Fluorescence spectroscopic studies of natural organic matter fractions.
TL;DR: S synchronous spectral peak intensity and its red shift in the region of about 450-480 nm may be used to indicate the presence or absence of high molecular weight and polycondensed humic organic components, or the multicomponent nature of NOM or NOM subcomponents.
About: This article is published in Chemosphere.The article was published on 2003-02-01. It has received 411 citations till now. The article focuses on the topics: Humic acid & Fluorescence spectroscopy.
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TL;DR: It is concluded that the sensitive detection of contamination events in recycled water systems may be achieved by monitoring Peak T and/or Peak C fluorescence.
845 citations
Cites background from "Fluorescence spectroscopic studies ..."
...…typical of those exhibited by soluble microbial products (SMP) and extracellular polymeric substances (EPS) and as such comprise Peaks T1, T2 and C1, but not C2 (Esparza-Soto and Westerhoff, 2001; Westerhoff et al., 2001; Chen et al., 2003b; Her et al., 2003; Lee and Ahn, 2004; Sheng and Yu, 2006)....
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...Chen et al. (2003b) divided wastewater EEMs into five operationally defined sections associated with peaks of different compound types and integrated and normalised the data within these boundaries....
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...…have been explained by the fragmentation of humic substance since previous research has shown that fluorescence enhancement can be associated with w a t e r r e s e a r c h 4 3 ( 2 0 0 9 ) 8 6 3 – 8 8 1 875 a decrease in average molecular weight (Peuravuori et al., 2002; Chen et al., 2003a)....
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...Such differences in spectral signatures have facilitated the tracking of sewage contamination in river waters (Galapate et al., 1998; Baker, 2001; Baker et al., 2003; Chen et al., 2003b; Baker et al., 2005; Holbrook et al., 2005; Hudson et al., 2008)....
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TL;DR: In this paper, an attempt was made to degrade aniline in the synthetic effluent by homogeneous and heterogeneous Fenton oxidation process under the batch and continuous operating conditions.
517 citations
University of Tübingen1, Nanjing Agricultural University2, University of New South Wales3, University of Newcastle4, Ithaka Harbors5, Colorado State University6, University of New Hampshire7, Florida State University8, Cooperative Research Centre9, University of Bayreuth10, University of Palermo11, Technical University of Berlin12, University of Minnesota13
TL;DR: This work identifies a complex, nutrient-rich organic coating on co-composted biochar that covers the outer and inner (pore) surfaces of biochar particles using high-resolution spectro(micro)scopy and mass spectrometry, which strengthens biochar-water interactions and thus enhances nutrient retention.
Abstract: Amending soil with biochar (pyrolized biomass) is suggested as a globally applicable approach to address climate change and soil degradation by carbon sequestration, reducing soil-borne greenhouse-gas emissions and increasing soil nutrient retention. Biochar was shown to promote plant growth, especially when combined with nutrient-rich organic matter, e.g., co-composted biochar. Plant growth promotion was explained by slow release of nutrients, although a mechanistic understanding of nutrient storage in biochar is missing. Here we identify a complex, nutrient-rich organic coating on co-composted biochar that covers the outer and inner (pore) surfaces of biochar particles using high-resolution spectro(micro)scopy and mass spectrometry. Fast field cycling nuclear magnetic resonance, electrochemical analysis and gas adsorption demonstrated that this coating adds hydrophilicity, redox-active moieties, and additional mesoporosity, which strengthens biochar-water interactions and thus enhances nutrient retention. This implies that the functioning of biochar in soil is determined by the formation of an organic coating, rather than biochar surface oxidation, as previously suggested. Biochar promotes plant growth via a slow release of nutrients; however, a mechanistic understanding of nutrient storage in biochar is lacking. Here, using high-resolution spectromicroscopy and mass spectrometry, the authors identify an organic coating on co-composted particles that enhances nutrient retention.
332 citations
TL;DR: It is shown in this study that with selected lambda(ex), lambda(em) and (delta)(lambda) values, regular emission, excitation and synchronous spectra can, together, provide a good picture of the OM sources and aging for extracted HS.
303 citations
TL;DR: In this paper, a systematic synthesis of literature data on potentially relevant biological fluorophores was provided for the detection of fluorescent biological aerosol particles (FBAP) by online instrumentation for atmospheric measurements such as the ultraviolet aerodynamic particle sizer (UV-APS) or the wide issue bioaerosol sensor (WIBS).
