@article {1093,
	title = {Assessing the Blank Carbon Contribution, Isotope Mass Balance, and Kinetic Isotope Fractionation of the Ramped Pyrolysis/Oxidation Instrument at NOSAMS},
	journal = {Radiocarbon},
	volume = {59223{\textendash}22493970409},
	year = {2017},
	month = {Jan-02-2017},
	pages = {179 - 193},
	abstract = {We estimate the blank carbon mass over the course of a typical Ramped PyrOx (RPO) analysis (150-1000 degrees C; 5 degrees C x min(-1)) to be (3.7 +/- 0.6) mu g C with an Fm value of 0.555 +/- 0.042 and a delta C-13 value of (-29.0 +/- 0.1)parts per thousand VPDB. Additionally, we provide equations for RPO Fm and delta C-13 blank corrections, including associated error propagation. By comparing RPO mass-weighted mean and independently measured bulk delta C-13 values for a compilation of environmental samples and standard reference materials (SRMs), we observe a small yet consistent delta C-13 depletion within the RPO instrument (mean-bulk: mu = -0.8 parts per thousand; +/- 1 sigma = 0.9 parts per thousand; n = 66). In contrast, because they are fractionation-corrected by definition, mass-weighted mean Fm values accurately match bulk measurements (mean-bulk: mu = 0.005; +/- 1 sigma = 0.014; n = 36). Lastly, we show there exists no significant intra-sample delta C-13 variability across carbonate SRM peaks, indicating minimal mass-dependent kinetic isotope fractionation during RPO analysis. These data are best explained by a difference in activation energy between C-13- and C-12-containing compounds ((13-12)Delta E) of 0.3-1.8 J x mol(-1), indicating that blank and mass-balance corrected RPO delta C-13 values accurately retain carbon source isotope signals to within 1-2 parts per thousand.},
	keywords = {Ramped PyrOx; blank assessment; kinetic fractionation},
	issn = {0033-8222},
	doi = {10.1017/RDC.2017.3},
	url = {https://www.cambridge.org/core/product/identifier/S0033822217000030/type/journal_article},
	author = {Hemingway, Jordon D and Galy, Valier V and Gagnon, Alan R and Grant, Katherine E and Rosengard, Sarah Z and Soulet, Guillaume and Zigah, Prosper K and McNichol, Ann P}
}
