Micro-Kjeldahl Method for Nitrogen in Certain Organic Compounds Containing Nitrogen-Nitrogen and Nitrogen-Oxygen Linkages

Steyermark, Al; McGee, Barbara E.; Bass, Esther A.; Kaup, R. R.

doi:10.1021/ac60141a036

Cited by 27 publications

(7 citation statements)

References 9 publications

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“…Imidazole and 2,5dimethyl-1,3,4-thiadiazole yielded only 5% to 25% of their theoretical nitrogen. These results are not surprising, because the N-N linkage in pyrazolones and similar compounds has been reported as extraordinarily resistant to Kjeldahl digestion (24)(25)(26)(27).…”

Section: Methodsmentioning

confidence: 56%

Chemiluminescence vs. Kjeldahl determination of nitrogen in oil shale retort waters and organonitrogen compounds

Jones¹,

Daughton²

1985

Anal. Chem.

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Section: Methodsmentioning

confidence: 56%

Chemiluminescence vs. Kjeldahl determination of nitrogen in oil shale retort waters and organonitrogen compounds

Jones¹,

Daughton²

1985

Anal. Chem.

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“…Organic matter content was determined by Walkley-Black Dichromate reduction method [14]. Total N in the manure was determined using the micro-Kjeldahl method [19].…”

Section: Chicken Manure Analysismentioning

confidence: 99%

Influence of Chicken Manure Amendment on the Thermal Properties of Selected Benchmark Soils in Zambia

Chishala¹,

Phiri²,

Chabala³

2019

OJSS

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Influence of Chicken Manure amendment on the thermal properties of selected Benchmark soils in Zambia was investigated in the laboratory under soil column experiments. Five benchmark soils were exerted to four chicken manure amendment rates of 0% (control), 2%, 4% and 6% on a weight basis. Soil temperature profiles were monitored in soil columns exerted to artificial heat source and generated data was used to compute the thermal properties of the soils. The effect of manure application on the soil thermal properties was strongly related to soil type and application rate. Significant differences (p < 0.05) were observed in volumetric heat capacity, thermal diffusivity and damping depth among the benchmark soils. The volumetric heat capacity varied from 3.87 MJ•m −3 •c −1 (Mushemi series) to 8.62 MJ•m −3 •c −1 (Makeni series) and attributed to differences in soil characteristics. Thermal diffusivity varied from 0.028 m 2 •s −1 (Makeni series) to 0.069 m 2 •s −1 (Mushemi series) a reverse trend to thermal conductivity. A similar trend was observed with damping depth however thermal conductivity was not significantly different among the benchmark soils. The studied soils showed significant differences (p < 0.05) in their thermal properties with chicken manure amendment. Thermal conductivity (λ), thermal diffusivity (D h) and damping depth (d) decreased while volumetric heat capacity (Cv) increased with increased chicken manure addition. The differences in these thermal properties were attributed to differences in soil properties. These results suggest that chicken manure application can be an important intervention in regulation of the thermal properties of the soil and consequently the thermal regime of the soil.

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“…Method 9 (micro-method). The method used differed from that described by Steyermark, McGee, Bass & Kaup (1958) only in that twice the recommended quantities of reagents were employed. This zinc-iron reduction method has proved sucessful with azo and nitro compounds, hydrazines, oximes and other compounds containing N-N and N-O linkages.…”

Section: Determentioning

confidence: 99%

Determination of nitrogen in soil by the Kjeldahl method

1960

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1. The reliability of the Kjeldahl method for the determination of nitrogen in soils has been investigated using a range of soils containing from 0·03 to 2·7% nitrogen.2. The same result was obtained when soil was analysed by a variety of Kjeldahl procedures which included methods known to recover various forms of nitrogen not determined by Kjeldahl procedures commonly employed for soil analysis. From this and other evidence presented it is concluded that very little, if any, of the nitrogen in the soils examined was in the form of highly refractory nitrogen compounds or of compounds containing N—N or N—O linkages.3. Results by the method of determining nitrogen in soils recommended by the Association of Official Agricultural Chemists were 10–37% lower than those obtained by other methods tested. Satisfactory results were obtained by this method when the period of digestion recommended was increased.4. Ammonium-N fixed by clay minerals is determined by the Kjeldahl method.5. Selenium and mercury are considerably more effective than copper for catalysis of Kjeldahl digestion of soil. Conditions leading to loss of nitrogen using selenium are defined, and difficulties encountered using mercury are discussed.6. The most important factor in Kjeldahl analysis is the temperature of digestion with sulphuric acid, which is controlled largely by the amount of potassium (or sodium) sulphate used for digestion.7. The period of digestion required for Kjeldahl analysis of soil depends on the concentration of potassium sulphate in the digest. When the concentration is low (e.g. 0·3 g./ml. sulphuric acid) it is necessary to digest for several hours; when it is high (e.g. 1·0 g./ml. sulphuric acid) short periods of digestion are adequate. Catalysts greatly affect the rate of digestion when the salt concentration is low, but have little effect when the salt concentration is high.8. Nitrogen is lost during Kjeldahl analysis when the temperature of digestion exceeds about 400° C.9. Determinations of the amounts of sulphuric acid consumed by various mineral and organic soils during Kjeldahl digestion showed that there is little risk of loss of nitrogen under the conditions usually employed for Kjeldahl digestion of soil. Acid consumption values for various soil constituents are given, from which the amounts of sulphuric acid likely to be consumed during Kjeldahl digestion of different types of soil can be calculated.10. Semi-micro Kjeldahl methods of determining soil nitrogen gave the same results as macro-Kjeldahl methods.11. The use of the Hoskins apparatus for the determination of ammonium is described.12. It is concluded that the Kjeldahl method is satisfactory for the determination of nitrogen in soils provided a few simple precautions are observed. The merits and defects of different Kjeldahl procedures are discussed.

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Micro-Kjeldahl Method for Nitrogen in Certain Organic Compounds Containing Nitrogen-Nitrogen and Nitrogen-Oxygen Linkages

Abstract: Micro-Kjeldahl procedures are described for determination of nitrogen in certain organic compounds containing nitrogen to nitrogen and nitrogen to oxygen linkages.One procedure gives excellent results with azo and nitro compounds, oximes, isoxazoles, hydrazines, and hydrazones, while the

Cited by 27 publications

References 9 publications

Chemiluminescence vs. Kjeldahl determination of nitrogen in oil shale retort waters and organonitrogen compounds

Chemiluminescence vs. Kjeldahl determination of nitrogen in oil shale retort waters and organonitrogen compounds

Influence of Chicken Manure Amendment on the Thermal Properties of Selected Benchmark Soils in Zambia

Determination of nitrogen in soil by the Kjeldahl method

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