Abstract: . Primary biological aerosol particles (PBAP) are an important subset of air particulate matter with a substantial contribution to the organic aerosol fraction and potentially strong effects on public health and climate. Recent progress has been made in PBAP quantification by utilizing real-time bioaerosol detectors based on the principle that specific organic molecules of biological origin such as proteins, coenzymes, cell wall compounds and pigments exhibit intrinsic fluorescence. The properties of many fluorophores have been well documented, but it is unclear which are most relevant for detection of atmospheric PBAP. The present study provides a systematic synthesis of literature data on potentially relevant biological fluorophores. We analyze and discuss their relative importance for the detection of fluorescent biological aerosol particles (FBAP) by online instrumentation for atmospheric measurements such as the ultraviolet aerodynamic particle sizer (UV-APS) or the wide issue bioaerosol sensor (WIBS). In addition, we provide new laboratory measurement data for selected compounds using bench-top fluorescence spectroscopy. Relevant biological materials were chosen for comparison with existing literature data and to fill in gaps of understanding. The excitation-emission matrices (EEM) exhibit pronounced peaks at excitation wavelengths of ~280 nm and ~360 nm, confirming the suitability of light sources used for online detection of FBAP. They also show, however, that valuable information is missed by instruments that do not record full emission spectra at multiple wavelengths of excitation, and co-occurrence of multiple fluorophores within a detected sample will likely confound detailed molecular analysis. Selected non-biological materials were also analyzed to assess their possible influence on FBAP detection and generally exhibit only low levels of background-corrected fluorescent emission. This study strengthens the hypothesis that ambient supermicron particle fluorescence in wavelength ranges used for most FBAP instruments is likely to be dominated by biological material and that such instrumentation is able to discriminate between FBAP and non-biological material in many situations. More detailed follow-up studies on single particle fluorescence are still required to reduce these uncertainties further, however.
277 citations
Cites background from "Fluorescence spectroscopic studies ..."
...…spectra, particularly EEMs, of humic and fulvic acids provide chemical and structural information such as conformation and functional groups (Chen et al., 2003), molecular weight (Stewart and Wetzel, 1980), aromatic character (Mi- no et al., 1988) and oxidation state (Klapper et al., 2002)....
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...It is reported that the fluorescence spectra, particularly EEMs, of humic and fulvic acids provide chemical and structural information such as conformation and functional groups (Chen et al., 2003), molecular weight (Stewart and Wetzel, 1980), aromatic character (Mino et al....
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...Humic and fulvic acids in solution exhibit broad modes (390/490, 450/520), but with relatively low intensity and resemble fluorescence behavior of DOM (e.g. Chen et al., 2003; Wedborg et al., 2007)....
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References
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TL;DR: A key to pharmaceutical and medicinal chemistry literature and training of literature chemists are discussed in the Advances series as mentioned in this paper, with the focus on the training of chemistry chemists, which is a subject of great interest to the literature chemist.
Abstract: NUMBERS 16 and 17 in the Advances series have made their appearance. The titles are: "A Key to Pharmaceutical and Medicinal Chemistry Literature" and "Training of literature Chemists." The first is a collection of papers presented before the Divisions of Chemical Literature and Medicinal Chemistry; the second consists of papers given before a joint meeting of the Divisions of Chemical Education and Chemical Literature. Glancing at the titles of subjects covered to date in the Advances series, it becomes evident that a substantial literature is being built by literature chemists, largely through the divisions in the AMERICAN CHEMICAL SOCIETY. Number 4, "Searching the Chemical Literature," has been reprinted several times and frequently is referred to as the "bible" of literature chemists. Number 10, "Literature Resources for Chemical Process Industries," is in much demand. Nomenclature is a subject of direct importance to the literature chemist, and Number 8, entitled "Chemical Nomenclature," and ...
3,188 citations
TL;DR: In this paper, high-resolution fluorescence spectroscopy was used to characterize dissolved organic matter (DOM) in concentrated and unconcentrated water samples from a wide variety of freshwater, coastal and marine environments.
3,004 citations
"Fluorescence spectroscopic studies ..." refers background in this paper
...It has been shown that the fluorescence of dissolved organic matter accounts for a significant portion of the fluorescence in both natural fresh and oceanic water samples (Stewart and Wetzel, 1980; Lochmuller and Saavedra, 1986; Ewald and Belin, 1987; Mopper and Schultz, 1993; Coble, 1996 )....
