scholarly journals Spatial and seasonal variations in the composition of dissolved organic matter in a tropical catchment: the Lower Kinabatangan River, Sabah, Malaysia

2016 ◽  
Vol 18 (1) ◽  
pp. 137-150 ◽  
Author(s):  
Sahana Harun ◽  
Andy Baker ◽  
Chris Bradley ◽  
Gilles Pinay
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Seasonal Variations ◽  
Water Samples ◽  
River Catchment ◽  
Lower Kinabatangan

Dissolved organic matter (DOM) was characterised in water samples sampled in the Lower Kinabatangan River Catchment, Sabah, Malaysia between October 2009 and May 2010.

Seasonal variations of dissolved organic matter in the northern Adriatic Sea

1999 ◽  
Vol 64 (3) ◽  
pp. 153-169 ◽  
Author(s):  
M Pettine ◽  
L Patrolecco ◽  
M Manganelli ◽  
S Capri ◽  
M.G Farrace
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Seasonal Variations ◽  
Adriatic Sea ◽  
Northern Adriatic Sea ◽  
Northern Adriatic

scholarly journals Fast-freezing with liquid nitrogen preserves bulk dissolved organic matter concentrations, but not its composition

2016 ◽  
Author(s):  
Lisa Thieme ◽  
Daniel Graeber ◽  
Martin Kaupenjohann ◽  
Jan Siemens
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Liquid Nitrogen ◽  
Water Samples ◽  
Terrestrial Ecosystems ◽  
Spectroscopic Properties ◽  
Fluorescence Excitation ◽  
Total Fluorescence ◽  
Fluorescence Excitation Emission Matrices ◽  
Fast Freezing

Abstract. Freezing can affect concentrations and spectroscopic properties of dissolved organic matter (DOM) in water samples. Nevertheless, water samples are regularly frozen for sample preservation. In this study we tested the effect of different freezing methods (standard freezing at −18 °C and fast-freezing with liquid nitrogen) on DOM concentrations measured as organic carbon (DOC) concentrations and on spectroscopic properties of DOM from different terrestrial ecosystems (forest and grassland). Fresh and differently frozen throughfall, stemflow and soil solution samples were analyzed for DOC concentrations, UV-vis absorption and fluorescence excitation-emission matrices combined with parallel factor analysis (PARAFAC). Fast-freezing with liquid nitrogen prevented a significant decrease of DOC concentrations observed after freezing at −18 °C. Nonetheless, the share of PARAFAC components 1 (EXmax < 250 nm (340 nm), EMmax: 480 nm) and 2 (EXmax: 335 nm, EMmax: 408 nm) to total fluorescence and the humification index (HIX) decreased after both freezing treatments, while the shares of component 3 (EXmax: < 250 nm (305 nm), EMmax: 438 nm) as well as SUVA254 increased. The contribution of PARAFAC component 4 (EXmax: 280 nm, EMmax: 328 nm) to total fluorescence was not affected by freezing. We recommend fast-freezing with liquid nitrogen for preservation of bulk DOC concentrations of samples from terrestrial sources, whereas immediate measuring is preferable to preserve spectroscopic properties of DOM.

Monitoring seasonal variations of colored dissolved organic matter for the Saginaw River based on Landsat-8 data

2018 ◽  
Vol 19 (1) ◽  
pp. 274-281 ◽  
Author(s):  
Jiang Chen ◽  
Weining Zhu ◽  
Yuhan Zheng ◽  
Yong Q. Tian ◽  
Qian Yu
Keyword(s):  
Remote Sensing ◽  
Organic Matter ◽  
Environmental Factors ◽  
Dissolved Organic Matter ◽  
Spatial Resolution ◽  
Seasonal Variations ◽  
Pearson Correlation ◽  
Landsat 8 ◽  
Colored Dissolved Organic Matter ◽  
Positive Role

Abstract Remote sensing is an effective tool for studying CDOM (colored dissolved organic matter) variations and its relevant environmental factors. Monitoring CDOM distribution and dynamics in small water is often limited by the coarse spatial resolution of traditional ocean color sensors. In this study, because of its high spatial resolution of 30 m, Landsat-8 data were used to assess seasonal variations of CDOM in the Saginaw River, by using an empirical statistic model. Pearson correlation analysis between CDOM variations and other environmental factors, such as temperature, discharge, and dissolved oxygen, shows that temperature was negatively correlated to CDOM variations and discharge played a positive role. We also calculated the monthly mean aCDOM(440) (the absorption coefficient of CDOM at 440 nm) for the Saginaw River between April and November from 2013 to 2016. This study demonstrates a good example for future applications in small waters: observing CDOM variations and other relevant environmental factors change by using Landsat remote sensing, so that we can know more about water quality and ecosystem health of small waters as well as the climate change impact on regional watersheds.

