Pyrolysis gas chromatography atomic emission detection method for determination of N-containing components of humic and fulvic acids

Song, Xianzhi; Farwell, S. O.

doi:10.1016/j.jaap.2003.12.002

Cited by 22 publications

(21 citation statements)

References 28 publications

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“…It has been used frequently as a threshold value of the NLO parameters. As can be noted, the values of all parameters for the compounds studied here are greater than those values found for the urea parameters (µ = 1.37D, α = 3.83 × 10 −24 esu, and γ = 4.16 × 10 −36 esu) [37][38][39]. When our results are compared with those of urea, compound I is 3.1 times greater for the dipole moment, 8.8 times greater for the average linear polarizability and 20.5 times greater for the second hyperpolarizability, while compound II is 2.3 times larger for the dipole moment, 9.0 times greater for linear polarizability, and 19.5 times greater for the average value of the second hyperpolarizability.…”

Section: Resultscontrasting

confidence: 57%

Effects of Changing Substituents on the Non-Linear Optical Properties of Two Coumarin Derivatives

et al. 2017

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Abstract:In this article, we study the electric properties of two coumarin derivatives whose difference stems from the change of substituents at 3-position of the pendant benzene ring (C 18 H 15 NO 3 ) and (C 18 H 15 NO 4 ). We use the supermolecule approach to deal with the molecules under the effect of the crystalline environment to calculate dipole moment, linear polarizability, and second-order hyperpolarizability, for the isolated and embedded molecules, including the static and dynamic cases and the presence of solvents. The (hyper) polarizabilities were derived from an iterative process and an ab initio computational procedure. In addition, we also calculated the HOMO-LUMO energies; at this point, the objective is to verify the effect of the exchange of substituents on the Band-Gap energy, an important parameter related to the excitation properties of coumarin compounds.

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Section: Resultscontrasting

confidence: 57%

Effects of Changing Substituents on the Non-Linear Optical Properties of Two Coumarin Derivatives

et al. 2017

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“…Analytical pyrolysis has been increasingly used for characterizing the chemical structure of soil organic N (Leinweber et al 1995;Schulten et al 1997;Schulten and Schnitzer 1998;Song and Farwell 2004). Schulten et al (1997) and Schulten and Schnitzer (1998) used pyrolysis-field ionization-mass spectrometry (Py-FIMS) and pyrolysisgas chromatography-mass spectrometry (Py-GC-MS) to identify N compounds in the whole soil and in hydrolyzates and hydrolysis residues resulting from acid hydrolysis of mineral soils and to determine the origin of these compounds.…”

Section: Pyrolysis-mass Spectrometrymentioning

confidence: 99%

Analysis and behavior of soluble organic nitrogen in forest soils

Chen

2008

J Soils Sediments

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Background, aim, and scope A large proportion of soil nitrogen (N; >80%) is present in organic form. Current research on plant N uptake in terrestrial ecosystems has focused mainly on inorganic N such as ammonium (NH 4 + ) and nitrate (NO 3 − ), while soluble organic N (SON) has received little attention. In recent years, the increasing evidence showing the direct uptake of various amino acids by plants and the predominance of the organic form in N loss by leaching in many forest ecosystems has drawn attention to critically re-examine the nature and the ecological role of soil SON in terrestrial N cycling. However, little is known about the sources and dynamics, chemical nature, and ecological functions of soil SON in forest ecosystems. This paper reviews recent advances in the areas of research on current techniques for characterizing soil SON and the size, nature, and dynamics of soil SON pools in forest ecosystems. Materials and methods The SON represents a significant pool of available and mobile N in forest soils. The SON can be sampled using a number of physical (e.g., suction cup, microdialysis) and chemical (e.g., extraction) methods and analyzed by the wet chemistry method (e.g., persulfate oxidation) and combustion. Chemical and physical fractionation, pyrolysis-mass spectrometry, 13 C and 15 N nuclear magnetic resonance spectroscopy, and 15 N, 13 C, and 14 C isotopic techniques have been used for investigating the nature and dynamics of SON in forest ecosystems. Results and discussion The amount of SON in soil may vary with land use type, forest species, management practices, and analytical procedures used. Statistical figures, based on 116 datasets available in the literature, have shown that concentrations of soil SON can range from 1 mg N kg −1 (dry weight basis) to up to 448 mg N kg −1 , with an average of 35 mg N kg −1 , representing an average of 48% of total soluble N. Soil SON consists of a mixture of structurally diverse N-containing compounds, possibly with the amide N, amino acids, and amino sugars being predominant. The biodegradability of SON largely depends upon its chemical characteristics (e.g., C-to-N ratio). Conclusions Direct utilization of added amino acids by a large number of forest species may present a potentially important new pathway for plant N uptake. However, the evidence of direct utilization of soil native SON by forest plants is still lacking, and the extent of the contribution of SON to forest plants is far from certain. Transformation of soil organic matter into SON, rather than the conversion of SON to NH 4 + /NO 3 − , may be the rate-limiting step, which regulates the overall N cycling in N-limited forest ecosystems.Recommendations and perspectives Future work may well focus on the chemical and biological nature of SON in forest soils, microbial transformation of SON, the nutritional role of the SON pools in the N-limited forest ecosystems, and the potential role of SON in global climate change (e.g., N 2 O emission).

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“…Acetamide has been noted as a pyrolysis product of both bacteria [44] and humic substances [45][46][47]. Acetamide has been shown to be the predominant pyrolysis product of peptidoglycan, a primary component of bacterial cell walls [44].…”

Section: Py-gc-ms Of Little Lost River Cave Materialsmentioning

confidence: 99%

“…Acetamide has been shown to be the predominant pyrolysis product of peptidoglycan, a primary component of bacterial cell walls [44]. Song and Farwell [45] and Schulten and Schnitzer [46] have observed acetamide in the pyrolysis of humic material. Acetamide has been shown to result from the pyrolysis of various amino acids contained within humic soils.…”

Section: Py-gc-ms Of Little Lost River Cave Materialsmentioning

confidence: 99%

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Pyrolysis GC–MS and THM-GC–MS studies of a black coating from Little Lost River Cave, Idaho

Fezzey

Armitage

2006

Journal of Analytical and Applied Pyrolysis

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Pyrolysis gas chromatography atomic emission detection method for determination of N-containing components of humic and fulvic acids

Cited by 22 publications

References 28 publications

Effects of Changing Substituents on the Non-Linear Optical Properties of Two Coumarin Derivatives

Effects of Changing Substituents on the Non-Linear Optical Properties of Two Coumarin Derivatives

Analysis and behavior of soluble organic nitrogen in forest soils

Pyrolysis GC–MS and THM-GC–MS studies of a black coating from Little Lost River Cave, Idaho

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