A rapid method for extracting lipid components from forest litter especially adapted for ecological studies

Heng, S.; Goh, K. M.

doi:10.1080/00103628109367234

Cited by 15 publications

(5 citation statements)

References 2 publications

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“…Fats and waxes were extracted with petroleum ether (b.p. 4040°C) and determined gravimetrically by evaporating the extract to dryness ( Heng and Goh, 1981). For protein analysis samples were hydrolyzed 12 h with a 6 N HCI/1 N formic acid mixture (10/1).The a-amino nitrogen in the hydrolyzate was quantified with ninhydrine at 570 nm in a Perkin-Elmer UVNIS spectrometer (550SE) with glycine as reference ( Stevenson and Cheng, 1970).…”

Section: Methodsmentioning

confidence: 99%

Litter decomposition and humification in acidic forest soils studied by chemical degradation, IR and NMR spectroscopy and pyrolysis field ionization mass spectrometry

Hempfling

Ziegler

Zech

et al. 1987

J Plant Nutrition & Soil

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Two forest soils (Typic Dystrochrept, Entic Haplorthod) with mor and moder were investigated by chemical degradation, IR and CPMAS I3C NMR spectroscopy and pyrolysis (Py) field ionization (FI) mass spectrometry (MS). Chemical analyses show that during litter decomposition, humification, and podzolisation, cellulose and lignin structures decrease considerably, whereas no distinct changes were found for the hemicellulose and protein fractions. These results are consistent with current hypotheses on the conversion of plant residues to stable humic substances, but the sum of chemically identified organic soil components of the litter layers only accounts for 40-50% of total organic carbon. The amounts of different carbon types were estimated by the integration of CPMAS "C NMR spectra. For the L layers this calculation assigns 56-58 % as 0-alkyl-C, 20-22 % as alkyl-C, 14-16 % as aryl-C, and 6-8 % as carboxyl-C. With increasing soil depth 0-alkyl-C (with polysaccharides as main source) decrease to 31-42 %, aliphatic C increases to 3 6 4 3 %, and aryl-and carboxyl-C show no distinct changes. The hypothesis of an increasing aromaticity during humification in soils therefore is questionable. Data from Py-FIMS confirm and extend the results of chemical methods as well as IR and "CNMR spectroscopy. In particular, the FI mass spectra of the generated pyrolysates show that the increase in polymethylene carbon during the biodegradation and humification of beech and spruce litter is partly due to an increase of saturated fatty acids. This means, Py-FIMS is able to describe the structure of wet-chemically unaccounted, individual humus constituents and thus improves the knowledge about the genesis of humic substances. Humifizierung in sauren Waldhumusprofilen mit chemischem Abbau, IR und NMR Spektroskopie und Pyrolyse Feldionisation-MassenspektrometrieZwei Waldboden (Typic Dystrochrept, Entic Haplorthod) mit Rohhumus und Moder wurden chemisch, spektroskopisch (IR, CPMAS I3C NMR) und thermisch (Py-FIMS) untersucht. Die Ergebnisse der chemischen Analyse zeigen, daB wahrend der Streuzersetzung, Humifizierung und Podsolierung Cellulose und Lignin abnehmen, wahrend sich Hemicellulosen und Proteine kaum verandern. Diese Ergebnisse stimmen mit den bekannten Vorstellungen bezuglich Streuzersetzung und Humifizierung iiberein, jedoch erklart die Summe der chemisch identifizierten organischen Bodeninhaltsstoffe der Streulagen nur 40-50 % des gesamten organischen Kohlenstoffs. Die Summe der verschiedenen Bindungsformen des Kohlenstoffs wurde durch Integration der I3C NMR Spektren errechnet. Fur die L-Lagen gilt: 56-58 % 0-Alkyl-C, 20-22 % Alkyl-C, 14-16 % Aryl-C und 6-8 % Carboxyl-C. Mit zunehmender Bodentiefe nehmen die Polysaccharide auf 31-42 % ab, der Aliphatenanteil steigt auf 3 6 4 3 %, Aryl-C und Carboxyl-C zeigen keine deutlichen Veranderungen. Die Hypothese der zunehmenden Aromatisierung wahrend der Humifizierung in Boden wird dadurch grundsatzlich in Frage gestellt. Die Ergebnisse der Py-FIMS bestatigen und erweitern sowohl die che...

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Section: Methodsmentioning

confidence: 99%

Litter decomposition and humification in acidic forest soils studied by chemical degradation, IR and NMR spectroscopy and pyrolysis field ionization mass spectrometry

Hempfling

Ziegler

Zech

et al. 1987

J Plant Nutrition & Soil

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“…An aliquot was heated at 550°C overnight to determine the ash content. Nonpolar extractives were determined using extraction in a dichloromethane solution (Heng and Goh 1981;McClaugherty et al 1985;Ryan et al 1990); watersoluble extractives were determined using hot water (100°C) extraction (TAPPI 1999); and acid-soluble as well as acid-insoluble fractions were determined using a two-stage digestion in sulfuric acid (Effland 1977). The proximate fractions (i.e.…”

