INDEX degradation products

The list of synonyms included in the Alphabetical index is by no means exhaustive. Although it contains a large number of formal chemical and biological names, it primarily contains historical names, military code names, and common names for the agents, precursors, components, and degradation products included in this handbook. In some instances, names that have been popularized in the media but have no other historical connection to the agent have been included. 

An index is included at the end of the book which lists potential sources or origins for the contaminant of concern of interest. The index also includes compounds for which degradation products are known, e.g., the presence of 1,1-dichloroethane at a site may be indicative of a release containing 1,1,1-trichloroethane (where 1,1-dichloroethane is present as an impnrity) or it may be a degradation product of 1,1,1-trichloroethane. Therefore, under the 1,1-dichloroethane entry, the reader is directed to the chemical profile 1,1,1-trichloroethane. Moreover, the index inclndes compounds which occur as additives to various products, e.g., acrolein nsually contains hydroqninone to prevent polymerization. Many commercial prodncts released into the enviromnent may contain other compounds present as impurities, e.g., 1,4-dioxane may contain the impurities acetic acid, 2-methyl-1,3-dioxolane, and bis(2-chloroethyl) ether. 

Degradation Product, Impurities, and Chemical Composition Index... 

A method similar to K value is the Kj value index that is used for freshness evaluation of fish that accumulate more inosine than hypoxanthine during spoilage (24). The K value is illustrated in Figure 3 (18,19,20,24). K is used with salmon, halibut, yellowtail, and numerous other tropical fish, while K value is reliable for catfish, white flounder, ocean perch, English sole, and various other species (24). The Kj value can be utilized for species specified for K value but not vice versa due to sensitivity of Kj value to the build up of hypoxanthine and not the total sum of degradation products as needed with K value (24). 

Depolymerization, elimination, and statistical chain-scission reactions can be used for polymer analysis. When the monomer is the main degradation product obtained, it can easily be identified by boiling point and refractive index. 

To a plastic producer (i.e. processor), melt index is one property that is needed in order to evaluate whether the same process can be used irrespective of whether it uses virgin or recycled polymers. This will tell if it is possible to process the recycled polymeric materials in the same set-up as usual. Several other properties are needed in order to quality mark the materials. The melt index is related to what final tensile properties a product obtains, this in turn has an impact on the expected life-time. The purity of a recyclate stream with respect to the amount of foreign polymer in the stream has an impact on melt-index, but will also be an important factor for the final mechanical properties. Another very important property is the amount of low molecular weight compounds, which may be of vastly different types. Typically such an analysis will show the presences of additives and their degradation products, degradation products of the polymeric matrices, traces of solvents, initiators, or catalysts, compounds related to the use of the plastics and others. 

Active Oxygen Method for Fat Stability (AOM) (Cd 12-57) determines the time (in hours) for a sample of fat or oil to attain a predetermined peroxide value (PV) under the conditions of the test. The method is used to estimate the comparative oxidative stability of fats and oils. The method has been placed in surplus, in favor of Cd 12b-92 (Oil Stability Index), but retains official status and is still used in domestic industry. p-Anisidine Value (AV) (Cd 18-90) determines the amount of aldehydes (principally 2-alkenals and 2,4-dienals) in animal and vegetable fats and oils. These are degradation products of peroxides, which are not removed by bleaching. Some fats and oils chemists propose increased use of this method in purchase specifications. Bleaching Test for Soybean Oil (Cc 8e-s63) determines the color of a sample of soybean oil after treatment with a specified bleaching earth. Specific methods exist for other oil species. 

While compendial standards are available for some monographed article impurities, it may be difficult at times to obtain pure standards of impurities. Manufacturers of pharmaceuticals function as a potential source for obtaining reference standards of impurities, which may be synthesis precursors, process intermediates, or degradation products. The characterization and evaluation of these impurities reference standards should be constant with their intended use. In many cases, analytical procedures are developed and validated, where the response of an impurity is compared to that of the new drug substance itself. Response factor evaluation of impurities at the chosen detection wavelength is necessary to determine if a correction factor is needed (when the responses differ). Potentiometric detection, fluorescence/ chemiluminescence detection, and refractive index detection are some examples of detection modes available for compounds that may not be suitable for UV detection. 

Alkaloid Amino acids in peptide moiety Degradation products Peak detectable by GLC ) (min) Ret. index MH+ (CI-MS)... 

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