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Rudolf Jaffé

Bio: Rudolf Jaffé is an academic researcher from Florida International University. The author has contributed to research in topics: Dissolved organic carbon & Organic matter. The author has an hindex of 58, co-authored 182 publications receiving 10268 citations. Previous affiliations of Rudolf Jaffé include Hokkaido University & Indiana University.


Papers
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Journal ArticleDOI
TL;DR: The results demonstrate that the combination of fluorescence quenching titrations with EEM-PARAFAC was reproducible and sensitive to determine the binding properties of humic-like components with trace metals.
Abstract: Natural dissolved organic matter (DOM) is composed of a variety of organic compounds, which can interact with metals in aquatic environments. The interactions between DOM and two metals of environmental concern (Cu(II) and Hg(II)) were studied using fluorescence quenching titrations combined with excitation-emission matrix (EEM) spectra and parallel factor analysis (PARAFAC). This allowed characterizing the specific interactions between eight fluorescent components in DOM and two metals. Triplicate titration experiments showed good reproducibility when assessing the interactions between humic-like components with Cu(ll). Our data show clear differences in metal-DOM interaction for samples of different DOM composition and between two different metals. The results demonstrate that the combination of fluorescence quenching titrations with EEM-PARAFAC was reproducible and sensitive to determine the binding properties of humic-like components with trace metals. The enhancement in fluorescence intensity after its initial decrease for the protein-like components with addition of Cu(II) was observed at mangrove-dominated sites, suggesting changes in the molecular environments of protein-like components due to increased Cu(II) interaction. The application of EEM-PARAFAC in fluorescence quenching studies is a useful tool to evaluate intermolecular DOM and DOM-trace metals interactions.

492 citations

Journal ArticleDOI
TL;DR: This article used absorbance and fluorescence spectroscopy with parallel factor analysis (PARAFAC) to characterize dissolved organic matter (DOM) in 43 streams distributed throughout watersheds of mixed land use in southern Ontario, Canada.
Abstract: Surface water samples were collected from 43 streams distributed throughout watersheds of mixed land use in southern Ontario, Canada. Absorbance and fluorescence spectroscopy with parallel factor analysis (PARAFAC) was used to characterize dissolved organic matter (DOM). DOM characteristics were related to environmental variables, microbial activity indicators (bacterial production and extracellular leucine aminopeptidase activity), and riparian land use to understand better how these factors influence DOM in streams. PARAFAC produced a six-component model (C1 to C6). Temperature correlated with each PARAFAC component, suggesting that water source, drainage area, and light penetration broadly affected DOM characteristics. C1 and C2 represented terrestrial, humic-like DOM fluorophore groups and comprised 41–65% of stream DOM fluorescence. C5, a tryptophan-like component, related negatively to a humification index but positively to leucine-aminopeptidase activity and recently produced DOM, suggesting that C5 consisted of autochthonous, microbially produced DOM. C3, C4, and C6 showed signs of quinone-like, humic-like, and microbial transformable fluorophores. The distribution of these potentially redox-active PARAFAC components indicated that DOM was in a more reduced state in streams with higher bacterial production and agricultural land use than in streams with increased wetlands area, which had greater relative abundance of the oxidized quinone-like component. Anthropogenic land use and microbial activity altered the quantity and quality of DOM exported from human-affected streams from that observed in forest- and wetland-dominated streams. DOM in agriculturally affected streams was likely more labile and accessible to the microbial community than DOM in wetland streams, which supported low rates of microbial activity.

487 citations

Journal ArticleDOI
TL;DR: In this article, the distributions of fluorescent components in dissolved organic matter (DOM) from Ise Bay, Japan, were determined by excitation emission matrix (EEM) fluorescence spectroscopy combined with parallel factor analysis (PARAFAC).
Abstract: The distributions of fluorescent components in dissolved organic matter (DOM) from Ise Bay, Japan, were determined by excitation emission matrix (EEM) fluorescence spectroscopy combined with parallel factor analysis (PARAFAC). Three terrestrial humic-like, one marine humic-like, and three non-humic-like fluorescent components were identified by PARAFAC, and the environmental dynamics of individual fluorescent components in the bay area were evaluated. The observed linear relationships between salinity and abundance of two of the three humic-like components in the bay area indicate a terrestrial origin and conservative mixing behavior of these components. On the other hand, nonconservative mixing for the other terrestrial and the marine humic-like components was observed, indicating that the sources of these were other than solely riverine inputs. Thus, in addition to riverine sources, this terrestrial humic-like component may receive inputs from biogeochemical reworking of terrestrial DOM and/or particulate organic matter, while the most likely sources for the marine humic-like component are estuarine biological activity and/or microbial reworking of plankton-derived DOM. From the spatial distributions in the bay area as well as their relationships with salinity, two of the non-humic-like components were suggested to be of autochthonous estuarine origin and likely represent biologically labile components. Microbial degradation processes were suggested to be important factors driving the dynamics of another non-humic-like component. This study exemplifies the potential applicability of EEM-PARAFAC in studies of fluorescent DOM dynamics in estuaries.

