Contribution of capillary electrophoresis to an integrated vision of humic substances size and charge characterizations - CEA - Commissariat à l’énergie atomique et aux énergies alternatives Access content directly
Journal Articles Journal of Colloid and Interface Science Year : 2011

Contribution of capillary electrophoresis to an integrated vision of humic substances size and charge characterizations

Abstract

The physicochemical properties of three different humic substances (HS) are probed using capillary zone electrophoresis in alkaline carbonate buffers, pH 10. Special attention is drawn to the impact of the electrolyte ionic strength and counter-ion nature, chosen within the alkali-metal series, on HS electrophoretic mobility. Taylor-Aris dispersion analysis provides insights into the hydrodynamic radius (R$_H$) distributions of HS. The smallest characterized entities are of nanometric dimensions, showing neither ionic strength- nor alkali-metal-induced aggregation. These results are compared with the entities evidenced in dynamic light scattering measurements, the size of which is two order of magnitude higher, $ca$. 100 nm. The extended Onsager model provides a reasonable description of measured electrophoretic mobilities in the ionic strength range 1-50 mM, thus allowing the estimation of limiting mobilities and ionic charge numbers for the different HS samples. An unexpected HS electrophoretic mobility increase (in absolute value) is observed in the order Li$^+$ < Na$^+$ < K$^+$ < Cs$^+$ and discussed either in terms of retarding forces or in terms of ion-ion interactions.
Fichier principal
Vignette du fichier
111025_dOrlye_web .pdf (572.98 Ko) Télécharger le fichier
Origin : Files produced by the author(s)
Loading...

Dates and versions

cea-00663002 , version 1 (13-09-2019)

Licence

Attribution - NonCommercial - ShareAlike

Identifiers

Cite

Fanny d'Orlyé, Pascal E. Reiller. Contribution of capillary electrophoresis to an integrated vision of humic substances size and charge characterizations. Journal of Colloid and Interface Science, 2011, 368, pp.231-240. ⟨10.1016/j.jcis.2011.11.046⟩. ⟨cea-00663002⟩

Collections

CEA DEN DEN-SACLAY
68 View
111 Download

Altmetric

Share

Gmail Facebook X LinkedIn More