Standardization specific reagents

Table 11.30 lists standard solutions for precipitation titrations and Table 11.31 lists specific reagents as indicators, adsorption indicators, and protective colloids for precipitation titrations. 

If there is any doubt as to the purity of the reagents used, they should be tested by standard methods for the impurities that might cause errors in the determinations. It may be mentioned that not all chemicals employed in quantitative analysis are available in the form of analytical reagents the purest commercially available products should, if necessary, be purified by known methods see below. The exact mode of drying, if required, will vary with the reagent details are given for specific reagents in the text. 

The O-ECAT reagent is a superior alternative to the use of 2,4-dinitrophenylhydrazine (DNPH Chapter 1, Section 1.1) in the study of protein oxidation. DNPH modification produces detectable complexes, but it does not provide information as to what amino acids are involved. O-ECAT modifies carbonyl end products of protein oxidation and in addition, it can provide exact information as to the amino acids that were oxidized. Mass spec analysis of modified proteins performed after proteolysis gives the exact amino acid sequences including the sites of O-ECAT reagent modification. The same antibody that is specific for the metal chelate portion of the standard ECAT reagent also can be used to capture and detect the O-ECAT... 

FIA has also found wide application in pharmaceutical analysis.214,215 Direct UV detection of active ingredients is the most popular pharmaceutical analysis application of FIA. For single component analysis of samples with little matrix interference such as dissolution and content uniformity of conventional dosage forms, many pharmaceutical chemists simply replace a column with suitable tubing between the injector and the detector to run FIA on standard HPLC instrumentation. When direct UV detection offers inadequate selectivity, simple online reaction schemes with more specific reagents including chemical, photochemical, and enzymatic reactions of derivatization are applied for flow injection determination of pharmaceuticals.216... 

Fig. 6. Immune complexes in sera from patients with disseminated gonococcal (GC) infection. Immune complexes were run in the staphylococci binding assay. Isotype-specific reagents and an anti-GC reagent were used to detect immune complex material. Standard deviations were determined on a panel of 27 normal sera.

Identify the materials used and give information on the degree of and criteria for purity, but do not reference standard laboratory reagents. Give the chemical names of all compounds and the chemical formulas of compounds that are new or uncommon. Use meaningful nomenclature that is, use standard systematic nomenclature where specificity and complexity require, or use trivial nomenclature where it will adequately and unambiguously define a well-established compound. 

Where peptide chemistry can make a contribution toward the proof of protein structure is in the application and continued formulation of degrada-tive techniques. Since fragmentation of the protein molecule to smaller peptides is probably the key reaction in degradative processes, the search for specific reagents for the selective cleavage of various peptide bonds and the standardization of existing techniques is of prime importance (Katsoyannis, 1961). 

ASTM standard specification for reagent water, designation D 1193-77 (reapproved 1983). American Society for Testing Materials, Philadelphia. 

For routine assays requiring analysis of large numbers of samples, micro-titre or multi-well plate readers have been developed. These consist of single-beam instruments in which the samples are contained in standard 96-well (8x12) plates, each well containing a separate sample. This allows large numbers of samples to be measured rapidly, often automatically under robotic control. The multi-well/micro-titre plates themselves are often coated with specific reagents so that particular analyses may be done rapidly and routinely in situ. 

The following starting reagents were used for the synthesis of nanosized pigments with the anticorrosive properties on a basis of the zinc phosphates, namely zinc acetate Zn(CHfdOO) -2Hf) (State standard specification 4174-77) from the Sfera Sim with the content of the main substance 99.5% and ammonium phosphate (NHJPO (State standard specification 4174-78) from the Sfera Sim with the content of the main substance " 99.0%. 

The distillation method of moisture determination requires the collection and determination of the water evolved from the coal when the sample is heated in a boiling solvent which is itself immiscible with water. The solution and extraction methods require either solvent extraction of the water from the coal (followed by subsequent determination of the water content of the solvent) or use of a standard reagent which will exhibit differences in concentration by virtue of the water in the coal. The chemical methods of water determination invoke the concepts of direct chemical titration of the water or chemical reaction between the water and specific reagents which causes the evolution of gases and the water is determined by measurement of the volume produced. Finally, the electrical method requires the measurement of the dielectric constant of the coal from which the water content can be determined. 

Numerous quoted standard specifications refer to distillation ranges as criteria of purity or suitability for use, or as indicators of performance. Published standards for analytical reagents in the AnalaR range and similar documentation by the American Chemical Society refer to distillation ranges as criteria of purity for appropriate materials. 

Determine that appropriate reference standards, solvents, reagents and other solutions were used, and that they met quality control specifications (e.g. had been stored appropriately, were notout of date etc.). 

Some of these same techniques as well as other standard methods can be used to determine the purity of the protein polymer preparations. PAGE, high performance liquid chromatography (FIPLC), and moisture analysis are used to analyze the entire sample in bulk. The amount of non-product species which are detected can be used to estimate a maximum purity. Specific contaminants such as polysaccharides, triglycerides, nucleic acids, and endotoxin are detected by specific tests. Assays for host cell derived DNA and antigens is performed with specific reagents developed for these agents. 

Standard Test Method for Copper Strip Corrosion by Industrial Aromatic Hydrocarbons Standard Test Methods for Nonrigid Vinyl Chloride Polymer Tubing Used for Electrical Insulation Standard Practice for Substitute Ocean Water Standard Specification for Reagent Water... 

ASTM Standard. D1193-91 Standard Specification for Reagent Water, 1997. 

Dissolve 10.21 g of analytical reagent quality (primary buffer-standard specification) potassium hydrogen phthalate, KHCgH404, in distilled water and make the volume to 1000 ml in a measuring flask. Store in a glass bottle. The solution is stable almost indefinitely in the absence of evaporation. The formation of a slight turbidity introduces no error. 

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