Molecular organic geochemistry of New York Bight sediments: Sources of biogenic organic matter and polycyclic aromatic hydrocarbons

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

As part of a multidisciplinary evaluation of the environmental impact of waste disposal in the New York Bight, a preliminary effort was undertaken to assess the molecular geochemistry of its sedimentary organic matter (OM). For this initial phase of the study, samples were taken from two New York Bight cores collected outside the area of known dumping, to establish the environmental context for future work on sediments from within dumpsite zones. The method employed was flash pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), which is an organic microanalysis technique suitable for solid samples, in this case dried, raw sediment. The resulting pyrolyzates show a predominance of (alkyl)benzenes, (alkyl)phenols, (alkyl)pyridines, and (alkyl)pyrroles, indicating that the bulk of the OM detected is of recent, biogenic origin. The OM includes degraded proteinaceous material, polysaccharides, lipids and higher plant waxes. While the OM is nominally 'natural', this interpretation does not exclude the possibility that the environment may have been perturbed by anthropogenically-enhanced nutrient fluxes. Samples taken deeper in the cores are relatively enriched in organic nitrogen and have more pyridinic nitrogen relative to pyrrolic. Thus the relative amounts and forms of organic nitrogen appear to be affected by diagenetic processes. In addition to its ability to characterize the bulk OM, Py-GC/MS of whole, dry sediment has been shown to be a useful tool for the rapid, semi-quantitative screening for trace concentrations of PAHs in potentially contaminated samples. The PAH data indicate that, while the majority of the OM is biogenic, there is a contribution of combustion-derived material, particularly in the upper samples from both cores. Molecular ratios employing key compounds may provide insights into the nature of the depositional environment. For example, considering the five-ring PAHs, a predominance of perylene over benzofluoranthenes and benzopyrenes is characteristic of pristine (i.e., pre-industrial era) sediments, as seen in the deepest sample examined in this study (175-200 cm sediment depth).

Original languageEnglish
Pages (from-to)121-128
Number of pages8
JournalNortheastern Geology and Environmental Sciences
Volume21
Issue number1-2
StatePublished - 1 Jan 1999

Fingerprint

organic geochemistry
Geochemistry
Polycyclic aromatic hydrocarbons
Biological materials
PAH
Sediments
organic matter
sediment
organic nitrogen
Nitrogen
Gas chromatography
pyrolysis
Mass spectrometry
gas chromatography
Pyrolysis
mass spectrometry
Microanalysis
Waxes
Polysaccharides
wax

Cite this

@article{35bbac93306542599e9174f3321f4d4a,
title = "Molecular organic geochemistry of New York Bight sediments: Sources of biogenic organic matter and polycyclic aromatic hydrocarbons",
abstract = "As part of a multidisciplinary evaluation of the environmental impact of waste disposal in the New York Bight, a preliminary effort was undertaken to assess the molecular geochemistry of its sedimentary organic matter (OM). For this initial phase of the study, samples were taken from two New York Bight cores collected outside the area of known dumping, to establish the environmental context for future work on sediments from within dumpsite zones. The method employed was flash pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), which is an organic microanalysis technique suitable for solid samples, in this case dried, raw sediment. The resulting pyrolyzates show a predominance of (alkyl)benzenes, (alkyl)phenols, (alkyl)pyridines, and (alkyl)pyrroles, indicating that the bulk of the OM detected is of recent, biogenic origin. The OM includes degraded proteinaceous material, polysaccharides, lipids and higher plant waxes. While the OM is nominally 'natural', this interpretation does not exclude the possibility that the environment may have been perturbed by anthropogenically-enhanced nutrient fluxes. Samples taken deeper in the cores are relatively enriched in organic nitrogen and have more pyridinic nitrogen relative to pyrrolic. Thus the relative amounts and forms of organic nitrogen appear to be affected by diagenetic processes. In addition to its ability to characterize the bulk OM, Py-GC/MS of whole, dry sediment has been shown to be a useful tool for the rapid, semi-quantitative screening for trace concentrations of PAHs in potentially contaminated samples. The PAH data indicate that, while the majority of the OM is biogenic, there is a contribution of combustion-derived material, particularly in the upper samples from both cores. Molecular ratios employing key compounds may provide insights into the nature of the depositional environment. For example, considering the five-ring PAHs, a predominance of perylene over benzofluoranthenes and benzopyrenes is characteristic of pristine (i.e., pre-industrial era) sediments, as seen in the deepest sample examined in this study (175-200 cm sediment depth).",
author = "Michael Kruge",
year = "1999",
month = "1",
day = "1",
language = "English",
volume = "21",
pages = "121--128",
journal = "Northeastern Geology and Environmental Sciences",
issn = "0194-1453",
publisher = "Allen Press Inc.",
number = "1-2",

