@article {457,
	title = {A radiocarbon-based assessment of the preservation characteristics of crenarchaeol and alkenones from continental margin sediments},
	journal = {Organic Geochemistry},
	volume = {39},
	year = {2008},
	note = {id: 883; 344AQ Times Cited:11 Cited References Count:33Y},
	pages = {1039-1045},
	abstract = {Crenarchaeotal glycerol dibiphytanyl glycerol tetraether (GDGT) lipids and alkenones are two types of biomarkers, derived from planktonic marine microorganisms, which are used for reconstruction of sea surface temperature. We determined the radiocarbon contents of the archaeal GDGT crenarchaeol and of alkenones isolated from continental margin sediments. Systematic differences were found between the two biomarkers, with higher radiocarbon content in crenarchaeol than in the phytoplankton-derived alkenones. These differences can be explained by variable contributions of pre-aged, laterally-advected material to the core sites. Crenarchaeol appears to be more efficiently degraded during transport in oxygen-replete environments than alkenones. Whether this reflects the influence of chemical structure or mode of protection (e.g., particle association) is not known. (C) 2008 Elsevier Ltd. All rights reserved.},
	issn = {0146-6380},
	doi = {10.1016/J.Orggeochem.2008.02.006},
	author = {Mollenhauer, G. and Eglinton, T. I. and HopmanSd, E. C. and Damste, J. S. S.}
}
@conference {1762,
	title = {Radiocarbon and Th-230 data reveal temperal changes in sediment focusing at ODP site 984, Poster},
	booktitle = {EGU General Assembly},
	year = {2007},
	note = {id: 547},
	month = {2007},
	address = {Vienna, Austria},
	author = {Mollenhauer, Gesine and McManus, J. F. and Wagner, T. and McCave, I. N. and Eglinton, T. I.}
}
@article {1977,
	title = {Radiocarbon dating of alkenones from marine sediments: I. Isolation protocol},
	journal = {Radiocarbon},
	volume = {47},
	year = {2005},
	note = {993nkTimes Cited:13
Cited References Count:22
},
	month = {2005},
	pages = {401-412},
	abstract = {The chemical and isotopic compositions of long-chain (C-36-C-39) unsaturated ketones (alkenones), a unique class of algal lipids, encode surface ocean properties useful for paleoceanographic reconstruction. Recently, we have sought to extend the utility of alkenones as oceanic tracers through measurement of their radiocarbon contents. Here. we describe a method for isolation of alkenones from sediments as a compound class based on a sequence of wet chemical techniques. The steps involved, which include silica gel column chromatography, urea adduction, and silver nitrate-silica gel column chromatography, exploit various structural attributes of the alkenones. Amounts of purified alkenones estimated by GC/FID measurements were highly correlated with CO2 yields after sample combustion, indicating purities of greater than 90\% for samples containing >= 100 mu g C. The degree of alkenone unsaturation (U-37(K{\textquoteright})) also varied minimally through the procedure. We also describe a high-performance liquid chromatography (HPLC) method to isolate individual alkenones for molecular-level structural and isotopic determination.},
	keywords = {AMS, carbon, indicators, proxy, records, tool},
	isbn = {0033-8222},
	author = {Ohkouchi, N. and Xu, L. and Reddy, C. M. and Montlucon, D. and Eglinton, T. I.}
}
@article {1980,
	title = {Radiocarbon dating of alkenones from marine sediments: II. Assessment of carbon process blanks},
	journal = {Radiocarbon},
	volume = {47},
	year = {2005},
	note = {993nkTimes Cited:13
Cited References Count:20
},
	month = {2005},
	pages = {413-424},
	abstract = {We evaluate potential process blanks associated with radiocarbon measurement of microgram to milligram quantities of alkenones at the National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) facility. Two strategies to constrain the contribution of blanks to alkenone C-14 dates were followed: 1) dating of samples of known age and 2) multiple measurements of identical samples. We show that the potential contamination associated with the procedure does not lead to a systematic bias of the results of alkenone dating to either younger or older ages. Our results indicate that alkenones record Delta(14)C of ambient DIC with an accuracy of approximately 10 parts per thousand. A conservative estimate of measurement precision is 17 parts per thousand for modern samples. Alkenone C-14 ages are expected to be reliable within 500 yr for samples younger than 10,500 C-14 yr.},
	keywords = {c-14 ams, organic-compounds, records, samples, system, tool},
	isbn = {0033-8222},
	author = {Mollenhauer, G. and Montlucon, D. and Eglinton, T. I.}
}
@article {1978,
