Molecular size and spectral characterization of organic matter in a meromictic lake

Hall, Ken J.; Lee, G.F.

doi:10.1016/0043-1354(74)90161-4

Cited by 68 publications

(15 citation statements)

References 16 publications

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“…Buffle (1988) and Midorikawa and Tanoue (1998) pointed out that lower molecular mass fraction was linked to higher concentrations of carboxyl groups in freshwater. Functional groups (such as hydroxyl, methoxyl and carboxyl groups) can greatly enhance fluorescence intensity by increasing the transition probability between the singlet and ground states (Hall and Lee, 1974). Similarly, the shorter Ex/Em maxima and higher fluorescence intensity for lake ligands, may suggest that lake organic ligands were composed of higher proportion of low molecular weight masses with higher concentration of functional groups than river organic ligands.…”

Section: River Vs Lake Imac Ligandsmentioning

confidence: 99%

“…Ex maximum of natural DOM was shifted towards shorter wavelength with decreasing molecular weight, accompanied by an apparent increase in fluorescence efficiency (Hall and Lee, 1974;Ewald et al, 1988). The Ex/Em fluorescence intensity was reported to increase with decreasing molecular weight in soil, sedimentary and aquatic fulvic and humic substances (Levesque, 1972;Hall and Lee, 1974;McCreary and Snoeyink, 1980;Visser, 1984;Hayase and Tsubota, 1985), and natural organic ligands (Midorikawa and Tanoue, 1998). Buffle (1988) and Midorikawa and Tanoue (1998) pointed out that lower molecular mass fraction was linked to higher concentrations of carboxyl groups in freshwater.…”

Section: River Vs Lake Imac Ligandsmentioning

confidence: 99%

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Fluorescence properties of organic ligands for copper(II) in Lake Biwa and its rivers.

Midorikawa

Tanoue

2001

Geochem. J.

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Organic ligands for copper(II) were isolated from lake waters in Lake Biwa and its river waters by immobilized metal ion affinity chromatography (IMAC), and were characterized by three-dimensional excitation/emission matrix spectroscopy (3DEEM) and fluorescence quenching titration. The results show that the contribution of total organic ligands was 0.63-4.68% of the bulk dissolved organic matter (DOM), in terms of UV absorbance, in lake and river waters. Three characteristic excitation/emission (Ex/Em) fluorescence peaks were identified in organic ligands from both lake and river waters, at Ex/Em 310-330/ 374-434 nm (Peak A), 250/414-454 nm (Peak B), and 260-270/306-330 nm (Peak C). Peaks A and B were referred to as humic-like fluorescence, Peak C as protein-like fluorescence. All Ex/Em maxima of organic ligands in lake waters were shifted towards shorter wavelength, and the fluorescence intensities were higher than those in river waters. The results of fluorescence quenching titration show that the IMAC ligands were weak ligands, with conditional stability constants (logK′ CuL ) around 7.27 for river ligands, and 7.84-9.23 for lake ligands. The differences of fluorescence properties indicate the variability of fluorescent ligands between river terrestrial and lake aquatic environments. a significant role in the mobilization and transport of nutrients and pollutants (As, Zn, Cd, Pb, and Ce), and soil weathering in terrestrial ecosystems (Tegen and Dorr, 1996;Li and Shuman, 1997;Kalbitz and Wennrich, 1998). However, most previous studies have only provided concentrations and conditional stability constants of organic ligands, the fundamentals pertaining to the properties of organic ligands are poorly understood since they have never been isolated (Gordon et al., 1996; Tanoue, 1996, 1998).Immobilized metal ion affinity chromatography (IMAC) has been successfully applied to isolate organic ligands for copper(II) from estuarine, coastal and oceanic waters (Gordon, 1992; Gordon INTRODUCTIONNaturally occurring organic ligands have been extensively studied in terms of metal speciation in aquatic environments during the past decades (Tanoue and Midorikawa, 1995). In oceanic waters, copper speciation is controlled by complexation with organic ligands (Donat and Bruland, 1995). In freshwaters, there are at least three ligand classes with logK values ranging from 15 to 8.6 (Xue and Sunda, 1997), which may control the bioavailability, toxicity and speciation of copper. Organic ligands were also reported to be responsible for other trace metal speciation (e.g., Hg) in freshwater (Mantoura et al., 1978), and play 334 F. Wu et al. et al., 1996; Tanoue, 1996, 1998;Donat et al., 1997). 3DEEM and UV-VIS spectroscopy have been demonstrated to be useful methods for characterizing DOM in natural waters (Coble et al., 1990;Mopper and Schultz, 1993;Coble, 1996;Smith and Kramer, 1999;Del Castillo et al., 1999). Absorbing and fluorescing complexes such as humic substances and proteins were expected to be good candidates for organic li...

