International standardization index

Furthermore, each sub-category given in Table 6.2 can be divided according to product viscosities, which are classified in the international standard ISO 3448 (French standard NF ISO 3448, index T 60-141). 

The color of TSR L is measured with a Lovibond Comparator using methods outlined in the relevant International Standard (16). Raw mbber is molded into a disk 1.6 mm thick, and the color is compared and matched with that of standard glass disks. These glass disks provide a color index scale in which the higher index values correspond to darker colors. Generally the specification for TSR L is a maximum Lovibond individual value of 6 and range... 

In Raman spectroscopy the intensity of scattered radiation depends not only on the polarizability and concentration of the analyte molecules, but also on the optical properties of the sample and the adjustment of the instrument. Absolute Raman intensities are not, therefore, inherently a very accurate measure of concentration. These intensities are, of course, useful for quantification under well-defined experimental conditions and for well characterized samples otherwise relative intensities should be used instead. Raman bands of the major component, the solvent, or another component of known concentration can be used as internal standards. For isotropic phases, intensity ratios of Raman bands of the analyte and the reference compound depend linearly on the concentration ratio over a wide concentration range and are, therefore, very well-suited for quantification. Changes of temperature and the refractive index of the sample can, however, influence Raman intensities, and the band positions can be shifted by different solvation at higher concentrations or... 

The international normalized ratio (INR) is a method to standardize repotting of the prothrombin time, using the formula, INR = (PTpatie t/PTcontroi)ISI, where PT indicates the prothrombin times (for the patient and the laboratory control), and ISI indicates the international sensitivity index, a value that varies, depending upon the thromboplastin reagent and laboratory instrument used to initiate and detect clot formation, respectively. 

Sample preparation, injection, calibration, and data collection, must be automated for process analysis. Methods used for flow injection analysis (FLA) are also useful for reliable sampling for process LC systems.1 Dynamic dilution is a technique that is used extensively in FIA.13 In this technique, sample from a loop or slot of a valve is diluted as it is transferred to a HPLC injection valve for analysis. As the diluted sample plug passes through the HPLC valve it is switched and the sample is injected onto the HPLC column for separation. The sample transfer time typically is determined with a refractive index detector and valve switching, which can be controlled by an integrator or computer. The transfer time is very reproducible. Calibration is typically done by external standardization using normalization by response factor. Internal standardization has also been used. To detect upsets or for process optimization, absolute numbers are not always needed. An alternative to... 

International standard reference material (Oxalic acid SRM 4990C) is supplied worldwide by the National Institute of Standards and Technology (http //www.nist.gov) other reference materials of different certified 14C concentrations are provided by the International Agency of Atomic Energy (http //www naweb.iaea.org/nahu/nmrm/nmrm2003/index.htm). 

GPC analyses were performed with a Waters Model 244 chromatograph using Microstyragel columns. Both differential refractive index and UV (254 nm) detectors were used. THF was the eluant with a flow rate of 2 ml min-1. A benzene internal standard was employed to correct for flow variations and for normalization of the integrated peak areas. The column set was calibrated using nearly monodispersed polystyrene standards and all molecular data are reported as polystyrene-equivalent molecular weights. 

A comparative study of the analysis of aliphatic amines by GC-FID, GC-TSD and HPLC with refractive index detector (RID), using isopropylamine as internal standard, gave good results in all cases. Determination of trimethylamine oxide by HPLC with a pulsed amperometric detector was problematic136. 

European situation. An overview of the complete situation in the EU-countries is still lacking (Andersson 1998). A comprehensive approach suggested to assess animal welfare is the elaboration of an animal welfare index, which would be made up of several different components (Bartussek 1988 Sundrum et al. 1994). Such an index could be defined in national and international standards and accelerate the development of standards and control measures for a common definition for organic animal husbandry. 

A widespread method for determining the induction period for autoxidation of oils and fats consists of passing a continuous stream of air through the heated sample and collecting the volatile acids evolved in a water trap, where they are determined on a real time basis. The time plot usually presents a flat appearance for a certain period and then takes off in an accelerated manner. This test is the basis of several national and international standards (e.g. AOCS Cd 12b-92—oil stability index" ISO 6886—accelerated oxidation test for oxidative stability of fats and oils ) and the design of the Rancimat equipment, where the end determination is based on conductivity measurements . In addition to oxidation stability as determined by the Rancimat method and POV, which negatively affects virgin olive oil stability, other nonstandard properties were proposed for better assessment of the quality of this oil, namely LC determination of Vitamin E (21), colorimetric determination of total polar phenols and UVD of total chlorophyll. ... 

