@article {white_refractory_2023,
	title = {Refractory Dissolved Organic Matter has Similar Chemical Characteristics but Different Radiocarbon Signatures With Depth in the Marine Water Column},
	journal = {Global Biogeochemical Cycles},
	volume = {37},
	number = {4},
	year = {2023},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2022GB007603},
	month = {04/2023},
	pages = {e2022GB007603},
	abstract = {The >5,000-year radiocarbon age (14C-age) of much of the 630 {\textpm} 30 Pg C oceanic dissolved organic carbon (DOC) reservoir remains an enigma in the marine carbon cycle. The fact that DOC is significantly older than dissolved inorganic carbon at every depth in the ocean forms the basis of our current framing of the marine DOC cycle, where some component persists over multiple cycles of ocean mixing. As a result, 14C-depleted, aged DOC is hypothesized to be present as a uniform reservoir with a constant 14C signature and concentration throughout the water column. However, key requirements of this model, including direct observations of DOC with similar 14C signatures in the surface and deep ocean, have never been met. Despite decades of research, the distribution of Δ14C values in marine DOC remains a mystery. Here, we applied a thermal fractionation method to compare operationally defined refractory DOC (RDOC) from different depths in the North Pacific Ocean. We found that RDOC shares chemical characteristics (as recorded by OC bond strength) throughout the water column but does not share the same 14C signature. Our results support one part of the current paradigm{\textemdash}that RDOC is comprised of structurally related components throughout the ocean that form a {\textquotedblleft}background{\textquotedblright} reservoir. However, in contrast to the current paradigm, our results are consistent with a vertical concentration gradient and a vertical and inter-ocean Δ14C gradient for RDOC. The observed Δ14C gradient is compatible with the potential addition of pre-aged DOC to the upper ocean.},
	keywords = {marine dissolved organic matter, radiocarbon, ramped pyrolysis oxidation},
	issn = {1944-9224},
	doi = {10.1029/2022GB007603},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2022GB007603},
	author = {White, Margot E. and Nguyen, Tran B. and Koester, Irina and Lardie Gaylord, Mary C. and Beman, J. Michael and Smith, Kenneth L. and McNichol, Ann P. and Beaupr{\'e}, Steven R. and Aluwihare, Lihini I.}
}
@article {197,
	title = {Rapid radiocarbon ((14)C) analysis of coral and carbonate samples using a continuous-flow accelerator mass spectrometry (CFAMS) system},
	journal = {Paleoceanography},
	volume = {26},
	year = {2011},
	note = {id: 1915; PT: J; UT: WOS:000296649300001},
	pages = {PA4212-PA4212},
	abstract = {Radiocarbon analyses of carbonate materials provide critical information for understanding the last glacial cycle, recent climate history and paleoceanography. Methods that reduce the time and cost of radiocarbon ((14)C) analysis are highly desirable for large sample sets and reconnaissance type studies. We have developed a method for rapid radiocarbon analysis of carbonates using a novel continuous-flow accelerator mass spectrometry (CFAMS) system. We analyzed a suite of deep-sea coral samples and compared the results with those obtained using a conventional AMS system. Measurement uncertainty is},
	issn = {0883-8305},
	doi = {10.1029/2011PA002174},
	author = {McIntyre, Cameron P. and Roberts, Mark L. and Burton, Joshua R. and McNichol, Ann P. and Burke, Andrea and Robinson, Laura F. and von Reden, Karl F. and W. J. Jenkins}
}
@article { ISI:000281306000013,
	title = {Radiocarbon Dating of Individual Lignin Phenols: A New Approach for Establishing Chronology of Late Quaternary Lake Sediments},
	journal = {ANALYTICAL CHEMISTRY},
	volume = {82},
	number = {{17}},
	year = {2010},
	month = {SEP 1},
	pages = {7119-7126},
	type = {Article},
	abstract = {The reliability of chronology is a prerequisite for meaningful paleoclimate reconstructions from sedimentary archives. The conventional approach of radiocarbon dating bulk organic carbon in lake sediments is often hampered by the old carbon effect, i.e., the assimilation of ancient dissolved inorganic carbon (DIC) derived from carbonate bedrocks or other sources. Therefore, radiocarbon dating is ideally performed on organic compounds derived from land plants that use atmospheric CO(2) and rapidly delivered to sediments. We demonstrate that lignin phenols isolated from lake sediments using reversed phase high performance liquid chromatography (HPLC) can serve as effective (14)C dating materials for establishing chronology during the late Quaternary. We developed a procedure to purify lignin phenols, building upon a published method. By isolating lignin from standard wood reference substances, we show that our method yields pure lignin phenols and consistent ages as the consensus ages and that our procedure does not introduce radiocarbon contamination. We further demonstrate that lignin phenol ages are compatible with varve counted and macrofossil dated sediment horizons in Steel Lake and Fayetteville Green Lake. Applying the new method to lake sediment cores from Lake Qinghai demonstrates that lignin phenol ages in Lake Qinghai are consistently younger than bulk total organic carbon (TOC) ages which are contaminated by old carbon effect. We also show that the age offset between lignin and bulk organic carbon differs at different Lake Qinghai sedimentary horizons, suggesting a variable hard water effect at different times and that a uniform age correction throughout the core is inappropriate.},
