@article {2333,
	title = {Automated systems and techniques utilized at the NOSAMS sample preparation laboratory: An update of productivity and quality issues},
	journal = {Radiocarbon},
	volume = {38},
	year = {1996},
	note = {id: 959},
	month = {1996},
	pages = {38-39},
	author = {Gagnon, A. R. and McNichol, A. P. and Hutton, D. L. and Osborne, E. A. and Donoghue, J. C.}
}
@article {2348,
	title = {Improvements in procedural blanks at NOSAMS: Reflections of improvements in sample preparation and accelerator operation},
	journal = {Radiocarbon},
	volume = {37},
	year = {1995},
	note = {Ud868Times Cited:16
Cited References Count:6
},
	month = {1995},
	pages = {683-691},
	abstract = {During the four years the Sample Preparation Laboratory (SPL) at the National Ocean Sciences Accelerator Mass Spectrometer (NOSAMS) Facilty has been in operation we have accumulated much data from which we can assess our progress. We evaluate our procedural blanks here and describe modifications in our procedures that have improved our analyses of older samples. In the SPL, we convert three distinct types of samples-seawater, CaCO3 and organic carbon-to CO2 prior to preparing graphite for the accelerator and have distinct procedural blanks for each procedure. Dissolved inorganic carbon (Sigma CO2) is extracted from acidified seawater samples by sparging with a nitrogen carrier gas. We routinely analyze {\textquoteright}{\textquoteright}line blanks{\textquoteright}{\textquoteright} by processing CO2 from a C-14-dead source through the entire stripping procedure. Our hydrolysis blank, IAEA C-1, is prepared by acidifying in vacuo with 100\% H3PO4 at 60 degrees C overnight, identical to our sample preparation. We use a dead graphite, NBS-21, or a commercially available carbon powder for our organic combustion blank; organic samples are combusted at 850 degrees C for 5 h using CuO to provide the oxidant. Analysis of our water stripping data suggests that one step in the procedure contributes the major portion of the line blank. At present, the contribution from the line blank has no effect on our seawater analyses (fraction modern (fm) between 0.7 and 1.2). Our hydrolysis blanks can have an fm value as low as 0.0006, but are more routinely between 0.0020 and 0.0025. The fm of our best organic combustion blanks is higher than those routinely achieved in other laboratories and we are currently altering our methods to reduce it.},
	keywords = {SPECTROMETRY},
	isbn = {0033-8222},
	author = {McNichol, A. P. and Gagnon, A. R. and Osborne, E. A. and Hutton, D. L. and vonReden, K. F. and Schneider, R. J.}
}
@article {848,
	title = {Automated Sample Processing at the National Ocean Sciences Ams Facility},
	journal = {Nuclear Instruments \& Methods in Physics Research Section B-Beam Interactions with Materials and Atoms},
	volume = {92},
	year = {1994},
	note = {Nv547Times Cited:9Cited References Count:1},
	month = {Jun},
	pages = {129-133},
	abstract = {The high throughput and high precision requirements for the NOSAMS facility have made it essential to automate many of the stages in sample processing. These automated procedures increase the sample capacity for the lab while reducing errors in sample preparation. Automation has also allowed sample histories to be recorded and saved in Sybase, a relational data base.},
	issn = {0168-583x},
	doi = {10.1016/0168-583x(94)95991-9},
	author = {Cohen, G. J. and Hutton, D. L. and Osborne, E. A. and vonReden, K. F. and Gagnon, A. R. and McNichol, A. P. and Jones, G. A.}
}
@article {847,
	title = {Internal and External Checks in the Nosams Sample Preparation Laboratory for Target Quality and Homogeneity},
	journal = {Nuclear Instruments \& Methods in Physics Research Section B-Beam Interactions with Materials and Atoms},
	volume = {92},
	year = {1994},
	note = {Nv547Times Cited:14Cited References Count:5},
	month = {Jun},
	pages = {158-161},
	abstract = {In the NOSAMS sample preparation laboratory (SPL) we have developed rigorous internal procedures aimed at ensuring that sample preparation introduces as little error into our analyses as possible and identifying problems rapidly. Our three major CO2 preparation procedures are: stripping inorganic carbon from seawater, hydrolyzing CaCO3, and oxidizing organic matter. For seawater, approximately 10\% of our analyses are standards or blanks which we use to demonstrate extraction of virtually all the inorganic carbon. Analysis of the stable carbon isotopic composition of the CO2 extracted from our standards indicates a precision of better than 0.15-0.20 parts per thousand. We also routinely process C-14-free CO2 in our stripping lines to demonstrate the absence of a significant process-dependent blank. For organic combustions and CaCO3 hydrolyses, we use the carbon yield (\% organic carbon (OC) or \% CaCO3 by weight) as a check on our sample procedures. We have analyzed the blank contribution of these procedures as a function of sample size. Our organic carbon blank is constant at approximately 0.4\% modem for samples containing greater than 1 mg C and our carbonate blank is less than 0.2\% modern for samples containing more than 0.5 mg C. We use a standard Fe/H-2 catalytic reduction to prepare graphite from CO2. We check the completeness of our reactions with the pressure data stored during the reaction as well as use a robot to determine a gravimetric yield. All graphite undergoes a visual inspection and is rejected if any heterogeneities are present. We have recombusted graphite made from CO2 with deltaC-13 values ranging from -42 to 1 parts per thousand and determined that the deltaC-13 of the recombusted carbon agrees with that from the pure gas to within 0.05 parts per thousand, demonstrating little or no fractionation during the treatment of the sample. The deltaC-13 we measure on the CO2 generated from more than 75\% of our samples is compared to the deltaC-13 measured on the AMS as a further check of our procedures. As further external checks, we analyzed the International Atomic Energy Association (IAEA) samples during the establishment of our laboratory and are presently participating in the third international radiocarbon intercalibration (TIRI) exercise.},
