scholarly journals Characteristics of dissolved organic matter in shallow groundwater in the Hetao basin

2019 ◽  
Vol 98 ◽  
pp. 02009
Author(s):  
Wen Qiao ◽  
Huaming Guo ◽  
Quan Shi ◽  
Bo Zhao
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Shallow Groundwater ◽  
Lower Proportion ◽  
The Other ◽  
Molecular Characteristics ◽  
Other Hand ◽  
Ft Icr Ms ◽  
Ft Icr

Dissolved organic matter (DOM) in both high As groundwater and low As groundwater were sampled from the Hetao basin and characterized by FT-ICR-MS for OM molecular characteristics. Results show that the greater number of molecular formulas was identified in DOM of high As groundwater (5125), compared to the number in DOM of low As groundwater (3603). Among them, lignins and aromatic structures were the most abundant compounds in both high As groundwater and low As groundwater, with 4434 formulas and 2944 formulas identified, respectively. The number of biodegradable compounds (aliphatic/proteins, lipids, and carbohydrates) was less in high As groundwater (197) than that in low As groundwater (279). Higher proportion of lignins and aromatic structures (86.5%) would lead to complexation between As and DOM, which enhanced As mobility. On the other hand, higher proportion of lignins and aromatic structures and lower proportion of bioavailable compounds in high As groundwater supported the hypothesis that more bioavailable compounds were consumed and resulted in the enrichment of lignins and aromatic structures and As release into groundwater.

Diverse molecular compositions of dissolved organic matter derived from different composts using ESI FT-ICR MS

2021 ◽  
Vol 99 ◽  
pp. 80-89 ◽  
Author(s):  
Minru Liu ◽  
Yunkai Tan ◽  
Kejing Fang ◽  
Changya Chen ◽  
Zhihua Tang ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Ft Icr Ms ◽  
Ft Icr

Automated microextraction sample preparation coupled on-line to FT-ICR-MS: application to desalting and concentration of river and marine dissolved organic matter

2009 ◽  
Vol 395 (3) ◽  
pp. 797-807 ◽  
Author(s):  
Gabriel Morales-Cid ◽  
Istvan Gebefugi ◽  
Basem Kanawati ◽  
Mourad Harir ◽  
Norbert Hertkorn ◽  
...  
Keyword(s):  
Organic Matter ◽  
Sample Preparation ◽  
Dissolved Organic Matter ◽  
On Line ◽  
Ft Icr Ms ◽  
Ft Icr

Understanding the structural complexity of dissolved organic matter: isomeric diversity

2019 ◽  
Vol 218 ◽  
pp. 431-440 ◽  
Author(s):  
Dennys Leyva ◽  
Lilian V. Tose ◽  
Jacob Porter ◽  
Jeremy Wolff ◽  
Rudolf Jaffé ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Structural Complexity ◽  
Ft Icr Ms ◽  
Ft Icr

In the present work, the advantages of ESI-TIMS-FT-ICR MS to address the isomeric content of dissolved organic matter are studied.

Resolution of photo chemically induced changes of dissolved organic matter as function of cumulated radiation in a sample of a humic-rich and forested stream

2020 ◽  
Author(s):  
Peter Herzsprung ◽  
Christin Wilske ◽  
Wolf von Tümpling ◽  
Norbert Kamjunke ◽  
Oliver J. Lechtenfeld
Keyword(s):  
Drinking Water ◽  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Fluorescence Intensity ◽  
Solar Irradiation ◽  
Large Reservoir ◽  
Photo Degradation ◽  
Peak Intensity ◽  
Ft Icr Ms ◽  
Ft Icr

<p>Photochemical processing is a major transformation pathway for allochthonous and autochthonous dissolved organic matter (DOM). DOM consists of thousands or even millions of different molecules and the isomer-resolved identification molecular structures is still far from any analytical realization. The highest analytical resolution of DOM can be achieved on a molecular mass basis via Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). With this technique, the molecular elemental compositions of thousands of DOM components can be assessed, given that they are extractable from water (via e.g. solid phase extraction, SPE-DOM) and ionizable (e.g. via electrospray ionization).</p><p>Increasing levels of DOC in drinking water reservoirs pose serious challenges for drinking water processing. Photochemical processes potentially influence the DOM quality in the reservoir water. The photo degradation and / or the photo production of DOM components in surface freshwater as function of cumulated radiation was rarely investigated. In order to fill this gap we performed an irradiation experiment with water from a shaded forest stream flowing into a large reservoir (Muldenberg, Germany). DOC concentration, UV absorption, excitation-emission-matrices (EEMs) including calculated PARAFAC components and fluorescence indices, and FT-ICR MS derived molecular formulas of SPE-DOM were recorded at 13 different time points. The cumulated radiation was recorded during six days of solar irradiation (sunny days in August at 50.401847 deg. latitude and 12.380528 deg. longitude). Changes in relative peak intensity of DOM components as function of cumulated radiation were evaluated both by Spearman`s rank correlation and linear regression.</p><p>We found components with different types of photo reaction behavior. Relative aliphatic components like C<sub>9</sub>H<sub>12</sub>O<sub>5</sub> were identified as photo products showing a monotonous mass peak intensity increase with irradiation time. Highly unsaturated and oxygen-rich components like C<sub>15</sub>H<sub>6</sub>O<sub>8</sub> showed a more or less monotonous intensity decrease indicating photo degradation. Many similar components were positively correlated to the humic-like fluorescence intensity and the humification index (HIX). The strong degradation of these components can explain the high loss of fluorescence intensity and the drop of the HIX in our experiment. As a result of the high temporal resolution in our experiment (i.e. intensity change as function of cumulated irradiation) we found another type of photo reaction. Components like C<sub>15</sub>H<sub>16</sub>O<sub>8</sub> showed first increasing and then decreasing intensity indicating the formation of intermediate products.</p><p>In general, the river DOM from the forested catchment area showed high potential for photochemical transformations which probably occur in the sunlight exposed predam of the drinking water reservoir.</p>

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