Seasonal variations in the optical characteristics of dissolved organic matter in glacial pond water

2021 ◽  
Vol 759 ◽  
pp. 143464
Author(s):  
D. Vione ◽  
N. Colombo ◽  
D. Said-Pullicino ◽  
D. Bocchiola ◽  
G. Confortola ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Seasonal Variations ◽  
Pond Water ◽  
Optical Characteristics

scholarly journals Fast-freezing with liquid nitrogen preserves bulk dissolved organic matter concentrations, but not its composition

2016 ◽  
Vol 13 (16) ◽  
pp. 4697-4705 ◽  
Author(s):  
Lisa Thieme ◽  
Daniel Graeber ◽  
Martin Kaupenjohann ◽  
Jan Siemens
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Liquid Nitrogen ◽  
Water Samples ◽  
Terrestrial Ecosystems ◽  
Spectroscopic Properties ◽  
Fluorescence Excitation ◽  
Total Fluorescence ◽  
Litter Leachate ◽  
Fast Freezing

Abstract. Freezing can affect concentrations and spectroscopic properties of dissolved organic matter (DOM) in water samples. Nevertheless, water samples are regularly frozen for sample preservation. In this study we tested the effect of different freezing methods (standard freezing at −18 °C and fast-freezing with liquid nitrogen) on DOM concentrations measured as organic carbon (DOC) concentrations and on spectroscopic properties of DOM from different terrestrial ecosystems (forest and grassland). Fresh and differently frozen throughfall, stemflow, litter leachate and soil solution samples were analyzed for DOC concentrations, UV-vis absorption and fluorescence excitation–emission matrices combined with parallel factor analysis (PARAFAC). Fast-freezing with liquid nitrogen prevented a significant decrease of DOC concentrations observed after freezing at −18 °C. Nonetheless, the share of PARAFAC components 1 (EXmax < 250 nm (340 nm), EXmax: 480 nm) and 2 (EXmax: 335 nm, EXmax: 408 nm) to total fluorescence and the humification index (HIX) decreased after both freezing treatments, while the shares of component 3 (EXmax: < 250 nm (305 nm), EXmax: 438 nm) as well as SUVA254 increased. The contribution of PARAFAC component 4 (EXmax: 280 nm, EXmax: 328 nm) to total fluorescence was not affected by freezing. We recommend fast-freezing with liquid nitrogen for preservation of bulk DOC concentrations of samples from terrestrial sources, whereas immediate measuring is preferable to preserve spectroscopic properties of DOM.

scholarly journals Fluorescence analysis allows to predict the oxidative capacity of humic quinones in dissolved organic matter: implication for pollutant degradation

2020 ◽  
Author(s):  
Davide Palma ◽  
Edith Parlanti ◽  
Mahaut Sourzac ◽  
Olivier Voldoire ◽  
Aude Beauger ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Water Samples ◽  
Three Dimensional ◽  
Complex Mixture ◽  
Fluorescence Analysis ◽  
Oxidative Capacity ◽  
Reactive Species ◽  
Solar Light ◽  
Pollutant Degradation

AbstractDissolved organic matter (DOM) controls the degradation and sequestration of aquatic pollutants and, in turn, water quality. In particular, pollutant degradation is performed by oxidant species that are generated by exposure of DOM to solar light, yet, since DOM is a very complex mixture of poorly known substances, the relationships between potential oxidant precursors in DOM and their oxydative capacity is poorly known. Here, we hypothesized that production of oxidant species could be predicted using fluorescence analysis. We analysed water samples from an alluvial plain by fluorescence spectroscopy; the three-dimensional spectra were then decomposed into seven individual components using a multi-way algorithm. Components include a protein-like fluorophore, e.g. tryptophan-like and tyrosine-like, three humic fluorophores, 2-naphthoxyacetic acid, and a by-product. We compared component levels with the ability of water samples to generate reactive species under solar light. The results show a strong correlation between reactive species production and the intensity of two humic-like fluorophores assigned to reduced quinones. Monitoring these fluorophores should thus allow to predict the ability of DOM degradation of pollutants in surface waters.

Spatial and Seasonal Variations in Stream Water δ34S-Dissolved Organic Matter in Northern Sweden

2009 ◽  
Vol 43 (2) ◽  
pp. 447-452 ◽  
Author(s):  
Reiner Giesler ◽  
Louise Björkvald ◽  
Hjalmar Laudon ◽  
Carl-Magnus Mörth
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Seasonal Variations ◽  
Stream Water ◽  
Northern Sweden
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