Internal standards of rather close relationship to the compounds analysed should be used, e.g. homologues (M-i-14) or isotopomers of analytes ( H or labelling), owing to optimal identity of physical or chemical properties (e.g. Ko-vats index in GC). 

Therefore, a gas chromatographic internal standard method was employed to quantify these two index compounds in the storage study. 

X-Ray Diffraction Analysis. X-ray powder diffraction data for indexing were obtained with a General Electric XRD-6 diffractometer. Samples were sealed in glass capillaries (0.5 mm o.d.) and exposed to nickel-filtered CuKa radiation. KCl or iridium was used as an internal standard. X-ray powder diffraction intensity data were obtained with a General Electric XRD-5 unit. Here,... 

The VOCs in the inside air are enriched by means of active sampling on Tenax TA tubes, which are thermodesorbed. After internal standards have been added, analysis is carried out by capillary GC—MS. The hundred compounds on the chromatogram which have the most intense signals are identified by retention index and mass spectrum (Wensing, Schulze and Salthammer, 2002), and are then semi-quantitatively evaluated with toluene as the reference substance. The toluene equivalents are summed, and this result serves as a semi-quantitative estimation of the total VOC concentration (TVOC). 

Toraya s WPPD approach is quite similar to the Rietveld method it requires knowledge of the chemical composition of the individual phases (mass absorption coefficients of phases of the sample), and their unit cell parameters from indexing. The benefit of this method is that it does not require the structural model required by the Rietveld method. Furthermore, if the quality of the crystallographic structure is poor and contains disordered pharmaceutical or poorly refined solvent molecules, quantification by the WPPD approach will be unbiased by an inadequate structural model, in contrast to the Rietveld method. If an appropriate internal standard of known quantity is introduced to the sample, the method can be applied to determine the amorphous phase composition as well as the crystalline components.9 The Rietveld method uses structural-based parameters such as atomic coordinates and atomic site occupancies are required for the calculation of the structure factor, in addition to the parameters refined by the WPPD method of Toraya. The additional complexity of the Rietveld method affords a greater amount of information to be extracted from the data set, due to the increased number of refinable parameters. Furthermore, the method is commonly referred to as a standardless method, since the structural model serves the role of a standard crystalline phase. It is generally best to minimize the effect of preferred orientation through sample preparation. In certain instances models of its influence on the powder pattern can be used to improve the refinement.12... 

X-ray powder diffraction investigations were made in cooperation with P. Norby (Oslo University) and I.G. and E. Krogh Andersen (Odense University). For phase identification and lattice costants determination a Guinier-Hagg camera has been used (CuKa =1.5451 (10) quartz internal standard a=4.91309 A, c=5.40426 A (11). The diagrams were indexed and lattice constants refined by least square... 

Standard methods for measuring the refractive index of oils and fats are published by IUPAC (standard method 2.102, Paquot Hautfenne, 1987), the American Oil Chemists Society (AOCS Official Method Cc 7-25, Firestone, 1998) and the International Standards Organization (International Standard 1739-1975 (E), ISO, 1975). The last specifically applies to the measurement of the refractive index of the fat from butter, and was developed jointly with the International Dairy Federation and the American Oil Chemists Society. 

ISO 1975. ISO 1739 1975 Butter—Determination of the Refractive Index of the Fat (Reference Method), International Standards Organization, Geneva. 

The present 1993 edition is a futher revision of the 1988 edition, incorporating the recent resolutions of the CGPM, the new international standards ISO-31, and new recommendations from IUPAP and from other IUPAC Commissions. Major additions have been made to the sections on Quantum Mechanics and Quantum Chemistry, Electromagnetic Radiation, and Chemical Kinetics, in order to include physical quantities used in the rapidly developing fields of quantum chemical computations, laser physics, and molecular beam scattering. New sections have been added on Dimensionless Quantities, and on Abbreviations and Acrohyms used in chemistry, and a full subject index has been added to the previous symbol index. 

In this system, amphetamine, 3,4-methylenedioxyamphetamine (MDA) and the A-methyl and A-ethyl analogues of the drugs were derivatized, with 4-chloroamphetamine being used as the internal standard. For powders, solutions were prepared at concentrations of 1 mgml in methanol and a 100 til aliquot blown dry under nitrogen. To the residue was added 50 p.1 of 0.5 M KOH and 500 p,l of toluene. The mixture was then shaken for 30 s and centrifuged, after which the toluene layer was recovered and HFBA (5 til) added. The excess reagent was neutralized with 500 p,l of 10% NaHCOs and an aliquot (1 ttl) analysed by GC-MS. Each of the amphetamines and the A-alkylated derivatives could be separated and identified on the basis of retention index and mass spectral data. 

Retention index The ratio of the retention times of the test sample and an internal standard. 

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