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TL;DR: In this article, the authors studied the fluorescence properties of fulvic acids isolated from streams and rivers receiving predominantly terrestrial sources of organic material and from lakes with microbial sources, and showed that the ratio of the emission intensity at a wavelength of 450 nm to that at 500 nm, obtained with an excitation of 370 nm, can serve as a simple index to distinguish sources of isolated aquatic fulvic acid.
Abstract: We studied the fluorescence properties of fulvic acids isolated from streams and rivers receiving predominantly terrestrial sources of organic material and from lakes with microbial sources of organic material. Microbially derived fulvic acids have fluorophores with a more sharply defined emission peak occurring at lower wavelengths than fluorophores in terrestrially derived fulvic acids. We show that the ratio of the emission intensity at a wavelength of 450 nm to that at 500 nm, obtained with an excitation of 370 nm, can serve as a simple index to distinguish sources of isolated aquatic fulvic acids. In our study, this index has a value of ;1.9 for microbially derived fulvic acids and a value of ;1.4 for terrestrially derived fulvic acids. Fulvic acids isolated from four large rivers in the United States have fluorescence index values of 1.4‐1.5, consistent with predominantly terrestrial sources. For fulvic acid samples isolated from a river, lakes, and groundwaters in a forested watershed, the fluorescence index varied in a manner suggesting different sources for the seepage and streamfed lakes. Furthermore, we identified these distinctive fluorophores in filtered whole water samples from lakes in a desert oasis in Antarctica and in filtered whole water samples collected during snowmelt from a Rocky Mountain stream. The fluorescence index measurement in filtered whole water samples in field studies may augment the interpretation of dissolved organic carbon sources for understanding carbon cycling in aquatic ecosystems.
2,428 citations
TL;DR: Data indicate that aquatic fulvic acids, a commercial humic acid, and unfractionated organic matter from four natural water samples are smaller and less polydisperse than previously believed.
Abstract: The number- and weight-averaged molecular weights of a number of aquatic fulvic acids, a commercial humic acid, and unfractionated organic matter from four natural water samples were measured by high-pressure size exclusion chromatography (HPSEC). Molecular weights determined in this manner compared favorably with those values reported in the literature. Both recent literature values and our data indicate that these substances are smaller and less polydisperse than previously believed. Moreover, the molecular weights of the organic matter from three of the four natural water samples compared favorably to the fulvic acid samples extracted from similar environments
1,657 citations
TL;DR: Results indicated that ligand exchange between carboxyl/hydroxyl functional groups of NOM and iron oxide surfaces was the dominant interaction mechanism, especially under acidic or slightly acidic pH conditions.
Abstract: This study was undertaken to elucidate the interaction mechanism between NOM (natural organic matter) and iron oxide surfaces and to develop a predictive model for NOM adsorption and desorption. Results indicated that ligand exchange between carboxyl/hydroxyl functional groups of NOM and iron oxide surfaces was the dominant interaction mechanism, especially under acidic or slightly acidic pH conditions. This conclusion was supported by the measurements of heat of adsorption (microcalorimetry), FTIR and [sup 18]C NMR analysis, and competitive adsorption between NOM and some specifically adsorbed anions. A modified Langmuir model was proposed in which a surface excess-dependent affinity parameter was defined to account for a decreasing adsorption affinity with surface coverage due to the heterogeneity of NOM and adsorbent surfaces. With three adjustable parameters, the model is capable of describing a variety of adsorption isotherms. A hysteresis coefficient, h, was used to describe the hysteretic effect of adsorption reactions that, at h = 0, the reaction is completely reversible, whereas at h = 1, the reaction is completely irreversible. Fitted values of h for NOM desorption on iron oxide surfaces ranged from 0.72 to 0.92, suggesting that the adsorbed NOM was very difficult to be desorbed at a given pH andmore » ionic composition. 54 refs., 8 figs., 3 tabs.« less
1,340 citations
"Fluorescence spectroscopic studies ..." refers background or result in this paper
...aquatic NOM (hereinafter referred to as GT-NOM) obtained from a wetland pond ( Gu et al., 1994, 2002 ), a soil humic acid (Soil HA) and a Suwannee River fulvic acid (SRFA) obtained from IHSS....
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...The spectra of the reference SRFA and GT-NOM (not shown) resembled each other, suggesting similar chemical characteristics between the SRFA and GT-NOM organic materials, as reported previously ( Gu et al., 1994, 1995 )....
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