Reference standards for

Specifications for hGH products are defined by the governmental licensing authorities, eg, the U.S. Pood and Dmg Administration. Draft monographs for hGH have been prepared by both the EnitedStates Pharmacopia and the European Pharmacopeia commissions and should be formally adopted by 1995. These specifications are suitable for biosynthetic hGH. The much less purified pituitary-derived hGH has virtually disappeared from commercial production. An international reference standard for pituitary-derived hGH (lot 80/505) has been used for caUbration, particularly for bioassay purposes. A highly purified biosynthetic hGH standard (lot 88/624) has been prepared and should be formally adopted by 1995, or before. 

The American Association of Cereal Chemists has made avaUable a certified food grade wheat bran as a reference standard for research purposes. This bran is a blend of soft white wheat (87.3%) and club white wheat (12.7%). 

Class M For use as reference standards, for work of the highest precision, and where a high degree of constancy over a period of time is required. 

It appears then that the establishment of practicable and accurate reference methods presents one of the major problems in the determination of moisture in foods. The present paper summarizes some of the important factors that govern the accuracy of moisture determinations in general, and reviews some of the recently published attempts to develop methods that might serve as useful reference standards for dehydrated foods, and especially for dehydrated vegetables and fruits. 

A 12.60% NC was used as the reference standard for all samples of this material TNT and HMX were compared against pure samples of each other, respectively... 

In Table 2, results are given comparing the three above FNAA techniques for total nitrogen and corresponding HMX content of three synthetic Octol samples containing 70, 60 and 80% HMX respectively. Chemical analysis by extraction is also included as another basis for comparison. An 80/20 Octol (80% HMX) was used as the reference standard for the activation assays... 

G. J. Janz, J. Phys. Chem. Ref Data 9 (1980) 791 Molten Salts Data as Reference Standards for Density, Surface Tension, viscosity and Electrical Conductance KN03 and NaCl, American Chemical Society-American Institute of Physics-National Bureau of Standards, Washington, DC, 1980. 

Optical microscope asbestos reference standards for use in identifying and quantifying asbestos types are available both from NIST and the Institute of Occupational Medicine flOM) in Edinburgh, Scotland. The lOM materials consists of various asbestos materials actinolite, amosite, anthophyUite, chrysotile (both from Cassiar, Canada and Zimbabwe), crocidolite and tremoUte. 

Fig. 3.16 Schematic drawing of the MIMOS II Mossbauer spectrometer. The position of the loudspeaker type velocity transducer to which both the reference and main Co/Rh sources are attached is shown. The room temperature transmission spectrum for a prototype internal reference standard shows the peaks corresponding to hematite (a-Fe203), a-Fe, and magnetite (Fe304). The internal reference standards for MIMOS II flight units are hematite, magnetite, and metallic iron. The backscatter spectrum for magnetite (from the external CCT (Compositional Calibration Target) on the rover) is also shown...

SMOW Acronym for Standard Mean Ocean Water, used as a chemical and isotopic reference standard, for example, when studying oxygen isotope ratios. soap A cleaning agent made by the reaction of an oil or fat with an alkali such as soda. 

Taylor CR. Quantifiable internal reference standards for immunohistochemistry the measurement of quantity by weight. Appl. Immunohistochem. Mol. Morphol. 2006 14 253-259. 

R.J. Soulen, R.B. Dove Standard Reference Materials SRM 768 Temperature reference standard for use below 0.5 K. National Bureau of Standards, US Department of Commerce, Special Publication 260-62 (1979)... 

The International Reference Standard for neomycin is defined as containing 680 units of activity per mg or alternatively 1 unit of activity is contained in 0.00147mg of standard material. 

The Cl shift of Mossbauer spectra provides a measure of the total electron density in the nucleus of an atom, i/r(o), relative to some reference standard. For Fe, 8 is quite sensitive to valence, coordination number, or number and type of bonds to its ligands. Unlike chemical shifts in NMR spectra which are frequently dominated by the spin... 

The preferred method of analysis for imparity qnantification is through the comparison to an external standard. External standard methods rely on a stable chromatographic system and the ability to obtain a reference standard for the imparity nnder test. 

Most currently used oxidant and ozone monitors need to be calibrated with a predetermined concentration of ozone in air. Regardless of the principle used to measure ambient ozone or oxidant concentrations, the primary reference standard for calibrating each monitoring device or system should be identical everywhere. This requirement remains to be achieved in practice. Up to June 1975, at least seven calibration procedures were practiced in the United States. These are listed in Table 6-5... 

TABLE 6-5 Primary Reference Standards for Calibration of Ozone or Oxidant Analysis... 

This model of course makes a lot of assumptions and there are quite a few problems. It is not possible to have appropriate reference standards for all possible chemical measurements, very often there are no common links (i.e. reference to a common basis, which is ideally the SI), laboratories do not always use the standards in an appropriate way and very often the uncertainty concept is not used at all ... 

Mercury dimethyl is used in inorganic synthesis and as a reference standard for Hg-NMR. 

Potassium hydrogen phthalate has many uses in analytical chemistry. It is a primary standard for standardization of bases in aqueous solutions. Its equivalent weight is 204.2. It also is a primary standard for acids in anhydrous acetic acid. Other applications are as a buffer in pH determinations and as a reference standard for chemical oxygen demand (COD). The theoretical COD of a Img/L potassium hydrogen phthalate is 1.176mg O2. 

The Food and Nutrition Board of the Institute of Medicine (lOM) has been developing reference standards for vitamins and other nutrients called Dietary... 

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