Nitrogen ammonium

Y. Ogata and M. Tsuchida [J. Org. Chem. 20, 1631 (1955)] have calculated the energy of electrostatic interaction of the oxygens of the nitro group and the ammonium nitrogen. 

The methane content of the first UASB reactor was ca. 60%. The NH4-N removal efficiency of the total system was 99.6%. Ammonium nitrogen was converted to nitrate in the aerobic system via nitrification. The BOD5/COD value obtained at the final stage was in the range 0.12 to 0.15. 

When a CF2H group is attached to an ammonium nitrogen, its fluorines are considerably shielded relative to the respective amine. Thus, the fluorine chemical shifts of difluoromethyl trialkyl ammonium salts are in the -113- to -115-ppm range, as exemplified by difluoromethyl triethyl ammonium chloride (Scheme 4.27). 

Selmer and Sorenson [52] have described a procedure for extraction of ammonium from seawater for 15N determinations. In this method ammonium nitrogen was converted to indophenol and concentrated onto an octadecylsi-... 

Marsh et al. [47] have described an apparatus based on an autoanalyser system for the automatic preparation of soil extracts for mineral nitrogen determination. It consists of a reagent adder, which adds the correct volume of extractant for an approximately weighed amount of soil, and a sample preparation unit, which mixes, filters, dilutes and loads samples on to an autoanalyser sampler. A labour saving of 60% is achieved in this method compared to manual method. Examples are given of the determination of nitrate plus nitrate nitrogen and ammonium nitrogen. 

Tests were carried out to compare the efficiency of extraction results obtained using a manual weighing and sample preparation method, and the reagent adder and sample preparation unit. Extracts of four replicates of ten soils were prepared by each method and analysed for nitrate- plus nitrite-nitrogen by a diazotisation and coupling reaction with sulphanilic acid and N-(l-naphthyl)ethylenediamine and ammonium-nitrogen by an indophenol method. These methods are described fully by Greaves et al. [48]. 

Table 12.8 Determination of ammonium-nitrogen in soil after extraction by manual and automatic techniques... 

ESI(+), however, mainly produced the [M]+ ions at mlz 599 as well as a smaller number of dealkylated ions [M — CH2]+ at 585 (cf. Fig. 2.12.7), whereas ESI(—) predominantly produced the mlz 583 [M — H—CH3] ion, which was also found under APCI(—) conditions. This compound was the first type of cationic surfactants that could be ionised in the negative mode, even though it contained ammonium nitrogen [37]. 

The nitrolysis of hexamine is a direct route to the military high explosives 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX) and l,3,5,7-tetranitro-13,5,7-tetraazacyclooctane (HMX). " The direct nitrolysis of hexamine with dinitrogen pentoxide in absolute ifitric acid provides RDX in 57 % yield. RDX prepared by this process is exceptionally pure, but other reagents, like ammonium nitrate-nitric acid-acetic anhydride, give much higher yields, partly because they use ammonium nitrate to supplement for ammonium nitrogen deficiency in the reaction. 

Discussion 5.6. Determination of organic pius ammonium nitrogen... 

Heat the flask gently until frothing ceases, more strongly until the solution clears, and then for a further 1 h with the sulphuric acid condensing in the lower part of the neck of the flask. Allow to cool, carefully add approximately 100 ml of water and warm to dissolve the soluble material. When cool, transfer quantitatively into a 250-ml volumetric flask and dilute to 250 ml. Retain the diluted digest for the determination of ammonium nitrogen. 

Fujinari EM, Courthaudon LO. Nitrogen-specific liquid-chromatography detector based on chemiluminescence—Application to the analysis of ammonium nitrogen in waste-water. Journal of Chromatography 592, 209-214, 1992. 

Drolc, A., Ros, M., and Cotman, M. (2004), Establishment of traceability of ammonium nitrogen determination in wastewater, Anal. Bioanal. Chem., 378,1243-1250. 

There are no a-amino fluorides because of the reactivity of this functional combination, and for the same reason, there are few /1-amino fluorides. However, when attached to the less basic nitrogen of a benzimidazole or benzotriazole, the CH2F or CHFR groups are much more stable (Scheme 3.35). Note that when attached to a partially positive nitrogen, as in an imidazolium compound, or a fully positive ammonium nitrogen, the respective fluorines become progressively more shielded. a-Fluoroazides can be prepared but are also not very stable. 

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