Section: Proximate Fractionation and Isotopic Analysismentioning

confidence: 99%

Chemical composition of forest floor and consequences for nutrient availability after wildfire and harvesting in the boreal forest

et al. 2008

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In boreal forests of eastern Canada, wildfire has gradually been replaced by clearcut harvesting as the most extensive form of disturbance. Such a shift in disturbance may influence the chemical properties of the forest floor and its capacity to cycle and supply nutrients, with possible implications for forest productivity. We compared the effects of stem-only harvesting (SOH), whole-tree harvesting (WTH) and wildfire on the chemical composition of forest floor organic matter and nutrient availability for plants, 15-20 years after disturbance in boreal coniferous stands in Quebec (Canada). The forest floor on plots of wildfire origin was significantly enriched in aromatic forms of C with low solubility, whereas the forest floor from SOH and WTH plots was enriched with more soluble and labile C compounds. The forest floor of wildfire plots was also characterized by higher N concentration, but its high C:N and high concentration of 15 N suggest that its N content could be recalcitrant and have a slow turnover rate. Total and exchangeable K were associated with easily degradable organic structures, whereas total and exchangeable Ca and Mg were positively correlated with the more recalcitrant forms of C. We suggest that the bulk of Ca and Mg cycling in the soil-plant system is inherited from the influx of exchangeable cations in the forest floor following disturbance. The buildup of Ca and Mg exchangeable reserves should be greater with wildfire than with harvesting, due to the sudden pulse of cation-rich ash and to the deposition of charred materials with high exchange capacity. This raises uncertainties about the long-term availability of Ca and Mg for plant uptake on harvested sites. In contrast, K availability should not be compromised by either harvesting or wildfire since it could be recycled rapidly through vegetation, litter and labile organic compounds.

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“…Lignin has been estimated by quantification of the products of CuO oxidation (Hedges and Ertel 1982;Reeves 1995) and tetramethylammonium hydroxide thermochemolysis (Hatcher et al 1995;Baldock et al 1997a). A variety of organic solvents and solvent mixes have been used to extract and quantify various lipid fractions (Heng and Goh 1981;Ma'shum et al 1988;Wu et al 1995). Several of these specific extraction techniques can be combined, as in the proximate-analysis approach, in an attempt to completely define the molecular composition of organic materials (Preston et al 1997).…”

Section: Introductionmentioning

confidence: 99%

Estimating the molecular composition of a diverse range of natural organic materials from solid-state 13C NMR and elemental analyses

2005

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Most techniques for determining the chemical nature of natural organic matter in soil, sediment and water require prior extraction or concentration steps that are not quantitative and that create artifacts. 13 C nuclear magnetic resonance (NMR) analysis can avoid these problems, but it gives little information at the scale of molecules. Here we show that the molecular composition of a diverse range of natural organic materials could be inferred from 13 C NMR analysis combined with C and N analysis. Forty-six different organic materials including undecomposed and decomposed plant materials, soil organic matter, phytoplankton, and the organic matter found in freshwater, estuarine and marine sediments were examined. A mixing model simultaneously solved a series of equations to estimate the content of four biomolecule components representing the organic materials produced in greatest abundance by plants and other organisms (carbohydrate, protein, lignin and aliphatic material) and two additional components (char and pure carbonyl). Based on defined molecular structures for each component, signal intensities for 13 C NMR spectra were predicted and compared with measured values. The sum of the absolute differences in signal intensity between the measured and predicted spectral regions was <7% for the terrestrial materials. For aquatic materials the fit of the predicted to measured signal intensities was not as good. Predicted molecular compositions correlated well with independent analyses of cellulose, protein and lignin contents of plant samples and char contents of soil samples. Across all samples, carbohydrates accounted for 10-76% of the sample C (40-76% in plants and 10-42% in soils, sediments and phytoplankton), protein for 2-80% (21-80% in phytoplankton and marine water column samples and 2-36% in plants, soils and sediments), lignin for 0-36%, aliphatic materials for 2-44%, char for 0-38% and carbonyl for 0-22%. For the soils, sediments and decomposed plant materials, the close correspondence between actual signal intensities and those predicted using known biomolecular components, suggested that either 'humic' structures can be approximated by mixtures of common biologically derived molecules or that humic structures did not exist in significant amounts.Abbreviations: CP -cross-polarisation; DP -Direct polarisation; MAS -magic-angle-spinning; NMRnuclear magnetic resonance; UV NMR -ultra-violet photo-oxidation of the <53lm fraction followed by 13 C NMR analysis

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A rapid method for extracting lipid components from forest litter especially adapted for ecological studies

Cited by 15 publications

References 2 publications

Litter decomposition and humification in acidic forest soils studied by chemical degradation, IR and NMR spectroscopy and pyrolysis field ionization mass spectrometry

Litter decomposition and humification in acidic forest soils studied by chemical degradation, IR and NMR spectroscopy and pyrolysis field ionization mass spectrometry

Chemical composition of forest floor and consequences for nutrient availability after wildfire and harvesting in the boreal forest

Estimating the molecular composition of a diverse range of natural organic materials from solid-state 13C NMR and elemental analyses

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