US National Institute of Standards and Technolog

US NIST (1991) Certificate of Analysis. SRM 1648 Urban Particulate Matter. US National Institute of Standards and Technology, Gaithersburg, August 30,1991. 

Tl, Xe and °Y). The US National Institute of Standards and Technology (NIST) operates an external quality control program on a varying schedule from one year to the next (Golas 1998). Details of the current program are available from the NIST website. 

The author wishes to thank Suzanne W. Slayden for her numerous scientific and editorial comments on this study, and to the Chemical Science and Technology Laboratory of the US National Institute of Standards and Technology for partial support of his research. 

CHASE, M. W. 1998. NIST-JANAF Thermochemical Tables, 4th edn. J. Phys. Chem. Ref. Data, Monograph 9, 1-1951. Cited in US National Institute of Standards and Technology (NIST) Webbook, http //webbook.nist.gov. 

The results of the second interlaboratory study of PCN analytical methods using environmental matrices, undertaken by the US National Institute of Standards and Technology (NIST), should provide an indication of the comparability of published environmental PCN data and show where additional method enhancements are needed. Further method development efforts in the analysis of PCNs, and other complex mixtures are likely to focus on improving efficiencies by optimizing run times and separation. Examples may include time-of-flight mass spectrometry and multidimensional GC. New methods, such as isotope ratio mass spectrometry, may contribute to further source apportionment of complex mixtures [88]. 

Of additional benefit to enantioselective POP separations is the quantification of enantiomer compositions in standardized reference materials, available from sources such as the US National Institute of Standards and Technology (NIST) and Environment Canada [105, 106]. Such materials are intended for quality assurance/quality control in sample processing and instrumental analysis of their respective matrices, and enantiomer quantification extends this use to enantioselective studies. 

From the US National Institute of Standards and Technology http //www.nist.gov/ pml/data/star/index.cfm (accessed 4.05.11). 

Certified reference materials (CRMs) with certified values for Al available at the time of preparation of this review from the Institute for Reference Materials and Measurements, European Community Joint Research Centre were ground water, an aquatic plant, olive leaves, beech leaves, pine needles, lichen and titanium (http // www.irmm.jrc.be). Non-Al-certified materials available were coals, river sediment, seawater, zinc and zinc alloys and titanium alloy. CRMs with certified values for Al were available from the US National Institute of Standards and Technology (http // www.nist.gov/) for days, coal, coal fly-ash, glasses, limestone, lubricating oil, a met-allo-organic Al, oyster tissue, pine needles, plant leaves, rice and wheat flours and zinc-Al alloys. Bone meal, bovine liver and muscle powder, a milk powder, and urine with non-certified Al values were available. 

Analytical chemistry uses many specialized terms that may be new to you. The definitions of the terms, usually shown in boldface, must be learned. The units used in this text are, for the most part, the units of the Systdme International d Unitds (SI system). The SI system is used around the world by scientists and engineers. The tables inside the textbook covers give the primary units of measurement in the SI system. A comprehensive list of SI units, Sl-derived units and definitions, as well as non-SI units may be found at the US National Institute of Standards and Technology (NIST) website at http //physics.nist.gov. 

Table 19.2 contains the results of niacin determinations performed in MRM mode for some grain-based food materials, including appropriate reference materials, and compares them to expected levels. For the commercial food materials, expected values are as listed on the packaging. The US National Institute of Standards and Technology (NIST) does not provide a reference value for niacin for RM 8437 however, there have been determinations of its niacin value reported in the literature (LaCroix et al. 1999 Tanner et al. 1988). The expected value for RM25C, an in-house reference material used by an analytical testing and consulting laboratory, was provided by the producer. 

The instrument is calibrated with high purity acetanilide (analytical-reagent grade reference material, US National Institute of Standards and Technology or equivalent). Acetanilide is used, because its elemental composition matches the elemental composition of particulate material obtained from seawater, i.e., C N = 8. The acetanilide is dried in a desiccator. Approximately 200 pg are weighed in a tin boat to the nearest 0.1 pg by means of a microelectrobalance. The tin boat is pelletized and analysed imder the same conditions as a sample. At least ten standards are analysed. 

JANAF = Joint Army Navy Air Force, a useful tabulation of thermodynamic data published by the (US) National Institute of Standards and Technology (see http //webbooks.nist.gov/chemistry). 

While the Beilstein file contains a good deal of data in this area, there are also excellent compilations dedicated to thermodynamic quantities. DETHERM is produced by Dechema, and contains thermophysical properties for ca. 17000 compounds and mixtures (see Chemical Engineering Databases). The subject matter is taken from phase equilibria, PVT behavior, thermodynamic quantities, transport phenomena, surface properties, and electrolyte properties. Attention must also be drawn to the compilations of the US National Institute of Standards and Technology (NIST). The NIST Chemistry WebBook contains thermodynamic data for over 5000 compounds and ion energetics data for over 10000 compounds. The user may search on specific compounds based on name, chemical formula, or CAS Registry Number. Structures are given for all species, as well as common and commercial names. 

CAS = Chemical Abstracts Service CT = connection table GFDB = Gmelin Factual Database ICSD = Inorganic Crystal Structure Database MF = molecular formula NIST = US National Institute of Standards and Technology STN = Scientific and Technological Network. 

US National Institute of Standards and Technology (NIST) that can be utilized to obtain IMFP, EAL, and MED data for particular purposes and that are useful for other AES and XPS applications [7]. We then provide information on other data and software resources available for AES and XPS. 

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