	title = {Radiocarbon dating of alkenones from marine sediments-III. Influence of solvent extractions procedures on 14C measurements of foraminifera},
	journal = {Radiocarbon},
	volume = {47},
	year = {2005},
	note = {id: 554},
	month = {2005},
	pages = {425-432},
	author = {Ohkouchi, N. and Eglinton, T. I. and Hughen, K. A. and Roosen, E. and Keigwin, L.}
}
@conference {1773,
	title = {Rapid lateral particle transport in the Argintine Basin: Th-230 and molecular C-14 Evidence, Poster},
	booktitle = {EGU General Assembly},
	year = {2005},
	note = {id: 548},
	month = {2005},
	address = {Vienna, Austria},
	author = {Mollenhauer, Gesine and McManus, J. F. and Benthien, A. and Muller, P. J. and Eglinton, T. I.}
}
@article {2027,
	title = {Radiocarbon evidence for a naturally-produced, bioaccumulation halogenated organic compound},
	journal = {Environmental Science and Technology},
	volume = {38},
	year = {2004},
	note = {id: 1806},
	month = {2004},
	pages = {1992-1997},
	author = {Reddy, C. M. and Xu, L. and O{\textquoteright}Neil, G. W. and Nelson, R. K. and Eglinton, T. I. and Faulkner, D. J. and Norstrom, R. and Ross, P. S. and Tittlemier, S. A.}
}
@article {2073,
	title = {Radiocarbon dating of individual fatty acids as a tool for refining Antarctic margin sediment chronologies},
	journal = {Radiocarbon},
	volume = {45},
	year = {2003},
	note = {735tqTimes Cited:25
Cited References Count:29
},
	month = {2003},
	pages = {17-24},
	abstract = {We have measured the radiocarbon contents of individual, solvent-extractable, short-chain (C-14, C-16, and C-18) fatty acids isolated from Ross Sea surface sediments. The corresponding C-14 ages are equivalent to that of the post-bomb dissolved inorganic carbon (DIC) reservoir. Moreover, molecular C-14 variations in surficial (upper 15 cm) sediments indicate that these compounds may prove useful for reconstructing chronologies of Antarctic margin sediments containing uncertain (and potentially variable) quantities of relict organic carbon. A preliminary molecular C-14 chronology suggests that the accumulation rate of relict organic matter has not changed during the last 500 C-14 yr. The focus of this study is to determine the validity of compound-specific C-14 analysis as a technique for reconstructing chronologies of Antarctic margin sediments.},
	keywords = {carbon, ice-sheet, marine-sediments, north-atlantic, organic-matter, ross-sea, southern-ocean},
	isbn = {0033-8222},
	author = {Ohkouchi, N. and Eglinton, T. I. and Hayes, J. M.}
}
@article {637,
	title = {Radiocarbon as a tool to apportion the sources of polycyclic aromatic hydrocarbons and black carbon in environmental samples},
	journal = {Environmental Science \& Technology},
	volume = {36},
	year = {2002},
	note = {541gfTimes Cited:133Cited References Count:59},
	month = {Apr 15},
	pages = {1774-1782},
	abstract = {To determine the relative inputs of polycyclic aromatic hydrocarbons (PAHs) and black carbon (BC) in environmental samples from the combustion of fossil fuels and biomass we have developed two independent analytical methods for determining the C-14 abundance of PAHs and BC. The 5730 yr half-life of C-14 makes it an ideal tracer for identifying combustion products derived from fossil fuels (C-14-free) versus those stemming from modern biomass (contemporary C-14). The C-14 abundance of PAHs in several environmental Standard Reference Materials was measured by accelerator mass spectrometry after extraction and then purification by high-performance liquid chromatography and preparative capillary gas chromatography. This method yields pure compounds that allow for a high degree of confidence in the C-14 results. The PAHs data were then used to compare and evaluate results from an operationally defined thermal oxidation method used to isolate a BC fraction. The C-14 compositions of PAHs and BC were very similar and suggest that the thermal oxidation method employed for isolating BC is robust and free from interferences by non-BC components. In addition, these data indicate that both the PAHs and the BC species derive mostly from fossil fuels and/or their combustion products.},
	issn = {0013-936x},
	doi = {10.1021/es011343f},
	author = {Reddy, C. M. and Pearson, A. and Xu, L. and McNichol, A. P. and Benner, B. A. and Wise, S. A. and Klouda, G. A. and Currie, L. A. and Eglinton, T. I.}
}
@article {2103,
	title = {Radiocarbon content of synthetic and natural semi-volatile halogenated organic compounds},
	journal = {Environ Pollut},
	volume = {120},
	year = {2002},
	note = {Reddy, Christopher MXu, Li
Eglinton, Timothy I
Boon, Jan P
Faulkner, D John
eng
Research Support, Non-U.S. Gov{\textquoteright}t
Research Support, U.S. Gov{\textquoteright}t, Non-P.H.S.
England
2002/10/25 04:00
Environ Pollut. 2002;120(2):163-8.
