Nitrite isotope ratios

In summary, a considerable body of enzymatic, genetic, and analytical data supports the view that the major, if not sole, pathway of denitrification involves NO as an obligatory intermediate and requires the action of nitric oxide reductase. On the other hand, the ability of nitrite to modify nitrosyl transfer ratios and the N isotope fractionation factor during its reduction, are consistent with the reductive scheme of Averill and Tiedje (1982). It was suggested (Goretski... 

Poth and Focht (1985) reported on a series of experiments with N. europaea in which [ NJnitrite or [ N]nitrate was mixed with NH, and the rates of formation and isotope compositions of nitrite and N2O were followed. The systems were either well oxygenated (shaken) or poorly oxygenated (static). When shaken, no N2O was produced by the cultures. With static cultures, N2O but not N2 was produced in the presence of nitrite but not nitrate, and nitrite was the preferred source of N for N2O. The observed N20/ N20 ratio was 0.25 rather... 

Iindau and Spalding [21] have studied the effects of 2 M potassium chloride extractant ratios of between 1 1 to 1 10 on nitrate recovery in nitrate and nitrite extractions from soil. Preliminary data indicated that concentrations of extractable nitrate and nitrogen isotopic values were influenced by the volume of extractant. The 1 1 extractions showed decreasing nitrogen isotope values with increasing nitrate levels, whereas in the 1 10 extractions these values were independent of each other. Incomplete extraction occurred for the 1 1 ratios. The ratio required for maximal recovery was not determined. 

Radioactivity and Toxicity. Table III lists the radionuclides in aged waste, their half-lives, the expected radioactivity of each after 10 years aging, and the relative toxicity of each. Relative toxicity is defined as the ratio of the concentration of a given isotope to its maximum permissible concentration in public zone water. Mercury, nitrate, and nitrite (although not radioactive) are also listed because their toxicity is actually greater than that of many of the radioactive nuclides. Sr and Cs are... 

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