Unavailable organic compounds

In the presence of hydrogenation catalysts, certain organic compounds can serve as the hydrogen source. The procedure is useful when hydrogen is unavailable or zoned against only simple equipment is required 18). The... 

Biologically available organic contaminants may find their way into the food chain and be toxic, but they are also more easily decomposed and are thus removed from the environment. Slowly decomposed biologically available organic compounds, such as pesticides, may have long lifetimes in soil and thus pose a hazard to animals and humans. Biologically unavailable compounds, such as tars, produce undesirable characteristics in soil, such as water... 

The extraction tests were exploratory and arbitrary in nature for two reasons relatively little plant material was supplied, with the result that no optimization studies could be carried out and pure material was unavailable for solubility testing. Not only were optimization studies impossible but also the extraction conditions were selected from experience with other complex organic compounds. 

Selenate is the most mobile form of Se. Selenium becomes biologically unavailable by reduction to elemental Se or by formation of metal selenides or Se-sulfides. Inorganic Se compounds can be converted to volatile organic Se such as dimethyl selenide or dimethyl diselenide by... 

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