National Institute of Standards and Technology, NIST

Analysis of Standards The analysis of a standard containing a known concentration of analyte also can be used to monitor a system s state of statistical control. Ideally, a standard reference material (SRM) should be used, provided that the matrix of the SRM is similar to that of the samples being analyzed. A variety of appropriate SRMs are available from the National Institute of Standards and Technology (NIST). If a suitable SRM is not available, then an independently prepared synthetic sample can be used if it is prepared from reagents of known purity. At a minimum, a standardization of the method is verified by periodically analyzing one of the calibration standards. In all cases, the analyte s experimentally determined concentration in the standard must fall within predetermined limits if the system is to be considered under statistical control. 

There are no estabHshed specifications for the standard reference samples used in general chemical analysis. Many such substances, however, are analyzed and certified by the National Institute of Standards and Technology (NIST), formerly the National Bureau of Standards (NBS). Specific reference standards are required for many of the analyses included in the USP and NE standards for dmgs. 

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. 

NIST Update High Tech PubUshiag Co. NewsNet news and information on activities of the U.S. National Institute of Standards and Technology (NIST)... 

Physical or artifactual standards are used for comparison, caUbration, etc, eg, the national standards of mass, length, and time maintained by the National Institute of Standards and Technology (NIST) or the standard reference materials (SRMs) collected and distributed by NIST. Choice of the standard is determined by the property it is supposed to define, its ease of measurement, its stabiUty with time, and other factors (see Fine chemicals). 

Currently, there are about 197,500 entries in the National Institute of Standards and Technology (NIST) Crystal Data File. An exhaustive search takes about one minute. Unit cell parameters are very definitive. Usually only one or a few hits are found and the appropriate Hterature reference(s) are Hsted. If no hits are found, the stmcture has not been previously reported. 

Calibration Cahbration entails the adjustment of a measurement device so that the value from the measurement device agrees with the value from a standard. The International Standards Organization (ISO) has developed a number of standards specifically directed to cahbration of measurement devices. Furthermore, compliance with the ISO 9000 standards requires that the working standard used to cahbrate a measurement device must be traceable to an internationally recognized standard such as those maintained by the National Institute of Standards and Technology (NIST). 

The National Institute of Standards and Technology (NIST) released certified standard materials of a baby food composite (SRM 2383) and an infant formula (SRM 1846) containing carotenoids however, the relative uncertainties of certified values are considerably high, ranging Irom 20% for P-carotene (cis + trans) to 28% for lutein (including esters) and to a 47% for free lutein reference value in SRM 2383. ... 

The National Institute of Standards and Technology (NIST) molten salts database has been designed to provide engineers and scientists with rapid access to critically evaluated data for inorganic salts in the molten state. Properties include density, viscosity, electrical conductance, and surface tension. Properties for approximately 320 single salts and 4000 multicomponent systems are included, the latter being primarily binary. Data have been abstracted from the literature over the period 1890-1990. The primary data sources are the National Bureau of Standards-National... 

In 1901, the U.S. National Bureau of Standards (NBS) - now the National Institute of Standards and Technology (NIST) - was founded because of the increasing demand for various kinds of standards in the rapidly developing engineering industries. The early history of the NBS reference material program started in 1905 with a cooperative effort within the iron and steel industry whereby industrial analysts helped characterize the individual reference materials. Cooperation with NBS was recognized as a mark of achievement for the laboratory, so this effort served a dual purpose. It both helped the laboratory develop its measurement skills and also helped NIST understand the meastuement problems associated with a given matrix. 

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. 

As part of maintenance, some equipment may need to be calibrated. SOPs must include calibration methods, and a report format needs to be available at the time of calibration. Calibration SOPs must include pass/fail specifications as well as corrective actions to be taken in the event of calibration failure. For quality calibration standards use National Institute of Standards and Technology (NIST) traceable standards or other intrinsic standards of known purity, quality, and stability. These standards should have certificates attesting to their performance properties. After calibration, the metrologist or other responsible person should review the calibration reports to identify any issues with the equipment that may need further attention. 

Accuracy of in vivo and in vitro measurements of americium is determined through the use of standard, certified radioactive sources with known concentrations of americium. The primary source of certified americium standards is the National Institute of Standards and Technology (NIST). Standard solutions are available for241 Am (SRM 4322, 40 Bq/g [1.1 nCi/g]) and 243Am (SRM 4332, 40 Bq/g [1.1 nCi/g]). Standard Reference Materials for human lung (SRM 4351) and human liver (SRM 4352) are also available from NIST. 

Science cannot be performed without an accurate system of measurement, which is globally standardized and compulsory. Units and standards of measurement are agreed upon and harmonized on an international basis by the Bureau International des Poids et Mesures in Sevres, France, and by the International Organization for Standardization in Geneva, Switzerland. The units and standards are then laid down in national laws. Nearly all countries have accepted the Systeme International d Unites (SI units) as their system of measurement. This also applies to countries that had been accustomed to use British units like Australia, Canada, South Africa and the United States. In Britain, SI units are official from January 2010. The valid standards are available from the competent bureaus, for example Bureau International des Poids et Mesures, www.bip.fr National Measurement Institute (Australia), www.measurement.gov.au National Institute of Standards and Technology (NIST, USA), www.physics.nist.gov/ Pubs/SP811/... 

Techniques have been developed for the quantification of fire propagation using FMRC s Small-Scale Flammability Apparatus (A,6) and the National Institute of Standards and Technology (NIST) Flame Spread Apparatus (j J ). In this study, the FMRC technique was used. Oxygen Index and its dependency on temperature was used by AMTL to examine the fire propagation behavior of small samples of FRC materials (J 2). 

Becker, D., Christensen, R., Currie, L., Diamondstone, B., Eberhardt, K. R., Gills, T., Hertz, H., Klouda, G., Moody, J., Parris, R., Schaffer, R., Steel, E., Taylor, J., Watters, R. and Zeisler, R., Use of NIST Standard Reference Materials for Decisions on Performance of Analytical Chemical Methods and Laboratories, NIST Special Publication 829, National Institute of Standards and Technology (NIST), Gaithersburg, MD, USA, 1992. 

Some reference material producers/suppliers use different names to describe their materials. For example, a Standard Reference Material (SRM) is a certified reference material issued by the National Institute of Standards and Technology (NIST), while European Reference Materials (ERMs) are CRMs produced under a joint collaboration between three European reference materials producers, i.e. BAM (Federal Institute for Materials Research and Testing, Germany), IRMM (European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, Belgium) and LGC (UK). 

National Institute of Standards and Technology. NIST Chemistry WebBook NIST Standard Reference Database Number 69. June 2005 Release, http //webbook.nist.gov/chemistry/. 2005. 

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