the complexation reactions between cu2+, pd2+ and ni2+ metal ions with promethazine (pm) in water or dmf were studied by the spectrophotometric methods at [(15, 25,35 and 45±0.1) °c]. the complexation process was optimized in terms of ph, temperature and contact time. the stoichiometry of the complex was found to be 1:1 (metal ion/ligand). the formation constants of the resulting complexes were...

The protonation constant values of salicylic and 5-nitrosalicylic acid werestudied by a combinationof spectrophotometric and potentiometric methods at 25 °C in wide range of ionic strength. The ionicstrength of solutions was kept constant by sodium perchlorate as background electrolyte at 0.10 to 3.0 moldm-3. Potentiometer was calibrated according to Gran method at each of ionic strength. The p...

The protonation constants of DTPA (diethylenetriaminepentaacetic acid) and two derivatives of DTPA, 1-R(4,4diphenyl cyclohexyl-phosphonyl-methyl diethylenentriaminepentaacetic acid (MS-325) and (R)-hydroxymethyl-diethylenentriaminepentaacetic acid (HMDTPA) were determined by potentiometric titration in 0.1 M NaClO4. The formation of 1 : 1 complexes of Am3+, Cm3+ and Ln3+ cations with these thre...

The solubility of CO2 in the primary, secondary, tertiary and sterically hindered amine aqueous solutions at various conditions was studied. In the present work, the Modified Kent-Eisenberg (M-KE), the Extended Debye-Hückel (E-DH) and the Pitzer models were employed to study the solubility of CO2 in amine aqueous solutions. Two explicit equations are presented to evalu...

In this study, a potentiometric titration was performed to investigate the surface acid–base properties of Pseudomonas pseudoalcaligenes isolated from activated sludge. Batch sorption as a function of pH was performed to explain the sorption behaviour of Cu(II) and Pb(II) ions onto the bacterial surface. The surface complexation approach in the frame of constant capacitance model was applied to...

The ingenious combination of lactate and diethylenetriamine-N,N,N’,N”,N”pentaacetic acid (DTPA) as an aqueous actinide-complexing medium forms the basis of the successful separation of americium and curium from lanthanides known as the TALSPEAK process. While numerous reports in the prior literature have focused on the optimization of this solvent extraction system, considerably less attention ...

This article shows that the introduction of the Surface Complexation model into the »family« of theories that comprise the Theory of Colloid Stability makes that theory »absolute«. This means that one characterizes the electrical interfacial layer, e.g. by adsorption measurements, and calculates the equilibrium parameters, such as the equilibrium constants of protonation and deprotonation of am...

Equilibria of the reaction of molybdenum(VI) with L-aspartic acid (Asp) and L- Glutamic acid(Glu) have been studied by spectrophotometric measurements in mixed solvent systems at an ionicstrength of 0.2 mol/dm3 sodium perchlorate, employed (15, 20, 25, 30± 0.1°C) at pH ranges of 3.2to 5.5 with a high ratio of ligand to metal. The stability constants of the complexes and theresulting free energy...

the complexation reactions between methylthymol blue (mtb) and co2+, ni2+, cu2+, zn2+ and pb2+ ions have been studied in different water-methanol mixtures at ph 4.45 and 25 °c by a spectrophotometric technique. the stepwise stability constants of the resulting 1:1 and 2:1 (metal ion to ligand) complexes were determined from the absorbance-mole ratio data. it was found that the overall stability...