Solid-state 13C NMR analysis of size and density fractions of marine sediments: Insight into organic carbon sources and preservation mechanisms

Dickens, Angela F.; Baldock, J. A.; Smernik, Ronald J.; Wakeham, Stuart G.; Arnarson, Thórarinn S.; Gélinas, Yves; Hedges, John I.

doi:10.1016/j.gca.2005.10.024

Cited by 83 publications

(79 citation statements)

References 85 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A relationship between the S/N of the CPMG spike (S/N SS ) and the number of scans required in a conventional 13 C CP experiment to achieve a specific S/N (NS CP ) can be determined. In any conventional NMR experiment, the S/N is directly proportional to the square root of the number of scans, the amount of sample (n), and various other spectrometer and environmental conditions, which are generally kept constant (k), as shown in Equation 1 [38].…”

Section: Proof Of Principlementioning

confidence: 99%

“…Recording NMR spectra is often challenging in part because the nuclei are relatively insensitive and in part because of the wide range of chemical environments present in heterogeneous environmental samples. To demonstrate that the CPMG-SS approach is not limited to 13 C, 31 P NMR was performed on a freeze-dried worm. Figure 5A (left) displays the CPMG-SS spike and corresponding 31 P CP experiment for a freeze-dried worm.…”

Section: Very-low-abundance Samplesmentioning

confidence: 99%

“…In particular, cross-polarization magic angle spinning (CP/MAS) experiments have been used extensively because of the qualitative structural information that is gained and because of its nondestructive nature [12]. Cross-polarization magic angle spinning is now routinely used in environmental studies on a variety of samples, including natural organic matter, wood, sediments, and black carbon [13][14][15][16]. In most cases, 13 C is the nucleus of interest, which yields an overall profile of the organic composition of the sample; however, studies involving CP/MAS of other nuclei such as 15 N and 31 P also have wide environmental application [17,18].…”

Section: Introductionmentioning

confidence: 99%

“…Such treatments can take months and, when the organic carbon content is low, can consume a large amount of the original sample to produce the 100 mg required for common solid-state NMR analysis. Carbon combustion analysis may be performed to determine sufficient carbon content in a sample and helps determine whether 13 C NMR analysis is feasible. However, in many cases, there is simply not enough material to permit accurate carbon analysis by combustion, which requires approximately 5 g per measurement (for samples <10% organic carbon) and should be performed in triplicate, which would require 15 g total [21].…”

Section: Introductionmentioning

confidence: 99%

“…Lim et al [25] use the single-spike technique to enhance multiple quantum NMR experiments. In the present study, the use of the CPMG single spike (CPMG-SS) spectroscopy to predict whether a sample will yield an adequate spectrum is demonstrated, and how the intensity of the CPMG spike correlates with the time required to obtain a full 13 C NMR spectrum of a particular S/N is evaluated. To illustrate the approach, the present study analyzes several environmental samples in solid-and liquid-state NMR, and its use in 13 …”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Rapid estimation of nuclear magnetic resonance experiment time in low‐concentration environmental samples

Masoom

Courtier‐Murias

Farooq

et al. 2012

Enviro Toxic and Chemistry

View full text Add to dashboard Cite

Abstract-Nuclear magnetic resonance (NMR) spectroscopy is an essential tool for studying environmental samples but is often hindered by low sensitivity, especially for the direct detection of nuclei such as 13 C. In very heterogeneous samples with NMR nuclei at low abundance, such as soils, sediments, and air particulates, it can take days to acquire a conventional 13 C spectrum. The present study describes a prescreening method that permits the rapid prediction of experimental run time in natural samples. The approach focuses the NMR chemical shift dispersion into a single spike, and, even in samples with extremely low carbon content, the spike can be observed in two to three minutes, or less. The intensity of the spike is directly proportional to the total concentration of nuclei of interest in the sample. Consequently, the spike intensity can be used as a powerful prescreening method that answers two key questions: (1) Will this sample produce a conventional NMR spectrum? (2) How much instrument time is required to record a spectrum with a specific signal-tonoise (S/N) ratio? The approach identifies samples to avoid (or pretreat) and permits additional NMR experiments to be performed on samples producing high-quality NMR data. Applications in solid-and liquid-state 13 C NMR are demonstrated, and it is shown that the technique is applicable to a range of nuclei. Environ. Toxicol. Chem. 2013;32:129-136. # 2012 SETAC

show abstract

Section: Proof Of Principlementioning

confidence: 99%

Section: Very-low-abundance Samplesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Rapid estimation of nuclear magnetic resonance experiment time in low‐concentration environmental samples

