Related Experiment Video
Updated: Jul 17, 2026

Stable Aqueous Suspensions of Manganese Ferrite Clusters with Tunable Nanoscale Dimension and Composition
Published on: February 5, 2022
Size distribution, complexing capacity, and stability of phosphate-metal-humic complexes
Iñaki Guardado1, Oscar Urrutia, Jose M García-Mina
1Department of Chemistry and Soil Chemistry, University of Navarra, 31080 Pamplona, Spain.
Abstract:
Size distribution, maximum complexing ability, and stability constants for phosphate-metal-humic (PO43--M-HA) complexes involving two trivalent (Fe and Al) and five divalent metal (M) bridges (Zn, Cu, Mn, Ca, and Mg) were investigated at the pH values 4, 6, and 8. Results highlighted the existing competition between metal-humic acid (M-HA) aggregation and the formation of PO43--M-HA complexes. However, the fact that only a very low fraction of complexed metal is involved in PO43- fixation seems to be related to the existence of specific electronic and/or steric requirements in the binding site in the metal-humic complex. The importance of the ionic form of phosphate (H2PO4- or HPO42-) and the involvement of phenolic and especially carboxylic groups in the phosphate binding are discussed. Finally, the order of stability obtained for PO43--M-HA complexes was similar to that of M-HA complexes. This result suggests that PO43--M-HA might play a significant role in the dynamics of phosphorus in certain soil types.
More Related Videos
08:21Optimized Procedure for Determining the Adsorption of Phosphonates onto Granular Ferric Hydroxide using a Miniaturized Phosphorus Determination Method
Published on: May 18, 2018
07:20Discovery and Synthesis Optimization of Isoreticular Al(III) Phosphonate-Based Metal-Organic Framework Compounds Using High-Throughput Methods
Published on: October 6, 2023
Related Concept Videos
Complexation Equilibria: Factors Influencing Stability of Complexes
Complexation Equilibria: The Chelate Effect
Complexometric Titration: Ligands
Extraction: Advanced Methods
EDTA: Chemistry and Properties
Phosphate Buffer
Sodium dihydrogen phosphate does not fully dissociate in neutral or acidic solutions. When a strong base, such as sodium hydroxide (NaOH), is introduced into the solution, sodium dihydrogen phosphate...