@article {2508,
	title = {Export of submicron particulate organic matter to mesopelagic depth in an oligotrophic gyre},
	journal = {Proceedings of the National Academy of Sciences},
	volume = {110},
	year = {2013},
	month = {Jun-07-2015},
	pages = {12565 - 12570},
	abstract = {Sixty percent of the world ocean by area is contained in oligotrophic gyres [Longhurst A (1995) Prog Oceanog 36:77-16], the biomass of which is dominated by picophytoplankton, including cyanobacteria and picoeukaryotic algae, as well as picoheterotrophs. Despite their recognized importance in carbon cycling in the surface ocean, the role of small cells and their detrital remains in the transfer of particulate organic matter (POM) to the deep ocean remains disputed. Because oligotrophic marine conditions are projected to expand under current climate trends, a better understanding of the role of small particles in the global carbon cycle is a timely goal. Here we use the lipid profiles, radiocarbon, and stable carbon isotopic signatures of lipids from the North Pacific Subtropical Gyre to show that in the surface ocean, lipids from submicron POM (here called extra-small POM) are distinct from larger classes of suspended POM. Remarkably, this distinct extra-small POM signature dominates the total lipids collected at mesopelagic depth, suggesting that the lipid component of mesopelagic POM primarily contains the exported remains of small particles. Transfer of submicron material to mesopelagic depths in this location is consistent with model results that claim the biological origin of exported carbon should be proportional to the distribution of cell types in the surface community, irrespective of cell size [Richardson TL, Jackson GA (2007) Science 315:838-840]. Our data suggest that the submicron component of exported POM is an important contributor to the global biological pump, especially in oligotrophic waters. 
},
	keywords = {Biogeochemistry, biomarkers, carbon isotopes, Oceanography},
	issn = {0027-8424},
	doi = {10.1073/pnas.1217514110},
	url = {http://www.pnas.org/cgi/doi/10.1073/pnas.1217514110https://syndication.highwire.org/content/doi/10.1073/pnas.1217514110},
	author = {Close, H. G. and Shah, S. R. and Ingalls, A. E. and Diefendorf, A. F. and Brodie, E. L. and Hansman, R. L. and Freeman, K. H. and Aluwihare, L. I. and Pearson, A.}
}
@article {638,
	title = {The power of radiocarbon in biogeochemical studies of the marine carbon cycle: insights from studies of dissolved and particulate organic carbon (DOC and POC)},
	journal = {Chem Rev},
	volume = {107},
	year = {2007},
	note = {McNichol, Ann PAluwihare, Lihini IengResearch Support, U.S. Gov{\textquoteright}t, Non-P.H.S.Review2007/02/16 09:00Chem Rev. 2007 Feb;107(2):443-66.},
	month = {Feb},
	pages = {443-66},
	issn = {0009-2665 (Linking)},
	doi = {10.1021/cr050374g},
	author = {McNichol, A. P. and Aluwihare, L. I.}
}
@article {1942,
	title = {Quantifying archaeal community autotrophy in the mesopelogic ocean using natural radiocarbon},
	journal = {Proc. Natl. Acad. Sci. USA},
	volume = {103},
	year = {2006},
	note = {id: 502},
	month = {2006},
	pages = {6442-6447},
	author = {Ingalls, A. E. and Shah, S. R. and Hansman, R. L. and Aluwihare, L. I. and Santos, G. M. and Druffel, E. R. M. and Pearson, A.}
}
@article {891,
	title = {Chemical composition and cycling of dissolved organic matter in the Mid-Atlantic Bight},
	journal = {Deep-Sea Research Part Ii-Topical Studies in Oceanography},
	volume = {49},
	year = {2002},
	note = {607kxTimes Cited:74Cited References Count:44},
	pages = {4421-4437},
