Refine your search:     
Report No.
 - 
Search Results: Records 1-6 displayed on this page of 6
  • 1

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

Stoichiometry between humate unit molecules and metal ions in supramolecular assembly induced by Cu$$^{2+}$$ and Tb$$^{3+}$$ measured by gel electrophoresis techniques

Nakano, Sumika*; Marumo, Kazuki*; Kazami, Rintaro*; Saito, Takumi*; Haraga, Tomoko; Tasaki-Handa, Yuiko*; Saito, Shingo*

Environmental Science & Technology, 55(22), p.15172 - 15180, 2021/11

 Times Cited Count:1 Percentile:29.38(Engineering, Environmental)

Humic acid (HA) can strongly complex with metal ions to form a supramolecular assembly via coordination binding. However, determining the supramolecular size distribution and stoichiometry between small HA unit molecules constituting HA supramolecule and metal ions has proven to be challenging. Here, we investigated the changes in the size distributions of HAs induced by Cu$$^{2+}$$ and Tb$$^{3+}$$ ions using a unique polyacrylamide gel electrophoresis (PAGE) for the separation and quantification of HA complexes and metal ions bound, followed by UV-Vis spectroscopy and EEM-PARAFAC. It was found that the supramolecular behaviors of Cu$$^{2+}$$ and Tb$$^{3+}$$ complexes with HA collected from peat and deep groundwater (HHA) differed. Our results suggest that this supramolecular stoichiometry is related to the abundance of sulfur atoms in the elemental composition of HHA. Our results provide new insights into HA supramolecules formed via metal complexation.

Journal Articles

Advanced gel electrophoresis techniques reveal heterogeneity of humic acids based on molecular weight distributions of kinetically inert Cu$$^{2+}$$-humate complexes

Marumo, Kazuki*; Matsumoto, Atsumasa*; Nakano, Sumika*; Shibukawa, Masami*; Saito, Takumi*; Haraga, Tomoko; Saito, Shingo*

Environmental Science & Technology, 53(24), p.14507 - 14515, 2019/12

 Times Cited Count:2 Percentile:13.69(Engineering, Environmental)

Humic acids (HA) are responsible for the fate of metal ions in the environment. We developed a polyacrylamide gel electrophoresis (PAGE) technique to investigate the MW distributions of metal ion (copper ion). Combining contaminant-metal-free and high-resolution PAGE systems for HA provided accurate MW distributions for the metal ions. Coupling this system with UV-Vis spectrometry and the excitation-emission matrix (EEM) spectrometry-parallel factor analysis (PARAFAC) method revealed new insights into metal-HA complex. Interestingly, the MW distributions of the three metal ions were entirely different, indicating that the presence of specific binding environments in HA for the metal ions depending its MW. The MW distributions of five fluorescent components were associated with the metal ion distributions. Our PAGE-based methodology suggests that metal binding sites and fluorescent components in HA exhibit heterogeneity in terms of metal binding affinity and MW.

Oral presentation

Supramolecular formation of humic acids via complexation with metal ion investigated by two dimensional gel electrophoresis

Marumo, Kazuki*; Saito, Takumi*; Haraga, Tomoko; Shibukawa, Masami*; Saito, Shingo*

no journal, , 

no abstracts in English

Oral presentation

Aggregation reaction analysis of humic acids via complexation with lanthanide and actinide ions by means of two dimensional gel electrophoresis

Marumo, Kazuki*; Saito, Takumi*; Haraga, Tomoko; Shibukawa, Masami*; Saito, Shingo*

no journal, , 

no abstracts in English

Oral presentation

Evaluation for molecular weight distribution of actinide ions complexed with humic acid by gel electrophoresis

Haraga, Tomoko; Marumo, Kazuki*; Saito, Takumi*; Shibukawa, Masami*; Saito, Shingo*

no journal, , 

no abstracts in English

Oral presentation

Molecular weight distribution of actinide ions complexed with humic acid measured by gel electrophoresis techniques

Nakano, Sumika*; Marumo, Kazuki*; Haraga, Tomoko; Tasaki-Handa, Yuiko*; Saito, Shingo*

no journal, , 

no abstracts in English

6 (Records 1-6 displayed on this page)
  • 1