Complex Formation in the Region of Metal Hydrolysis and M(OH)₂ Precipitation. A Glass Electrode Potentiometric and Polarographic Study of Cd–(AMPSO)_x–(OH)_y and Zn–(AMPSO)_x–(OH)_y Systems

Abstract

The interaction between cadmium or zinc and AMPSO was investigated by DCP and GEP, at fixed total ligand to total metal concentration ratios and various pH values, at 25.0 8C and 0.1 M KNO 3 ionic strength. For Cd -(AMPSO) x -(OH) y system, CdL and CdL(OH) species, were identified, with stability constants values set to (as log b): 2.1 AE 0.1 and 6.2 AE 0.2, respectively. For Zn -(AMPSO) x -(OH) y system, the proposed final model with stability constants set to (as log b) is: ZnL ¼ 2.5 AE 0.1 and ZnL(OH) 2 ¼ 12.9 AE 0.2. For both systems, the fact that AMPSO deprotonation occurs in the metal hydrolysis and M(OH) 2 precipitation and the complexes formed are not too strong added a real challenge to data interpretation.

The inorganic speciation of tin(II) in aqueous solution

“…Above this pH, the lability of the complexes is lost, and we observed a strong decrease of the peak current, indicating the formation of insoluble, electrochemically inactive, hydrolytic species (Machado et al, 2006). This assumption was confirmed by cyclic voltammetry (CV) measurements, in which we did not observe the typical curve of a reversible process.…”

(Un)suitability of the use of pH buffers in biological, biochemical and environmental studies and their interaction with metal ions – a review

“…Studies about AMPSO complexation have shown that this buffer has the ability to bind with Ca, Co, Cu, Pb, Mg, Mn and Ni. 42,43,[62][63][64][65] …”

Biochemical Characterisation of Phage Pseudomurein Endoisopeptidases PeiW and PeiP Using Synthetic Peptides

“…This was not the case for PeiW in the presence of Mg 2+ where similar activities were seen at comparable pH values of Bistris propane buffer and Ampso (not shown). Ampso can form complexes with divalent metal ions [ 31 , 32 ]. The lower activity using Ampso in the presence of Ca 2+ may possibly be due to complex formation between Ca 2+ and Ampso, while there may not be complexes formed to the same extent between Mg 2+ and Ampso.…”