}

TY - JOUR

T1 - Molecular organic geochemistry of New York Bight sediments

T2 - Sources of biogenic organic matter and polycyclic aromatic hydrocarbons

AU - Kruge, Michael

PY - 1999/1/1

Y1 - 1999/1/1

N2 - As part of a multidisciplinary evaluation of the environmental impact of waste disposal in the New York Bight, a preliminary effort was undertaken to assess the molecular geochemistry of its sedimentary organic matter (OM). For this initial phase of the study, samples were taken from two New York Bight cores collected outside the area of known dumping, to establish the environmental context for future work on sediments from within dumpsite zones. The method employed was flash pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), which is an organic microanalysis technique suitable for solid samples, in this case dried, raw sediment. The resulting pyrolyzates show a predominance of (alkyl)benzenes, (alkyl)phenols, (alkyl)pyridines, and (alkyl)pyrroles, indicating that the bulk of the OM detected is of recent, biogenic origin. The OM includes degraded proteinaceous material, polysaccharides, lipids and higher plant waxes. While the OM is nominally 'natural', this interpretation does not exclude the possibility that the environment may have been perturbed by anthropogenically-enhanced nutrient fluxes. Samples taken deeper in the cores are relatively enriched in organic nitrogen and have more pyridinic nitrogen relative to pyrrolic. Thus the relative amounts and forms of organic nitrogen appear to be affected by diagenetic processes. In addition to its ability to characterize the bulk OM, Py-GC/MS of whole, dry sediment has been shown to be a useful tool for the rapid, semi-quantitative screening for trace concentrations of PAHs in potentially contaminated samples. The PAH data indicate that, while the majority of the OM is biogenic, there is a contribution of combustion-derived material, particularly in the upper samples from both cores. Molecular ratios employing key compounds may provide insights into the nature of the depositional environment. For example, considering the five-ring PAHs, a predominance of perylene over benzofluoranthenes and benzopyrenes is characteristic of pristine (i.e., pre-industrial era) sediments, as seen in the deepest sample examined in this study (175-200 cm sediment depth).

AB - As part of a multidisciplinary evaluation of the environmental impact of waste disposal in the New York Bight, a preliminary effort was undertaken to assess the molecular geochemistry of its sedimentary organic matter (OM). For this initial phase of the study, samples were taken from two New York Bight cores collected outside the area of known dumping, to establish the environmental context for future work on sediments from within dumpsite zones. The method employed was flash pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), which is an organic microanalysis technique suitable for solid samples, in this case dried, raw sediment. The resulting pyrolyzates show a predominance of (alkyl)benzenes, (alkyl)phenols, (alkyl)pyridines, and (alkyl)pyrroles, indicating that the bulk of the OM detected is of recent, biogenic origin. The OM includes degraded proteinaceous material, polysaccharides, lipids and higher plant waxes. While the OM is nominally 'natural', this interpretation does not exclude the possibility that the environment may have been perturbed by anthropogenically-enhanced nutrient fluxes. Samples taken deeper in the cores are relatively enriched in organic nitrogen and have more pyridinic nitrogen relative to pyrrolic. Thus the relative amounts and forms of organic nitrogen appear to be affected by diagenetic processes. In addition to its ability to characterize the bulk OM, Py-GC/MS of whole, dry sediment has been shown to be a useful tool for the rapid, semi-quantitative screening for trace concentrations of PAHs in potentially contaminated samples. The PAH data indicate that, while the majority of the OM is biogenic, there is a contribution of combustion-derived material, particularly in the upper samples from both cores. Molecular ratios employing key compounds may provide insights into the nature of the depositional environment. For example, considering the five-ring PAHs, a predominance of perylene over benzofluoranthenes and benzopyrenes is characteristic of pristine (i.e., pre-industrial era) sediments, as seen in the deepest sample examined in this study (175-200 cm sediment depth).

UR - http://www.scopus.com/inward/record.url?scp=0032775723&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0032775723

VL - 21

SP - 121

EP - 128

JO - Northeastern Geology and Environmental Sciences

JF - Northeastern Geology and Environmental Sciences

SN - 0194-1453

IS - 1-2

ER -