TY - JOUR
T1 - Sources and distribution of CuO-derived benzene carboxylic acids in soils and sediments
AU - Dickens, Angela F.
AU - Gudeman, Jack A.
AU - Gélinas, Yves
AU - Baldock, Jeffrey A.
AU - Tinner, Willy
AU - Hu, Feng Sheng
AU - Hedges, John I.
N1 - Funding Information:
We are grateful to M. Goñi, F. Prahl, R. Keil and the UW Marine Organic Geochemistry (MOG) and Eglinton lab reading groups for comments on earlier drafts of the paper. K. Prentice obtained and prepared the alder wood and M. Foy and E. Lessard helped grow the phytoplankton cultures. We thank J. Richey and A. Krusche for sharing the Ji-Paraná FSS sample and J. Skjemstad for providing the soil and Australian grass charcoal samples. The SC soil charcoal sample was collected during a field trip with C. Masiello and J. Harden. D. Wilbur performed supplemental elemental analyses and C. Preston directed A.F.D. to a number of useful classic humic papers. The manuscript benefited from thoughtful reviews by P. Louchouarn and an anonymous reviewer. The research was funded jointly by CSIRO, US NSF, and NASA-LBA Ecology grants and by a NSF Graduate Research Fellowship to A.F.D. This is CAMREX publication number 136.
PY - 2007/8
Y1 - 2007/8
N2 - Cupric oxide (CuO) oxidation is a powerful tool for tracing different forms of organic carbon (OC), particularly vascular plant-derived OC, through the environment. The method produces a suite of benzene carboxylic acids (BCAs) whose sources have been unclear, but some of which have been used as tracers of soil OC in the ocean. In particular, some evidence suggested they might derive from charcoal, making them a potentially powerful tracer of combustion-derived OC within the environment. In order to constrain their sources and distributions in the environment, we analyzed the concentrations of an extended suite of 18 BCAs from over 75 samples. The entire suite of compounds was produced from most pure organic samples, as well as from charcoal, indicating that a variety of processes lead to their production. Both terrestrial and marine geochemical samples yielded the suite, and OC content, not charcoal, appears to control the total BCA yield. The compounds cannot, therefore, be used as specific tracers of charcoal in soils and sediments. Types of OC produced by marine biota (i.e. glucose, protein and degraded phytoplankton) produce many of the BCAs, but not 3,5-dihydroxybenzoic acid, suggesting that previous applications of this compound for tracing soil OC in the ocean may be robust. Additionally, we present a new ratio based on the entire BCA suite, which may provide a further constraint on the amount of soil OC present in ocean sediments.
AB - Cupric oxide (CuO) oxidation is a powerful tool for tracing different forms of organic carbon (OC), particularly vascular plant-derived OC, through the environment. The method produces a suite of benzene carboxylic acids (BCAs) whose sources have been unclear, but some of which have been used as tracers of soil OC in the ocean. In particular, some evidence suggested they might derive from charcoal, making them a potentially powerful tracer of combustion-derived OC within the environment. In order to constrain their sources and distributions in the environment, we analyzed the concentrations of an extended suite of 18 BCAs from over 75 samples. The entire suite of compounds was produced from most pure organic samples, as well as from charcoal, indicating that a variety of processes lead to their production. Both terrestrial and marine geochemical samples yielded the suite, and OC content, not charcoal, appears to control the total BCA yield. The compounds cannot, therefore, be used as specific tracers of charcoal in soils and sediments. Types of OC produced by marine biota (i.e. glucose, protein and degraded phytoplankton) produce many of the BCAs, but not 3,5-dihydroxybenzoic acid, suggesting that previous applications of this compound for tracing soil OC in the ocean may be robust. Additionally, we present a new ratio based on the entire BCA suite, which may provide a further constraint on the amount of soil OC present in ocean sediments.
UR - http://www.scopus.com/inward/record.url?scp=34547135199&partnerID=8YFLogxK
U2 - 10.1016/j.orggeochem.2007.04.004
DO - 10.1016/j.orggeochem.2007.04.004
M3 - Article
AN - SCOPUS:34547135199
SN - 0146-6380
VL - 38
SP - 1256
EP - 1276
JO - Organic Geochemistry
JF - Organic Geochemistry
IS - 8
ER -