for National Measurement Standards, Ottawa, Canada) based on fish otolith matrix by isotope dilution - ICP-MS in comparison to ICP optical emission spectrometry and X-ray fluorescence analysis, is described by Sturgeon et al4X The isotope dilution technique is also employed for species analysis in biological systems,46 e.g., for the determination of mercury species in tuna material,54 or in aquatic systems using cold vapour ICP-MS.55... 

An analytical procedure has been proposed for precise uranium isotope ratio measurements in a thin uranium layer on a biological surface by LA-ICP-MS using a cooled laser ablation chamber.125 One drop of uranium isotope standard reference materials NIST, 350, NIST 930, of our isotopic laboratory standard CCLU 500 (20p.l, U concentration 200 ng 1) and of uranium with natural isotopic pattern were deposited on the leaf surface and analyzed by LA-ICP-MS at well defined laser crater diameters of 10, 15, 25 and 50 p.m. A precision for measurements of isotope ratios in the range of 2.1-1.0% for 235U/238U in selected isotope standards was observed whereby the precision and the accuracy of isotope ratios compared to the non-cooled laser ablation chamber was improved.125... 

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