Environmental transformation product

Environmental Transformation Products of Cyanide Compounds by Medium... 

The various cyanide compounds included in this profile undergo a number of different transformation and degradation reactions in the environment as discussed in the following sections. The resulting environmental transformation products within different media are shown in Table 5-2. 

Precautions should be taken to avoid disulfoton loss from stored water, soil, sediment, crop, and vegetable samples (Belisle and Swineford 1988 Miller etal. 1981 Munch and Frebis 1992 Szeto and Brown 1982). Disulfoton, disulfoton sulfone, and disulfoton sulfoxide were not recovered from spiked well water stored 14 days however, sample extracts were stable for 14 days (84-92% recovery) (Munch and Frebis 1992). In most environmental samples, disulfoton will be present along with its environmental transformation products, disulfoton sulfone, disulfoton sulfoxide, disulfoton oxon, disulfoton oxon sulfone, and disulfoton oxon sulfoxide (Szeto and Brown 1982). Disulfoton and its oxon are very unstable, and they oxidize rapidly to the corresponding sulfoxides. The sulfoxides are relatively stable, but they oxidize slowly to their sulfones, which are most stable (Szeto and Brown 1982). Several methods for determining the metabolites of disulfoton in environmental samples are included in Table 6-2. 

The most studied kinds of explosives are nitroaromatic explosives and their metabolites. Therefore, the emphasis of this review is on properties of nitroaromatic explosives, rather than propellants, pyrotechnics, or munitions, and their interactions with soils. Nitroaromatic explosives are toxic, and their environmental transformation products, including arylamines, arylhydroxyl-amines, and condensed products such azoxy- and azo-compounds, are equally or more toxic than the parent nitroaromatic [3]. Aromatic amines and hydroxylamines are implicated as carcinogenic intermediates as a result of nitrenium ions formed by enzymatic oxidation [4], Aromatic nitro compounds... 

Environmental Transformation Products of Benzene in Various Media... 

Army. 1990b. Environmental transformation products of nitroaromatics and nitramines Literature review and recommendations for analytical method development. Special report 90-2. Aberdeen Proving Ground, MD U.S. Army Toxic and Hazardous Materials Agency, (authored by Walsh ME). 

Walsh ME, Environmental Transformation Products of Nitroaromatics and Nitramines, U.S. Army Corps of Engineers Cold Regions Research Engineering Laboratory, Special Report 90-2, Hanover, NH, 1990. 

Abstract This chapter gives an overview of strategies used in the identification and analysis of environmental transformation products of three important groups of synthetic chemicals pesticides, pharmaceuticals, and personal care products. The characteristics and features of modern mass spectrometric instrumentation coupled to liquid chromatographic separation techniques as well as complementary techniques are presented and examples of their application to the characterization of transformation products of synthetic chemicals are described. Analytical methodologies for the quantitative analysis of the intact parent compounds and their transformation products in the environment are compiled. 

Mixtures of Pesticides and Their Environmental Transformation Products. 217... 

Abstract Persistent environmental transformation products are increasingly being detected in surface waters and previous parts of this volume have discussed methods for prediction and quantification. However, there is not sufficient experimental data on their ecotoxicological potential to assess the risk associated with transformation products, even if their occurrence and abundance is known. Herein, we review computational... 

Keywords Baseline toxicity Ecotoxicology Environmental transformation products Metabolites Mode of toxic action Pharmaceuticals Pesticides Herbicides QSAR... 

All of the above research deals with environmental transformation products of pesticides. However, there are also other groups of chemicals such as pharmaceuticals and hormones, biocides, consumer products, and industrial chemicals, which may also produce persistent transformation products. These products may be produced in the environment by abiotic or biotic processes or produced in humans or animals as a result of metabolism [5]. 

The second case refers to hormones, pharmaceuticals, and other compounds that are ingested, metabolized, and excreted by mammals (Table 1). Usually a hormone or pharmaceutical is extensively metabohzed in the body and is excreted by mammals as a mixture of different metabolites. Although the general belief is that metabolism renders a drug more water soluble and consequently less hazardous for the aquatic environment, there are exceptions for pro-drugs and specifically acting metabolites. The third case refers to environmental transformation products of pesticides and other environmental pollutants (Table 1), which are formed both by abiotic and biotic transformation processes. 

Table 3 Toxicity of diuron and its environmental transformation products in the bioluminescence inhibition test with Vibrio fischeri. Baseline toxicity estimates stem from physicochemical data presented in Fig. 4, baseline QSAR are given in [42], and experimental toxicity data in [4] moa = mode of action...

Human and veterinary pharmaceuticals are often highly metabohzed before they are excreted into wastewater or the environment. Thus, we have to consider both the metabohsm during the pharmacokinetic phase in the target organism and the environmental transformation processes. For simphcity, we focus in the following on the metabohtes formed in organisms, but environmental transformation products could be treated in an analogous way as the pesticides discussed above. Also veterinary and human pharmaceuticals can be approached in a similar fashion but the examples below refer to human pharmaceuticals. 

Demand for environmentally compatible and toxicologically acceptable explosives and propellants. Examples are replacements for TNT, RDX and HMX since nitro-explosives per se, as well as their environmental transformation products, are toxic. 

This exemption cannot be invoked if the substance, any reasonably anticipated metabolites, environmental transformation products, or byproducts of the substance, or any reasonably anticipated impurities in the substance may cause, under anticipated conditions of manufacture, processing, distribution... 

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