	abstract = {This study focuses on the chemical characterization of high molecular-weight dissolved organic matter (HMW DOM) isolated from the Middle Atlantic Bight in April 1994 and March 1996. Using proton nuclear magnetic resonance spectroscopy ((HNMR)-H-1) and monosaccharide analysis we compared both spatial and temporal variations in the chemical structure of HMW DOM across this region. Our analyses support the presence of at least two compositionally distinct components to HMW DOM. The major component is acyl polysaccharide (APS), a biopolymer rich in carbohydrates, acetate and lipid, accounting for between 50\% and 80\% of the total high molecular-weight dissolved organic carbon (HMW DOC) in surface samples. APS is most abundant in fully marine, surface-water samples, and is a product of autochthonous production. Organic matter with spectral properties characteristic of humic substances is the second major component of HMW DOM. Humic substances are most abundant (up to 49\% of the total carbon) in samples collected from estuaries, near the coast, and in deep water, suggesting both marine and perhaps terrestrial sources. Radiocarbon analyses of neutral monosaccharides released by the hydrolysis of APS have similar and modern (average 71parts per thousand) Delta(14)C values. Radiocarbon data support our suggestion that these sugars occur as part of a common macromolecule, with an origin via recent biosynthesis. Preliminary radiocarbon data for total neutral monosaccharides isolated from APS at 300 and 750m show this fraction to be substantially enriched relative to total HMW DOC and DOC. The relatively enriched radiocarbon values of APS at depth suggest APS is rapidly transported into the deep ocean. (C) 2002 Elsevier Science Ltd. All rights reserved.},
	issn = {0967-0645},
	doi = {10.1016/S0967-0645(02)00124-8},
	author = {Aluwihare, L. I. and Repeta, D. J. and Chen, R. F.}
}
@article {639,
	title = {Gas chromatographic isolation of individual compounds from complex matrices for radiocarbon dating},
	journal = {Anal Chem},
	volume = {68},
	year = {1996},
	note = {Eglinton, T IAluwihare, L IBauer, J EDruffel, E RMcNichol, A Peng1996/03/01 00:00Anal Chem. 1996 Mar 1;68(5):904-12. doi: 10.1021/ac9508513.},
	month = {Mar 01},
	pages = {904-12},
	abstract = {This paper describes the application of a novel, practical approach for isolation of individual compounds from complex organic matrices for natural abundance radiocarbon measurement. This is achieved through the use of automated preparative capillary gas chromatography (PCGC) to separate and recover sufficient quantities of individual target compounds for (14)C analysis by accelerator mass spectrometry (AMS). We developed and tested this approach using a suite of samples (plant lipids, petroleums) whose ages spanned the (14)C time scale and which contained a variety of compound types (fatty acids, sterols, hydrocarbons). Comparison of individual compound and bulk radiocarbon signatures for the isotopically homogeneous samples studied revealed that Delta(14)C values generally agreed well (+/-10\%). Background contamination was assessed at each stage of the isolation procedure, and incomplete solvent removal prior to combustion was the only significant source of additional carbon. Isotope fractionation was addressed through compound-specific stable carbon isotopic analyses. Fractionation of isotopes during isolation of individual compounds was minimal (<5 per thousand for delta(13)C), provided the entire peak was collected during PCGC. Trapping of partially coeluting peaks did cause errors, and these results highlight the importance of conducting stable carbon isotopic measurements of each trapped compound in concert with AMS for reliable radiocarbon measurements. The addition of carbon accompanying derivatization of functionalized compounds (e.g., fatty acids and sterols) prior to chromatographic separation represents a further source of potential error. This contribution can be removed using a simple isotopic mass balance approach. Based on these preliminary results, the PCGC-based approach holds promise for accurately determining (14)C ages on compounds specific to a given source within complex, heterogeneous samples.},
	issn = {0003-2700 (Linking)},
	doi = {10.1021/ac9508513},
	author = {Eglinton, T. I. and Aluwihare, L. I. and Bauer, J. E. and Druffel, E. R. and McNichol, A. P.}
}
@article {2338,
	title = {Preparative capillary gas chromatographic isolation of individual compounds from complex matrices for radiocarbon dating},
	journal = {Analytical Chemistry},
	volume = {68},
	year = {1996},
	note = {id: 1340},
	month = {1996},
	pages = {904-912},
	author = {Eglinton, T. I. and Aluwihare, L. I. and Bauer, J. E. and Druffel, E. R. M. and McNichol, A. P.}
}