},
	month = {2002},
	pages = {163-8},
	abstract = {Some halogenated organic compounds, such as polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs) and polybrominated diphenyl ethers (PBDEs), have been suggested to have natural sources but separating these compounds from their commercially synthesized counterparts is difficult. Molecular-level 14C analysis may be beneficial since most synthetic compounds are manufactured from petrochemicals (14C-free) and natural compounds should have "modern" or "contemporary" 14C levels. As a baseline study, we measured, for the first time, the 14C abundance in commercial PCB and PBDE mixtures, a number of organochlorine pesticides, as well as one natural product 2-(3{\textquoteright},5{\textquoteright}-dibromo-2{\textquoteright}-methoxyphenoxy)-3,5-dibromoanisole. The latter compound was isolated from a marine sponge and is similar in structure to a PBDE. All of the synthetic compounds were 14C-free except for the pesticide toxaphene. which had a modern 14C abundance, as did the brominated natural compound. The result for toxaphene was not surprising since it was commercially synthesized by the chlorination of camphene derived from pine trees. These results suggest that measuring the 14C content of halogenated organic compounds may be quite useful in establishing whether organic compounds encountered in the environment have natural or synthetic origins (or both) provided that any synthetic counterparts derive from petrochemical feedstock.},
	keywords = {Animals, Carbon Radioisotopes/*analysis, Environmental Pollutants/*analysis, Hydrocarbons, Halogenated/chemical synthesis/*chemistry, Insecticides/chemistry, Polychlorinated Biphenyls/chemistry, Porifera/*chemistry, Toxaphene/chemistry},
	isbn = {0269-7491 (Print)0269-7491 (Linking)
},
	url = {https://www.ncbi.nlm.nih.gov/pubmed/12395826},
	author = {Reddy, C. M. and Xu, L. and Eglinton, T. I. and Boon, J. P. and Faulkner, D. J.}
}
@article {2185,
	title = {The radiocarbon content of individual lignin-derived phenols: Technique and initial results},
	journal = {Radiocarbon},
	volume = {42},
	year = {2000},
	note = {365vkTimes Cited:19
Cited References Count:17
},
	month = {2000},
	pages = {219-227},
	abstract = {We present a method for the isolation of phenolic compounds derived from lignin for radiocarbon analysis. These phenols are generated by chemical oxidation of polymeric materials and derivatized for separation and recovery by preparative capillary gas chromatography (PCGC). This technique yields tens of micrograms of pure, stable compounds that can he converted to graphite and analyzed by accelerator mass spectrometry (AMS). Analysis of model flavor compounds and dated woods indicates that, in most cases, the radiocarbon (C-14) contents of the individual compounds, corrected for the contribution of the derivative, agree with that of the bulk material to within 20 parts per thousand.},
	keywords = {AMS, isotope-ratio, NOSAMS, oxidation-products},
	isbn = {0033-8222},
	author = {McNichol, A. P. and Ertel, J. R. and Eglinton, T. I.}
}
@article {825,
	title = {A reassessment of the sources and importance of land-derived organic matter in surface sediments from the Gulf of Mexico},
	journal = {Geochimica Et Cosmochimica Acta},
	volume = {62},
	year = {1998},
	note = {156xvTimes Cited:251Cited References Count:133},
	month = {Sep},
	pages = {3055-3075},
	abstract = {Organic matter in surface sediments from two onshore-offshore transects in the northwestern Gulf of Mexico was characterized by a variety of techniques, including elemental, stable carbon, radiocarbon, and molecular-level analyses. In spite of the importance of the Mississippi River as a sediment source, there is little evidence for a significant terrigenous input based on the low carbon:nitrogen ratios (8-5) and the enriched delta(13)C values of bulk sedimentary organic carbon (-19.7 parts per thousand to -21.7 parts per thousand). Radiocarbon analyses, on the other hand, yield depleted Delta(14)C values (-277 parts per thousand to -572 parts per thousand) which indicate that a significant fraction of the sedimentary organic carbon (OC) in all these surface sediments must be relatively old and most likely of allochthonous origin. CuO oxidations yield relatively low quantities of lignin products (0.4-1.4 mg/100 mg OC) along with compounds derived from proteins, polysaccharides, and lipids. Syringyl:vanillyl and cinnamyl:vanillyl ratios (averaging 1.6 and 0.5, respectively) and acid:aldehyde ratios for both vanillyl and syringyl phenols (averaging 0.8 and 1.2, respectively) indicate that the lignin present in sediments originates from nonwoody angiosperm sources and is highly degraded. The delta(13)C values of lignin phenols in shelf sediments are relatively depleted in (13)C (averaging -26.3 parts per thousand) but are increasingly enriched in (13)C at the slope sites (averaging -17.5 parts per thousand for the two deepest stations). We interpret these molecular and isotopic compositions to indicate that a significant fraction (greater than or equal to 50\%) of the lignin and, by inference, the land-derived organic carbon in northwestern Gulf of Mexico sediments ultimately originated from C(4) plants. The source of this material is likely to be soil organic matter eroded from the extensive grasslands of the Mississippi River drainage basin. Notably, the mixed C(4) and C(3) source and the highly degraded state of this material hampers its recognition and quantification in shelf and slope sediments. Our data are consistent with higher than previously estimated inputs of land-derived organic carbon to regions of the ocean, such as the Gulf of Mexico, with significant sources of terrigenous C(4)-derived organic matter. Copyright (C) 1998 Elsevier Science Ltd.},
	issn = {0016-7037},
	doi = {10.1016/S0016-7037(98)00217-8},
	author = {Go{\~n}i, M. A. and Ruttenberg, K. C. and Eglinton, T. I.}
}
