Characterizing halogenated organic compounds in the terrestrial-aquatic continuum
EMSL Project ID
49222
Abstract
Halogenated organic compound(s) (HOCs) play prominent roles in atmospheric ozone chemistry, as environmental and human health contaminants (i.e. persistent organic pollutants), and have potential pharmaceutical applications. Until recently, HOCs are believed to be primarily anthropogenic. Emerging evidence, however, indicates that organically bounded halogens are ubiquitous in soil and marine environments [Leri and Myneni, 2012; Leri et al., 2014; Myneni, 2002]. Studies on marine sinking particles and sediments elucidated that HOCs may be stable enough to resist degradation in the water column and be preserved in sediments [Leri et al., 2010]. A recent study suggested that brominated and iodinated organic compounds, formed via sunlight induced halogenation, can account for ~100 gigagrams of carbon in the terrestrial-aquatic continuum (TAC) [Méndez-Díaz et al., 2014]. In addition, iron facilitated and enzyme mediated halogenation likely generate even more HOCs than sunlight. Thus, we postulate that naturally produced HOCs constitute a globally significant fraction of very actively cycled organic carbon. Since most of the known anthropogenic HOCs are persistent in the environment, we hypothesize that the naturally derived HOCs will behave similarly. These proposed concepts, therefore, have significant implications to carbon cycling and sequestration. Halogens are abundant elements on Earth and their fluxes in organic and inorganic forms occur across multiple interfaces occur in the Earth system (Box 1). It is, therefore, critical to understand halogens’ biogeochemical cycles and their roles in the global carbon cycle. Despite numerous evidence pointing to the ubiquity of organically bounded halogens, their chemical characteristics and structures remain predominately unknown. Characterization of naturally derived HOC’s will require application of new analytical tools. EMSL has the advanced instrumentation to characterize HOCs and thereby provide a means to investigate the importance of HOC’s to a variety of environmental problems and biogeochemical pathways, and hence, improving our understanding of carbon cycling across the TAC [Bauer et al., 2013; Regnier et al., 2013].
Project Details
Start Date
2016-02-04
End Date
2016-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members
Related Publications
Leonce, B.C., O.R. Harvey, Y. Liu, L-.J. Kuo (2016), Energy-dependent and Fraction Specific Response of Pyrogenic Dissolved Organic Carbon during Photodegradation, AGU Fall Meeting 2016, San Francisco, CA.
Liu, Y., T.S. Bianchi, N.D. Ward, A.R. Arellano, A. Rivas-Ubach, N. Tolic, L. Pasa-Tolic, and L-.J. Kuo (2016), Molecular Signature of Organic Carbon Along a Salinity Gradient in Suwannee River Plume, Oral Presentation, AGU Fall Meeting 2016, San Francisco, CA.
Tolić, N., Y. Liu, A. Liyu, Y. Shen, M. M. Tfaily, E. B.Kujawinski, K. Longnecker, L-J Kuo, E. W.Robinson, L. Pa?a-Tolić, N. J. Hess (2017) Formularity: Software for Automated Formula Assignment of Natural and Other Organic Matter from Ultra-High Resolution Mass Spectra. Analytical Chemistry 89, 12659-12665.
Tolic N., Y. Liu, A.V. Liyu, Y. Shen, M.M. Tfaily, E.B. Kujawinski, and K. Longnecker, et al. 2017. "Formularity: Software for Automated Formula Assignment of Natural and Other Organic Matter from Ultra-High Resolution Mass Spectra." Analytical Chemistry 89, no. 23:12659-12665. PNNL-SA-128094. doi:10.1021/acs.analchem.7b03318