	issn = {0168-583x},
	doi = {10.1016/0168-583x(94)95997-8},
	author = {Osborne, E. A. and McNichol, A. P. and Gagnon, A. R. and Hutton, D. L. and Jones, G. A.}
}
@article {846,
	title = {Tic, Toc, Dic, Doc, Pic, Poc - Unique Aspects in the Preparation of Oceanographic Samples for C-14 Ams},
	journal = {Nuclear Instruments \& Methods in Physics Research Section B-Beam Interactions with Materials and Atoms},
	volume = {92},
	year = {1994},
	note = {Nv547Times Cited:82Cited References Count:9},
	month = {Jun},
	pages = {162-165},
	abstract = {The radiocarbon content of discrete carbon pools (total (T), dissolved (D), and particulate (P) inorganic (I) and organic (O) carbon (C)) is a useful tracer of carbon cycling within the modem and past ocean. The isolation of different carbon pools in the ocean environment and conversion to CO2 presents unique analytical problems for the radiocarbon chemist. In general, isolation and preparation of inorganic carbon presents few problems; dissolved carbon is easily extracted by acidifying the sample and stripping with an inert gas. Carbon is also readily isolated from particulate carbonate samples; in this case, CO2 is prepared by hydrolysis of the substrate with phosphoric acid. The isolation and preparation of organic carbon presents a much greater problem. Dissolved organic carbon (DOC) must first be isolated from DIC and then oxidized in the presence of very high salt concentrations. We present results from a closed-tube combustion method in which the DIC-free seawater is evaporated to dryness, transferred to a clean combustion tube, and oxidized overnight at 550-degrees-C. Combustion of total organic carbon (TOC) in sediments with a high inorganic carbon content is also difficult. Removal of CaCO3 with acid leaves severely deliquescent salts which, if not thoroughly dried, cause combustion tubes to explode. Removal of the salts by rinsing can also remove significant amounts of organic matter. Finally, we present results from a local coastal region.},
	issn = {0168-583x},
	doi = {10.1016/0168-583x(94)95998-6},
	author = {McNichol, A. P. and Osborne, E. A. and Gagnon, A. R. and Fry, B. and Jones, G. A.}
}
@conference {1655,
	title = {Internal and external checks in the NOSAMS Sample Preparation Laboratory for target quality and homogeneity},
	booktitle = {6th International Conference on Accelerator Mass Spectrometry},
	year = {1993},
	note = {id: 958},
	month = {1993},
	pages = {75},
	address = {Canberra, Australia},
	author = {McNichol, A. P. and Gagnon, A. R. and Osborne, E. A. and Hutton, D. L. and Jones, G. A.}
}
@conference {1662,
	title = {Laboratory automation at the National Ocean Sciences AMS Facility},
	booktitle = {6th Internation Conference on Accelerator Mass Spectrometry},
	year = {1993},
	note = {id: 927},
	month = {1993},
	pages = {74},
	address = {Canberra, Australia},
	author = {Cohen, G. J. and Hutton, D. L. and von Reden, K. F. and Osborne, E. A. and McNichol, A. P. and Jones, G. A.}
}
@conference {1700,
	title = {The National Ocean Sciences AMS Facility at Woods Hole Oceanographic Institution},
	booktitle = {6th International Conference on Accelerator Mass Spectrometry},
	year = {1993},
	note = {id: 930},
	month = {1993},
	pages = {46},
	address = {Canberra, Australia},
	author = {Jones, G. A. and Schneider, R. J. and von Reden, K. F. and McNichol, A. P. and Gagnon, A. R. and Cohen, G. J. and Osborne, E. A. and Hutton, D. L. and Kessel, E. D. and Elder, K. L.}
}
@article {2401,
	title = {Illumination of a Black-Box - Analysis of Gas-Composition during Graphite Target Preparation},
	journal = {Radiocarbon},
	volume = {34},
	year = {1992},
	note = {Kf389Times Cited:63
Cited References Count:10
},
	month = {1992},
	pages = {321-329},
	abstract = {We conducted a study of relative gas composition changes of CO2, CO and CH4 during the formation of graphite targets using different temperatures, catalysts and methods. Reduction with H-2 increases the reaction rate without compromising the quality of the AMS target produced. Methane is produced at virtually any temperature, and the amount produced is greater at very low temperatures. The reduction of CO to graphite is very slow when H-2 is not included in the reaction.},
	keywords = {deposition},
	isbn = {0033-8222},
	author = {McNichol, A. P. and Gagnon, A. R. and Jones, G. A. and Osborne, E. A.}
}
@article {2407,
	title = {Illumination of a black box: Gas composition changes during graphite target preparation for AMS (Proceedings of the 14th International Radiocarbon Conference, 1991)},
	journal = {Radiocarbon},
	volume = {34},
	year = {1991},
	note = {id: 1745},
	month = {1991},
	pages = {321-329},
	author = {McNichol, A. P. and Gagnon, A. R. and Jones, G. A. and Osborne, E. A.}
}
