@article {108,
	title = {14C and 13C characteristics of higher plant biomarkers in Washington margin surface sediments},
	journal = {Geochimica et Cosmochimica Acta},
	volume = {105},
	year = {2013},
	note = {id: 2267},
	pages = {14-30},
	abstract = {Plant wax lipids and lignin phenols are the two most common classes of molecular markers that are used to trace vascular plant-derived OM in the marine environment. However, their 13C and 14C compositions have not been directly compared, which can be used to constrain the flux and attenuation of terrestrial carbon in marine environment. In this study, we describe a revised method of isolating individual lignin phenols from complex sedimentary matrices for 14C analysis using high pressure liquid chromatography (HPLC) and compare this approach to a method utilizing preparative capillary gas chromatography (PCGC). We then examine in detail the 13C and 14C compositions of plant wax lipids and lignin phenols in sediments from the inner and mid shelf of the Washington margin that are influenced by discharge of the Columbia River. Plant wax lipids (including n-alkanes, n-alkanoic (fatty) acids, n-alkanols, and n-aldehydes) displayed significant variability in both δ13C (-28.3{\textperthousand} to -37.5{\textperthousand}) and Δ14C values (-204{\textperthousand} to +2{\textperthousand}), suggesting varied inputs and/or continental storage and transport histories. In contrast, lignin phenols exhibited similar δ13C values (between -30{\textperthousand} and -34{\textperthousand}) and a relatively narrow range of Δ14C values (-45{\textperthousand} to -150{\textperthousand}; HPLC-based measurement) that were similar to, or younger than, bulk OM (-195{\textperthousand} to -137{\textperthousand}). Moreover, lignin phenol 14C age correlated with the degradation characteristics of this terrestrial biopolymer in that vanillyl phenols were on average \~{}500 years older than syringyl and cinnamyl phenols that degrade faster in soils and sediments. The isotopic characteristics, abundance, and distribution of lignin phenols in sediments suggest that they serve as promising tracers of recently biosynthesized terrestrial OM during supply to, and dispersal within the marine environment. Lignin phenol 14C measurements may also provide useful constraints on the vascular plant end member in isotopic mixing models for carbon source apportionment, and for interpretation of sedimentary records of past vegetation dynamics.},
	issn = {0016-7037},
	doi = {10.1016/j.gca.2012.11.034},
	url = {http://www.sciencedirect.com/science/article/pii/S0016703712006874},
	author = {Feng, Xiaojuan and Benitez-Nelson, Bryan C. and Montlu{\c c}on, Daniel B. and Prahl, Fredrick G. and McNichol, Ann P. and Xu, Li and Repeta, Daniel J. and Eglinton, Timothy I.}
}
@article { ISI:000315194800002,
	title = {C-14 and C-13 characteristics of higher plant biomarkers in Washington margin surface sediments},
	journal = {GEOCHIMICA ET COSMOCHIMICA ACTA},
	volume = {105},
	year = {2013},
	month = {MAR 15},
	pages = {14-30},
	type = {Article},
	abstract = {Plant wax lipids and lignin phenols are the two most common classes of molecular markers that are used to trace vascular plant-derived OM in the marine environment. However, their C-13 and C-14 compositions have not been directly compared, which can be used to constrain the flux and attenuation of terrestrial carbon in marine environment. In this study, we describe a revised method of isolating individual lignin phenols from complex sedimentary matrices for C-14 analysis using high pressure liquid chromatography (HPLC) and compare this approach to a method utilizing preparative capillary gas chromatography (PCGC). We then examine in detail the C-13 and C-14 compositions of plant wax lipids and lignin phenols in sediments from the inner and mid shelf of the Washington margin that are influenced by discharge of the Columbia River. Plant wax lipids (including n-alkanes, n-alkanoic (fatty) acids, n-alkanols, and n-aldehydes) displayed significant variability in both delta C-13 (-28.3 parts per thousand to -37.5 parts per thousand) and Delta C-14 values (-204 parts per thousand to +2 parts per thousand), suggesting varied inputs and/or continental storage and transport histories. In contrast, lignin phenols exhibited similar delta C-13 values (between -30 parts per thousand and -34 parts per thousand) and a relatively narrow range of Delta C-14 values (-45 parts per thousand to -150 parts per thousand; HPLC-based measurement) that were similar to, or younger than, bulk OM (-195 parts per thousand to -137 parts per thousand). Moreover, lignin phenol C-14 age correlated with the degradation characteristics of this terrestrial biopolymer in that vanillyl phenols were on average similar to 500 years older than syringyl and cinnamyl phenols that degrade faster in soils and sediments. The isotopic characteristics, abundance, and distribution of lignin phenols in sediments suggest that they serve as promising tracers of recently biosynthesized terrestrial OM during supply to, and dispersal within the marine environment. Lignin phenol C-14 measurements may also provide useful constraints on the vascular plant end member in isotopic mixing models for carbon source apportionment, and for interpretation of sedimentary records of past vegetation dynamics. (C) 2012 Elsevier Ltd. All rights reserved.},
	issn = {0016-7037},
	doi = {10.1016/j.gca.2012.11.034},
	author = {Feng, Xiaojuan and Benitez-Nelson, Bryan C. and Montlu{\c c}on, Daniel B. and Prahl, Fredrick G. and McNichol, Ann P. and Xu, Li and Repeta, Daniel J. and Eglinton, Timothy I.}
}