	issn = {0003-2700},
	doi = {10.1021/ac100494m},
	author = {Hou, Juzhi and Huang, Yongsong and Brodsky, Corynn and Alexandre, Marcelo R. and McNichol, Ann P. and King, John W. and Hu, Feng Sheng and Shen, Ji}
}
@article {506,
	title = {Reconnaissance dating A new radiocarbon method applied to assessing the temporal distribution of Southern Ocean deep-sea corals},
	journal = {Deep-Sea Research Part I-Oceanographic Research Papers},
	volume = {57},
	year = {2010},
	note = {id: 1924; PT: J; UT: WOS:000284750700012},
	pages = {1510-1520},
	abstract = {We have developed a rapid reconnaissance method of preparing graphite for (14)C/(12)C analysis Carbonate (similar to 15 mg) is combusted using an elemental analyzer and the resulting CO(2) is converted to graphite using a sealed tube zinc reduction method Over 85\% (n=45 replicates on twenty-one individual corals) of reconnaissance ages measured on corals ranging in age from 500 to 33 000 radiocarbon years (Ryr) are within two standard deviations of ages generated using standard hydrolysis methods on the same corals and all reconnaissance ages are within 300 Ryr of the standard hydrolysis ages Replicate measurements on three individual aragonitic corals yielded ages of 1076 +/- 35 Ryr (standard deviation n=5) 10 739 +/- 47 Ryr (n=8) and 40 146 +/- 3500 Ryr (n=9) No systematic biases were found using different cleaning methods or variable sample sizes Analysis of (13)C/(12)C was made concurrently with the (14)C/(12)C measurement to correct for natural fractionation and for fractionation during sample processing and analysis This technique provides a new rapid method for making accurate percent-level (14)C/(12)C analyses that may be used to establish the rates and chronology of earth system processes where survey-type modes of age estimation are desirable For example applications may include creation of sediment core-top maps preliminary age models for sediment cores and growth rate studies of marine organisms such as corals or mollusks We applied the reconnaissance method to more than 100 solitary deep-sea corals collected in the Drake Passage in the Southern Ocean to investigate their temporal and spatial distribution The corals used in this study are part of a larger sample set and the subset that was dated was chosen based on species as opposed to preservation state so as to exclude obvious temporal biases Similar to studies in other regions the distribution of deep-sea corals is not constant through time across the Drake Passage Most of the corals from the Burdwood Bank (continental shelf of Argentina) have ages ranging between 0 and 2500 calendar years whereas most of the corals from the Sars Seamount in the Drake Passage have ages between 10 000 and 12 500 calendar years Such differences may be caused in part by sampling biases but may also be caused by changes in larval transport nutrient supply or other environmental pressures (C) 2010 Elsevier Ltd All rights reserved},
	issn = {0967-0637},
	doi = {10.1016/j.dsr.2010.07.010},
	author = {Burke, Andrea and Robinson, Laura F. and McNichol, Ann P. and W. J. Jenkins and Scanlon, Kathryn M. and Gerlach, Dana S.}
}
@article { ISI:000268455600046,
	title = {Radiocarbon Analysis of Atmospheric Formaldehyde Using Cystamine Derivatization},
	journal = {ANALYTICAL CHEMISTRY},
	volume = {81},
	number = {{15}},
	year = {2009},
	month = {AUG 1},
	pages = {6310-6316},
	type = {Article},
	abstract = {A compound specific radiocarbon analysis method was developed to evaluate the C-14 composition of atmospheric formaldehyde. In this method, gaseous formaldehyde was collected with a high-volume air sampler using glass-fiber filters pretreated with sodium bisulfite. Collected formaldehyde was then released into water and derivatized with cysteamine to thiazolidine. The thiazolidine was extracted into dichloromethane and concentrated by evaporation. Concentrated thiazolidine was separated from other compounds using preparative capillary gas chromatography and uniquely collected as a phosphate salt with a fraction collector. The C-14 composition of the salt was analyzed by accelerator mass spectrometry after combustion to CO2 and subsequent reduction to graphite. In a pilot study, ambient formaldehyde samples collected on the roof of the CACS building at Narragansett Bay Campus, Narragansett, RI, showed a significantly larger fraction of fossil carbon than modern carbon.},
	issn = {0003-2700},
	doi = {10.1021/ac9004666},
	author = {Shen, Haiwei and McNichol, Ann P. and Xu, Li and Gagnon, Alan and Heikes, Brian G.}
}
@article {2141,
	title = {Radiocarbon Dating of Wood Samples and Plutonium Sediment Disturbance Studies at the Queen Anne{\textquoteright}s Revence Wreck Site},
	journal = {Southeastern Geology},
	volume = {40},
	year = {2001},
	note = {id: 1200},
	month = {2001},
	pages = {29-40},
	author = {Martens, Christopher S. and McNichol, Ann P.}
}
