Electrophoretic aggregation of humic acid

Übner, Monika; Lepane, Viia; Lopp, Margus; Kaljurand, Mihkel

doi:10.1016/j.chroma.2004.06.018

Cited by 13 publications

(7 citation statements)

References 25 publications

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“…All three peaks were superimposed on a broad background, which is frequently referred to as a humic "hump" (Garrison et al, 1995;Schmitt-Kopplin and Junkers, 2003). Other randomly appearing vertical lines (spikes) in the electropherograms were due to air bubbles in the buffer, aggregation of humic substances, and/or other artifacts which were of no relevance or interest (Ubner et al, 2004). Comparing the CE profi les in the three types of samples, a broader third peak (or stronger trailing) was observed in FA samples.…”

Section: Capillary Electrophoresis Profi Les Of Ihss Samplesmentioning

confidence: 99%

“…They are important contributors to the global cycles of C, N, P, and S in the bioand geospheres (Schmitt-Kopplin and Junkers, 2003). Because of their ability to interact with various components of the envi-ronment, humic substances play important roles in soil and aquatic chemical processes and therefore have attracted the attention of soil and environmental chemists (Schmitt et al, 1997;Xing, 2001;Janos, 2003;Ubner et al, 2004;Wang and Xing, 2005;He et al, 2006;Makarov and Malysheva, 2006;Muscolo et al, 2007). As humic substances are complex, heterogeneous, and polydisperse mixtures of non-stoichiometric composition, the investigation on their structure and function remains a signifi cant challenge in modern analytical chemistry different among the FA, HA, and unprocessed NOM samples.…”

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confidence: 99%

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Capillary Electrophoresis and Fluorescence Excitation‐Emission Matrix Spectroscopy for Characterization of Humic Substances

Ohno

et al. 2008

Soil Science Soc of Amer J

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Capillary electrophoresis (CE) and fluorescence spectroscopy have been used in natural organic matter (NOM) studies. In this study, we characterized five fulvic acids (FAs), six humic acids (HAs), and two unprocessed NOM samples obtained from the International Humic Substances Society (IHSS) using these two analytical methods. The electropherograms of all samples revealed three peak features. The first and third peaks were sharp. The second peak had a broad, hump‐shaped feature. The pattern and shapes of these peaks were different among the FA, HA, and unprocessed NOM samples. Excitation‐emission matrix (EEM) fluorescence spectroscopic analysis revealed that each of the 13 investigated samples contained four components. However, the relative amounts of the four components varied with sample origin. Autoclaving these samples for 1 h (heat decomposition) produced additional CE peaks and changed portions of the four fluorophore components, indicating that both methods can be used to investigate the dynamics of NOM decomposition. Although four fluorophore components were present in each of the three CE fractions, their relative abundances varied among the three CE fractions. Specifically, Fraction 1 and 2 were rich in Component 1 and 4, but sparse in Component 2, compared with their original samples. Fraction 2 also contained less Component 3. The distribution of the four components in Fraction 3 was similar to that of the original samples. The mutual relevance of data collected from each of the two methods provided novel insight into the correlation of complex NOM fluorescence spectra to specific NOM fractions.

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Section: Capillary Electrophoresis Profi Les Of Ihss Samplesmentioning

confidence: 99%

mentioning

confidence: 99%

Capillary Electrophoresis and Fluorescence Excitation‐Emission Matrix Spectroscopy for Characterization of Humic Substances

Ohno

et al. 2008

Soil Science Soc of Amer J

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“…Capillary electrophoresis (CE) has been found to be one of the most efficient methods for characterization of HA [26,27]. Due to its high sensitivity and efficiency, some physicochemical properties, i.e., aggregation and stability have been studied using this technique [28]. However, despite the high number of studies done and reported in the literature, information concerning the mechanisms of interaction between these pollutants with HA is not well understood and needs to be clarified.…”

Section: Introductionmentioning

confidence: 99%

Effect of humic acids on the adsorption of paraquat by goethite

Brigante

Zanini

Avena

2010

Journal of Hazardous Materials

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“…Ubner et al [182] used CE to characterize HAs electrophoretic aggregation process. In general, the electropherograms of HAs contained two or more humps, and frequently, multiple randomly scattered sharp peaks (or spikes) superimposed on these humps.…”

Section: Humic Substances (Hs)mentioning

confidence: 99%