Masoom

Courtier‐Murias

Farooq

et al. 2012

Enviro Toxic and Chemistry

View full text Add to dashboard Cite

show abstract

A multiproxy analysis of sedimentary organic carbon in the Changjiang Estuary and adjacent shelf

Yao

Bianchi

et al. 2015

JGR Biogeosciences

View full text Add to dashboard Cite

Surface sediments from the Changjiang Estuary and adjacent shelf were analyzed using a variety of bulk and molecular techniques, including grain size composition, sediment surface area (SSA), elemental composition (C, N), stable carbon isotopic composition (δ 13 C), n-alkanes, lignin phenols, and glycerol dialkyl glycerol tetraether lipids to obtain a more comprehensive understanding of the sources and fate of sedimentary organic carbon (SOC) in this dynamic region. Bulk N/C ratios of 0.09 to 0.15, δ 13 C of À24.4‰ to À21.1‰, branched/isoprenoid tetraether index of 0 to 0.74, n-alkane content of 0.02 to 0.37 mg g À1 organic carbon (OC), and lignin content (Λ 8 ) of 0.10 to 1.46 mg/100 mg OC and other related molecular indices in these samples indicate a mixed source of marine, soil, and terrestrial plant-derived OC in the study area. A three-end-member mixing model using principal component analysis (PCA) factors as source markers and based on Monte Carlo (MC) simulation was constructed to estimate the relative contributions of OC from different sources. Compared with traditional mixing models, commonly based on a few variables, this newly developed PCA-MC model supported bulk and biomarker data and yielded a higher-resolution OC inputs to different subregions of this system. In particular, the results showed that the average contributions of marine, soil, and terrestrial OC in the study area were 35.3%, 47.0%, and 17.6%, and the highest contribution from each OC source was mainly observed in the shelf, inner estuary, and coastal region, respectively.

show abstract

Partitioning of organic carbon among density fractions in surface sediments of Fiordland, New Zealand

et al. 2016

View full text Add to dashboard Cite

Transport of particles plays a major role in redistributing organic carbon (OC) along coastal regions. In particular, the global importance of fjords as sites of carbon burial has recently been shown to be even more important than previously thought. In this study, we used six surface sediments from Fiordland, New Zealand, to investigate the transport of particles and OC based on density fractionation. Bulk, biomarker, and principle component analysis were applied to density fractions with ranges of <1.6, 1.6-2.0, 2.0-2.5, and >2.5 g cm À3 . Our results found various patterns of OC partitioning at different locations along fjords, likely due to selective transport of higher density but smaller size particles along fjord head-to-mouth transects. We also found preferential leaching of certain biomarkers (e.g., lignin) over others (e.g., fatty acids) during the density fractionation procedure, which altered lignin-based degradation indices. Finally, our results indicated various patterns of OC partitioning on density fractions among different coastal systems. We further propose that a combination of particle size-density fractionation is needed to better understand transport and distribution of particles and OC.

show abstract

Solid-state 13C NMR analysis of size and density fractions of marine sediments: Insight into organic carbon sources and preservation mechanisms

Cited by 83 publications

References 85 publications

Rapid estimation of nuclear magnetic resonance experiment time in low‐concentration environmental samples

Rapid estimation of nuclear magnetic resonance experiment time in low‐concentration environmental samples

A multiproxy analysis of sedimentary organic carbon in the Changjiang Estuary and adjacent shelf

Partitioning of organic carbon among density fractions in surface sediments of Fiordland, New Zealand

Contact Info

Product

Resources

About