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Section: River Vs Lake Imac Ligandsmentioning

confidence: 99%

Section: River Vs Lake Imac Ligandsmentioning

confidence: 99%

Fluorescence properties of organic ligands for copper(II) in Lake Biwa and its rivers.

Midorikawa

Tanoue

2001

Geochem. J.

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“…They also have a greater complexing capacity for cations (Rashid 1971;Stevenson 1982 fractions and tended to coincide with the absorbance peaks or slightly higher volumes. This weak fluorescence of the HWM fractions may be due to the reduction of fluorescence (quenching) as result of binding of metal ions (Levesque 1972;Underdown et al 1981;Ryan & Weber 1982) or to a decrease in the carboxylic hydroxyl content (Hall & Lee 1974). Table 3 represents the maximum excitation and emission value for the LMW fractions.…”

Section: Resultsmentioning

confidence: 98%

Differentiation of some Venezuelan blackwater rivers based upon physico-chemical properties of their humic substances

Vegas-Vilarrúbia¹,

Paolini²,

Miragaya³

1988

Biogeochemistry

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Abstract. The dissolved humic substances of seven Venezuelan blackwater rivers, belonging to different tropical biogeographical regions, were analyzed. Fractionation using Sephadex gel together with an analysis of their fluorescence, absorbance and infrared spectral properties, showed differences between their humic substances. These differences were related to their biological sources and humification environment. Statistical analysis of the properties of these humic substances allowed us to separate the rivers into three groups. These groups were directly related to the geological features and vegetation of the terrestrial ecosystems into which they drain: -The Autana, Atabapo, Chola, Negro which belong to the Amazon basin on the Guayana Shield, each with typical blackwater riverine forest. -The Caroni, belonging to the Orinoco basin on the Guayana Shield and with tropical humid forest and rainforest. -The Morichal Largo which draines the Mesa Formation from the eastern Llanos and has gallery forest of MauririafZexuosa.

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“…The remaining 30 per cent was present as inorganic complexes. Hall and Lee (1974) have shown that if the iron content of the solution is small, the organic matter in natural water is in true solution, but as Fe(II1) is added to the system, the iron and organics combine together to form larger particles and tend to become colloidal in character. Thus, whether it is in a true solution or not depends directly on the concentration of iron present in the system.…”

Section: Introductionmentioning

confidence: 99%

The nature of iron and manganese species in dam waters

Chiswell

Zaw

1989

Hydrological Processes

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The molecular weight (M.W.) distributions of iron and manganese species in dam water samples were investigated by use of gel filtration, while the ion-exchangeable and non-ion-exchangeable fractions of these metals were also analysed by ion-exchange chromatography. For the samples studied, more than 96 per cent of the manganese species present were found to be ion-exchangeable, whilst less than 35 per cent of iron species were ion-exchangeable. These results correlated with the finding that all the manganese species had molecular weights less than 700, but that the molecular weights of the iron species were mostly in excess of 5000. Electron paramagnetic resonance (EPR) spectroscopy has been used to support the finding that manganese is almost totally present in the form of simple aquated Mn(I1) ions.

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Molecular size and spectral characterization of organic matter in a meromictic lake

Cited by 68 publications

References 16 publications

Fluorescence properties of organic ligands for copper(II) in Lake Biwa and its rivers.

Fluorescence properties of organic ligands for copper(II) in Lake Biwa and its rivers.

Differentiation of some Venezuelan blackwater rivers based upon physico-chemical properties of their humic substances

The nature of iron and manganese species in dam waters

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