453 citations

Journal ArticleDOI
TL;DR: In this paper, the variability in the quality of 134 DOM samples collected from 12 Long Term Ecological Research stations by quantification of organic carbon and nitrogen concentration in addition to analysis of UV-visible absorbance and fluorescence spectra were further characterized by parallel factor analysis.
Abstract: [1] Source, transformation, and preservation mechanisms of dissolved organic matter (DOM) remain elemental questions in contemporary marine and aquatic sciences and represent a missing link in models of global elemental cycles. Although the chemical character of DOM is central to its fate in the global carbon cycle, DOM characterizations in long-term ecological research programs are rarely performed. We analyzed the variability in the quality of 134 DOM samples collected from 12 Long Term Ecological Research stations by quantification of organic carbon and nitrogen concentration in addition to analysis of UV-visible absorbance and fluorescence spectra. The fluorescence spectra were further characterized by parallel factor analysis. There was a large range in both concentration and quality of the DOM, with the dissolved organic carbon (DOC) concentration ranging from less than 1 mgC/L to over 30 mgC/L. The ranges of specific UV absorbance and fluorescence parameters suggested significant variations in DOM composition within a specific study area, on both spatial and temporal scales. There was no correlation between DOC concentration and any DOM quality parameter, illustrating that comparing across biomes, large variations in DOM quality are not necessarily associated with corresponding large ranges in DOC concentrations. The data presented here emphasize that optical properties of DOM can be highly variable and controlled by different physical (e.g., hydrology), chemical (e.g., photoreactivity/redox conditions), and biological (e.g., primary productivity) processes, and as such can have important ecological consequences. This study demonstrates that relatively simple DOM absorbance and/or fluorescence measurements can be incorporated into long-term ecological research and monitoring programs, resulting in advanced understanding of organic matter dynamics in aquatic ecosystems.

439 citations

Journal ArticleDOI
19 Apr 2013-Science
TL;DR: This study quantified dissolution products of charcoal in a wide range of rivers worldwide and shows that globally, a major portion of the annual charcoal production is lost from soils via dissolution and subsequent transport to the ocean.
Abstract: Global biomass burning generates 40 million to 250 million tons of charcoal every year, part of which is preserved for millennia in soils and sediments. We have quantified dissolution products of charcoal in a wide range of rivers worldwide and show that globally, a major portion of the annual charcoal production is lost from soils via dissolution and subsequent transport to the ocean. The global flux of soluble charcoal accounts to 26.5 ± 1.8 million tons per year, which is ~10% of the global riverine flux of dissolved organic carbon (DOC). We suggest that the mobilization of charcoal and DOC out of soils is mechanistically coupled. This study closes a major gap in the global charcoal budget and provides critical information in the context of geoengineering.

422 citations


Cited by
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MonographDOI
16 Dec 2004
TL;DR: The second edition of The Biomarker Guide as mentioned in this paper provides a comprehensive account of the role that biomarker technology plays both in petroleum exploration and in understanding Earth history and processes.
Abstract: The second edition of The Biomarker Guide is a fully updated and expanded version of this essential reference. Now in two volumes, it provides a comprehensive account of the role that biomarker technology plays both in petroleum exploration and in understanding Earth history and processes. Biomarkers and Isotopes in the Environment and Human History details the origins of biomarkers and introduces basic chemical principles relevant to their study. It discusses analytical techniques, and applications of biomarkers to environmental and archaeological problems. The Biomarker Guide is an invaluable resource for geologists, petroleum geochemists, biogeochemists, environmental scientists and archaeologists.

2,163 citations

Journal ArticleDOI
TL;DR: In this article, the authors focus on the transport and transformations of land-derived organic matter in the ocean, highlighting recent research on the patterns and processes involved in the degradation of terrestrial organic matter.

1,335 citations

Journal ArticleDOI
TL;DR: In this paper, the authors used excitation-emission matrix (EEM) spectroscopy, a sensitive technique that allows direct analysis of water samples, to better characterize DOM in the Gironde Estuary (southwestern France).

1,180 citations

Journal ArticleDOI
TL;DR: In this paper, the authors describe a new technique for sample preparation, accelerated solvent extraction (ASE), that combines elevated temperatures and pressures with liquid solvents, and investigate the effects of various operational parameters (i.e., temperature, pressure, and volume of solvent used) on the performance of ASE.
Abstract: We describe a new technique for sample preparation, accelerated solvent extraction (ASE), that combines elevated temperatures and pressures with liquid solvents. The effects of various operational parameters (i.e., temperature, pressure, and volume of solvent used) on the performance of ASE were investigated. The solvents used are those normally used for standard liquid extraction techniques like Soxhlet or sonication. We found the recoveries of polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and total petroleum hydrocarbons from reference materials using ASE to be quantitative. The extraction time for 1−30-g samples is less than 15 min, and the volume of solvent is 1.2−1.5 times that of the extraction cell containing the sample. No evidence was seen for thermal degradation during the extraction of temperature-sensitive compounds.

1,109 citations

Journal ArticleDOI
TL;DR: In this paper, the authors use fluorescence spectroscopy to provide a novel approach to understand the dynamics and biogeochemical role of dissolved organic matter (DOM) in aquatic ecosystems.
Abstract: The biochemical composition of dissolved organic matter (DOM) strongly influences its biogeochemical role in freshwater ecosystems, yet DOM composition measurements are not routinely incorporated into ecological studies. To date, the majority of studies of freshwater ecosystems have relied on bulk analyses of dissolved organic carbon and nitrogen to obtain information about DOM cycling. The problem with this approach is that the biogeochemical significance of DOM can only partially be elucidated using bulk analyses alone because bulk measures cannot detect most carbon and nitrogen transformations. Advances in fluorescence spectroscopy provide an alternative to traditional approaches for characterizing aquatic DOM, and allow for the rapid and precise characterization of DOM necessary to more comprehensively trace DOM dynamics. It is within this context that we discuss the use of fluorescence spectroscopy to provide a novel approach to tackling a longstanding problem: understanding the dynamics and biogeochemical role of DOM. We highlight the utility of fluorescence characterization of DOM and provide examples of the potential range of applications for incorporating DOM fluorescence into ecological studies in the hope that this rapidly evolving technique will further our understanding of the biogeochemical role of DOM in freshwater ecosystems.

1,029 citations