@article {hanke_sequential_2023,
	title = {Sequential thermal analysis of complex organic mixtures: Procedural standards and improved CO2 purification capacity},
	journal = {Radiocarbon},
	volume = {65},
	number = {2},
	year = {2023},
	note = {Publisher: Cambridge University Press},
	month = {03/2023},
	pages = {389{\textendash}409},
	abstract = {Sequential thermal analysis allows for deconvoluting the refractory nature and complexity of carbon mixtures embedded in mineral matrices for subsequent offline stable carbon and radiocarbon (14C) isotope analyses. Originally developed to separate Holocene from more ancient sedimentary organic matter to improve dating of marine sediments, the Ramped Pyrolysis and Oxidation (RPO) apparatus, or informally, the {\textquotedblleft}dirt burner{\textquotedblright} is now used to address pressing questions in the broad field of biogeochemistry. The growing interest in the community now necessitates improved handling and procedures for routine analyses of difficult sample types. Here we report on advances in CO2 purification during sample processing, modifications to the instrumentation at the National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) facility, and introduce sodium bicarbonate procedural standards with differing natural abundance 14C signatures for blank assessment. Measurements from different environmental samples are used to compare the procedure to the different generations of sequential thermal analyses. With this study, we aim to improve the standardization of the procedures and prepare this instrumentation for innovations in online stable carbon isotopes and direct AMS-interface measurements in the future.},
	keywords = {chemical analysis, dirt burner, full oxidation (FOX) mode, Radiocarbon dating, ramped pyrolysis oxidation},
	issn = {0033-8222, 1945-5755},
	doi = {10.1017/RDC.2023.13},
	url = {https://www.cambridge.org/core/journals/radiocarbon/article/sequential-thermal-analysis-of-complex-organic-mixtures-procedural-standards-and-improved-co2-purification-capacity/E225F01B421614EE176553014E7B38BE},
	author = {Hanke, Ulrich M. and Gagnon, Alan R. and Reddy, Christopher M. and Gaylord, Mary C. Lardie and Cruz, Anne J. and Galy, Valier and Hansman, Roberta L. and Kurz, Mark D.}
}
@article {15,
	title = {Ultra-Small Graphitization Reactors for Ultra-Microscale C-14 Analysis at the National Ocean Sciences Accelerator Mass Spectrometry (Nosams) Facility},
	journal = {Radiocarbon},
	volume = {57},
	year = {2015},
	note = {PT: J; TC: 1; UT: WOS:000351052600009},
	pages = {109-122},
	abstract = {In response to the increasing demand for C-14 analysis of samples containing less than 25 mu g C, ultra-small graphitization reactors with an internal volume of similar to 0.8 mL were developed at NOSAMS. For samples containing 6 to 25 mu g C, these reactors convert CO2 to graphitic carbon in approximately 30 min. Although we continue to refine reaction conditions to improve yield, the reactors produce graphite targets that are successfully measured by AMS. Graphite targets produced with the ultra-small reactors are measured by using the Cs sputter source on the CFAMS instrument at NOSAMS where beam current was proportional to sample mass. We investigated the contribution of blank carbon from the ultra-small reactors and estimate it to be 0.3 +/- 0.1 mu g C with an Fm value of 0.43 +/- 0.3. We also describe equations for blank correction and propagation of error associated with this correction. With a few exceptions for samples in the range of 6 to 7 mu g C, we show that corrected Fm values agree with expected Fm values within uncertainty for samples containing 6-100 mu g C.},
	issn = {0033-8222},
	doi = {10.2458/azu_rc.57.18118},
	author = {Walter, Sunita R. Shah and Gagnon, Alan R. and Roberts, Mark L. and McNichol, Ann P. and Gaylord, Mary C. Lardie and Klein, Elizabeth}
}
@conference {1564,
	title = {The Antarctic Radiocarbon Storage Ring},
	booktitle = {8th International Conference on Accelerator Mass Spectrometry},
	year = {1999},
	note = {id: 1791},
	month = {1999},
	address = {Vienna, Austria},
	author = {Schneider, Robert J. and McNichol, Ann P. and von Reden, Karl F. and Elder, Kathryn L. and Gagnon, Alan R. and Key, Robert M. and Quay, Paul D.}
}
