TY - JOUR
T1 - Fluorescence characteristics of size-fractionated dissolved organic matter
T2 - Implications for a molecular assembly based structure?
AU - Romera-Castillo, Cristina
AU - Chen, Meilian
AU - Yamashita, Youhei
AU - Jaffé, Rudolf
N1 - Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2014/5/15
Y1 - 2014/5/15
N2 - Surface freshwater samples from Everglades National Park, Florida, were used to investigate the size distributions of natural dissolved organic matter (DOM) and associated fluorescence characteristics along the molecular weight continuum. Samples were fractionated using size exclusion chromatography (SEC) and characterized by spectroscopic means, in particular Excitation-Emission Matrix fluorescence modeled with parallel factor analysis (EEM-PARAFAC). Most of the eight components obtained from PARAFAC modeling were broadly distributed across the DOM molecular weight range, and the optical properties of the eight size fractions for all samples studied were quite consistent among each other. Humic-like components presented a similar distribution in all the samples, with enrichment in the middle molecular weight range. Some variability in the relative distribution of the different humic-like components was observed among the different size fractions and among samples. The protein like fluorescence, although also generally present in all fractions, was more variable but generally enriched in the highest and lowest molecular weight fractions. These observations are in agreement with the hypothesis of a supramolecular structure for DOM, and suggest that DOM fluorescence characteristics may be controlled by molecular assemblies with similar optical properties, distributed along the molecular weight continuum. This study highlights the importance of studying the molecular structure of DOM on a molecular size distribution perspective, which may have important implications in understanding the environmental dynamics such materials.
AB - Surface freshwater samples from Everglades National Park, Florida, were used to investigate the size distributions of natural dissolved organic matter (DOM) and associated fluorescence characteristics along the molecular weight continuum. Samples were fractionated using size exclusion chromatography (SEC) and characterized by spectroscopic means, in particular Excitation-Emission Matrix fluorescence modeled with parallel factor analysis (EEM-PARAFAC). Most of the eight components obtained from PARAFAC modeling were broadly distributed across the DOM molecular weight range, and the optical properties of the eight size fractions for all samples studied were quite consistent among each other. Humic-like components presented a similar distribution in all the samples, with enrichment in the middle molecular weight range. Some variability in the relative distribution of the different humic-like components was observed among the different size fractions and among samples. The protein like fluorescence, although also generally present in all fractions, was more variable but generally enriched in the highest and lowest molecular weight fractions. These observations are in agreement with the hypothesis of a supramolecular structure for DOM, and suggest that DOM fluorescence characteristics may be controlled by molecular assemblies with similar optical properties, distributed along the molecular weight continuum. This study highlights the importance of studying the molecular structure of DOM on a molecular size distribution perspective, which may have important implications in understanding the environmental dynamics such materials.
KW - EEM-PARAFAC
KW - Everglades
KW - Fluorescent DOM
KW - Molecular assemblies
KW - Size exclusion chromatography
UR - http://www.scopus.com/inward/record.url?scp=84896809640&partnerID=8YFLogxK
U2 - 10.1016/j.watres.2014.02.017
DO - 10.1016/j.watres.2014.02.017
M3 - 文章
C2 - 24602859
AN - SCOPUS:84896809640
VL - 55
SP - 40
EP - 51
JO - Water Research
JF - Water Research
SN - 0043-1354
ER -