Chemical reagents tests

Resistance of Adhesive Bonds to Chemical Reagents, Test for D 896... 

Test Method for Resistance of Adhesive Bonds to Chemical Reagents Test Method for Applied Weight per Unit Area of Liquid Adhesive Test Method for Applied Weight per Unit Area of Liquid Adhesive Test Method for Peel or Stripping Strength of Adhesive Bonds Practice for Exposure of Adhesive Specimens to Artificial (Carbon Arc Type) and Natural Light... 

Extracts of pure proanthocyanidins have been prepared using reversephase and adsorption chromatography, and their identity confirmed with 13C nuclear magnetic resonance imaging, ultraviolet spectroscopy, and chemical reagent tests (Howell and Vorsa, 1998). 

Resistance of Adhesive Bonds to Chemical Reagents, Test for (D 896) Cleavage Strength of Metal-to-Metal Adhesive Bonds, Test for (D 1062)... 

Chemical Reagents. Wherever chemical reagents are specified in the following tests, analytical reagent grade shall be used... 

Insufficient testing is one of the major causes of method failure. The amount of data needed to publish a new procedure in a peer-reviewed journal and the procedural detail supplied therein are often insufficient to allow a different user to validate a method rapidly. The developer should evaluate if the method will work using chemicals, reagents, solid-phase extraction columns, analytical columns, and equipment from various vendors. Separate lots of specific supplies within a vendor should be evaluated to determine if lot-to-lot variation significantly impacts method performance. Sufficient numbers of samples should be assayed to estimate the lifetime of the analytical column and to determine the effects of long-term use on the equipment. 

The analytic principles that have been applied to accumulate air quality data are colorimetry, amperometry, chemiluminescence, and ultraviolet absorption. Calorimetric and amperometric continuous analyzers that use wet chemical techniques (reagent solutions) have been in use as ambient-air monitors for many years. Chemiluminescent analyzers, which measure the amount of chemiluminescence produced when ozone reacts with a gas or solid, were developed to provide a specific and sensitive analysis for ozone and have also been field-tested. Ultraviolet-absorption analyzers are based on a physical detection principle, the absorption of ultraviolet radiation by a substance. They do not use chemical reagents, gases, or solids in their operation and have only recently been field-tested. Ultraviolet-absorption analyzers are ideal as transfer standards, but, as discussed earlier, they have limitations as air monitors, because aerosols, mercury vapor, and some hydrocarbons could, interfere with the accuracy of ozone measurements made in polluted air. 

References on Impurities in Chemicals Kraueh, The Testing of Chemical Reagents for Purity, p. 256 (1902) Murray, Standards and Tests for Reagents and C. P. Chemicals, p. 408 (1927) Schade, J. Am. 

ASTM D543, Test Methodfor Resistance of Plastics to Chemical Reagents, Vol. 8.01, ASTM, Philadelphia, Pa., 1989. 

The test should always be carried out on the single fibres and without previously subjecting them to any preliminary treatment with water or other chemical reagents. 

Notes aThe numbering refers to the position of the homologous residue in the SR Ca -ATPase (Figure 15). bThe labeled enzymes have lost transport function with ATP as substrate, but since the label occupies the ATP site, this does not mean that the residue is essential. The functional role of the residue itself has been tested by mutagenesis (Figure 16) and by modification with other chemical reagents (Stefanova et al., 1993). The (i) for inactive indicates that transport function was lost in all studies, in which the residue was altered. 

Documented testing procedures make the work in the laboratory controlled chemicals, reagents, samples, subsamples, analyses, and analysis results are traceable (chain-of-custody)... 

ASTM D 896-84, Standard Test Method for Resistance of Adhesive Bonds to Chemical Reagents, specifies the testing of adhesive joints for resistance to solvents and... 

Note Certain chemical reagents specified in FCC test procedures may be considered to be hazardous or toxic by the Occupational Safety and Health Administration, by the Environmental Protection Agency (under provisions of the Toxic Substances Control Act), or by health authorities in other countries in which the Food Chemicals Codex is recognized. In preparing this edition, the... 

Dry reagent chemistries have been described for the analysis of a variety of blood constituents. These include metabolites, enzymes, electrolytes, hormones, and therapeutic drugs. A partial list is presented in Table 3. With the exception of electrolytes, nearly all analyses depend on enzyme-mediated chemistries and that includes immunochemical assays. A brief survey of element structures will illustrate how physical functions and chemical reactions used in conventional multistep procedures are integrated in the construction of dry reagent test devices. These examples will illustrate how reactions in dry reagent elements can be compartmentalized and how end produas are shunted to other compartments for further reaction. In its final form, each element provides a complete analytical procedure. 

The concept of traces in chemistry probably originates from descriptions of the purity of chemical reagents, which in the nineteenth century included a statement such as trace for minor components when a more accurate description was not needed or not possible. One early example of determination of traces was the Marsh test, developed as early as 1836 for the determination of very small amounts of arsenic, which was of primary importance in toxicology. 

Figure 11 Plots comparing results of water and SLF leach tests performed on settled dusts generated by the WTC collapse. One part dust is added to 20 parts water or SLF at 37 °C and mixed for 24 h, with the leachate filtered (<0.45 p,m) and analyzed. The composition of the SLF used in the extraction is a variation on the recipe provided by Bauer et al (1997) pH 7.4 Na—150.7 mM Ca—0.197 mM NH4—lOmM Cl— 126.4 mM SO4—0.5 mM HCO3—27 mM HPO4— 1.2 mM Glycine—5.99 mM Citrate—0.2 mM. Other metals shown in the SLF blank were contributed as trace constituents of the various chemical reagents used to make up the fluids.

Effect of Chemical Addition In order to insure that surfactants are compatible with the commercial slurries containing chemical reagents, two slurry chemistries (ferric nitrate and hydrogen peroxide) were employed to test the efficiency of the selected surfactants in the presence of chemicals. The results showed that the effect of surfactant on stability and removal rate is not influenced by the presence of the chemicals. Both hydrogen peroxide and ferric nitrate based chemistries were added to Brij 35 based alumina slurries. 

Molybdenum does not dissolve in most common chemical reagents. A chemical reagent is a substance that takes part in a chemical reaction, such as an acid or an alkali. For example, molybdenum does not dissolve in hydrochloric acid, hydrofluoric acid, ammonia, sodium hydroxide, or dilute sulfuric acid. These chemicals are reagents often used to test how reactive a substance is. Molybdenum does dissolve in hot strong sulfuric or nitric acids, however. The metal does not react with oxygen at room temperatures, but does react with oxygen at high temperatures. 

ASTM D 543-87 Standard Test Method for Resistance of Plastics to Chemical Reagents, 1 pp (DOD Adopted) (FSC 9330) (MR) (Comm D-20)... 

Foam Separation by Dispersed Air Flotation Cell Chemical Reagents for Adsorptive Bubble Separation Laboratory Foam Separation Tests Engineering Applications... 

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