Fluorescence excitation-emission matrix regional integration to quantify spectra for dissolved organic matter.
15 Nov 2003-Environmental Science & Technology (American Chemical Society)-Vol. 37, Iss: 24, pp 5701-5710
TL;DR: Aromatic carbon and the presence of specific aromatic compounds resulted in EEMs that aided in differentiating wastewater effluent DOM from drinking water DOM, and the highest cumulative EEM volume was observed for hydrophobic neutral DOM fractions.
Abstract: Excitation−emission matrix (EEM) fluorescence spectroscopy has been widely used to characterize dissolved organic matter (DOM) in water and soil. However, interpreting the >10,000 wavelength-dependent fluorescence intensity data points represented in EEMs has posed a significant challenge. Fluorescence regional integration, a quantitative technique that integrates the volume beneath an EEM, was developed to analyze EEMs. EEMs were delineated into five excitation−emission regions based on fluorescence of model compounds, DOM fractions, and marine waters or freshwaters. Volumetric integration under the EEM within each region, normalized to the projected excitation−emission area within that region and dissolved organic carbon concentration, resulted in a normalized region-specific EEM volume (Φi,n). Solid-state carbon nuclear magnetic resonance (13C NMR), Fourier transform infrared (FTIR) analysis, ultraviolet−visible absorption spectra, and EEMs were obtained for standard Suwannee River fulvic acid and 15 h...
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TL;DR: This review focuses on the general properties of PCR inhibitors and their occurrence in specific matrices and strategies for their removal from the sample and for quality control by assessing their influence on the individual PCR test are presented.
Abstract: The polymerase chain reaction (PCR) is increasingly used as the standard method for detection and characterization of microorganisms and genetic markers in a variety of sample types. However, the method is prone to inhibiting substances, which may be present in the analysed sample and which may affect the sensitivity of the assay or even lead to false-negative results. The PCR inhibitors represent a diverse group of substances with different properties and mechanisms of action. Some of them are predominantly found in specific types of samples thus necessitating matrix-specific protocols for preparation of nucleic acids before PCR. A variety of protocols have been developed to remove the PCR inhibitors. This review focuses on the general properties of PCR inhibitors and their occurrence in specific matrices. Strategies for their removal from the sample and for quality control by assessing their influence on the individual PCR test are presented and discussed.
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Cites methods from "Fluorescence excitation-emission ma..."
...Different analytical methods can be used to determine the presence of inorganic or organic compounds, for example, the amount of dissolved organic carbon indicative for humic acids (Chen et al. 2003; Rock et al. 2010)....
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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 excitation-emission ma..."
...…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: An up-to-date review on recent research development in aerobic biogranulation technology and applications in treating toxic industrial and municipal wastewaters and attempts to shed light on the fundamental understanding in aerobic granulation by newly employed confocal laser scanning microscopic techniques and microscopic observations of granules.
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...Based on the classification scheme developed by Chen et al. (2003), peaks A, B, and C were in regions II (aromatic proteins), IV (soluble microbial by-product-like), and V (humic acid-like), respectively....
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TL;DR: Three-dimensional excitation-emission matrix (EEM) fluorescence spectroscopy was applied to characterize the extracellular polymeric substances (EPS) extracted from aerobic and anaerobic sludge in wastewater treatment.
627 citations
TL;DR: During long-term operation of the MBR, bound EPS demonstrated positive correlations with membrane fouling while temperature was verified as a negative factor affecting EPS concentration and loosely bound EPS (LB-EPS) showed more significant correlations with membranes fouling.
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References
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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
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: In this article, an investigation of the three-dimensional excitation-emission-matrix (EEM) fluorescence spectra of unconcentrated water samples collected in 1996, 1998 and 1999 at a site particularly propitious for macro-algae development was performed.
726 citations
TL;DR: In this paper, the authors present evidence from three-dimensional excitation emission matrix (EEM) spectroscopy that at least three fluorophores are present in waters of the Black Sea.
Abstract: THE natural fluorescence properties of sea water provide a means of elucidating the complex chemical composition and diverse sources of dissolved organic matter (DOM) in sea water1–6. The positions of excitation and emission maxima for a wide range of natural water samples show remarkable similarity7. High-sensitivity fluorescence spectroscopic studies8 have shown recently that emission maxima for marine and coastal waters differ by 20 nm when the excitation wavelength is 313 nm. Here we present evidence from three-dimensional excitation emission matrix (EEM) spectroscopy that at least three fluorophores are present in waters of the Black Sea. Distinct changes in the relative abundance of these fluorophores are observed as a function of depth. We suggest that three-dimensional fluorescence spectroscopy can be used to distinguish between different types and sources of DOM in natural waters. These findings may have important applications in the field of remote sensing of phytoplankton pigments. For example, a better understanding of the sources of DOM components will help in correcting9,10 remotely sensed data for the presence of gelbstoff (yellow-coloured DOM11, which plays an important part in radiation absorption by surface waters).
634 citations
TL;DR: Fifty samples of humic acids and fulvic acids isolated from various soils and soil-related materials (including paleosols, peat, leonardite, composted and earthworm-composted organic materials, sewage sludges, and materials synthesized by soil fungi) have been investigated by fluorescence spectrosc as mentioned in this paper.
Abstract: Fifty samples of humic acids and fulvic acids isolated from various soils and soil-related materials (including paleosols, peat, leonardite, composted and earth-worm-composted organic materials, sewage sludges, and materials synthesized by soil fungi) have been investigated by fluorescence spectrosc
586 citations