Nitric acid reagent, hydroxylamine

The action of hydroxylamine and sodium acetate in ethanol upon picryl chloride was stated to give 4,6-dinitrobenzofuroxan, and probably some of this compound was formed, although it was later shownthat much of the original work was faulty. A report that hydroxylamine and 2,4,5-trinitrotoluene give 5-methyl-6-nitro-benzofuroxan has been found to be incorrect. Benzofuroxan has not been prepared by V-oxidation of benzofurazan, and it seems unlikely that this could be achieved, since benzofuroxan itself is oxidizable by powerful reagents to o-dinitrobenzene (Section VI, B). A report of the oxidation by nitric acid of anthraceno[l,2-c]furazan to the furoxan is incorrectlv abstracted. 

Reagents. Sulphuric acid (18 N), nitric acid (sp. gr. 1.42), potassium permanganate 5% (m/v) solution, potassium persulphate 5% (m/v) solution, sodium chloride 12% (m/v)—hydroxylamine sulphate 12% (m/v) solution. 

Sample Treatments. Blood (1 ml) and fecal samples (1 g dry-matter) were ashed on hot plates by sequential treatment with concentrated nitric acid and 30% hydrogen peroxide. The white residue of each sample was dissolved in 3-5 ml of 6 N HCl, and the final volume was brought up to 25 ml with 6 N HCl. Several 0.1 ml aliquots were transferred to test tubes, and iron concentrations were determined by a colorimetric method using the Batho-reagent (17) which contains hydroxylamine hydrochloride (10%), sodium acetate (1.5 M), and bathophenan-throline disulfonate (0.5 mM). The analytical precision of iron quantification was evaluated by measuring the iron concentrations of 13 replicates of one imenriched fecal sample. The mean of these measurements was 365.7 ug per gram of dry feces, with a relative standard deviation of 2. 8%. 

The mercury reagent blank for the nitric acid cannot be measured by generating elemental mercury from a solution of 1 3 nitric acid with divalent tin. However, it can be determined by adding potassium permanganate and sulfuric acid, heating the solution to remove the nitric acid, and measuring the mercury after treatment with hydroxylamine sulfate. 

Hydroxylamine hydrochloride, dissolved in acetic or nitric acid, was shown to selectively extract Mn oxyhydroxides and Mn oxides, as well as amorphous Fe oxides (Chester and Hughes, 1967 Chao, 1972 Chao and Zhou, 1983). This reagent was used for the extraction of trace metals associated with hydrous oxides of Fe and Mn in soils (Gupta and Chen, 1975 Stover et al, 1976 Tessier et al, 1979 Harrison et al, 1981 Miller and McFee, 1983 Miller et al, 1986a, b Rule and Alden, 1992 Krishnamurti et al, 1995a Krishnamurti and Naidu,... 

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