Equilibrium studies in natural fluids: interactions of -PO43−, -P2O74−and -P3O105−with the major constituents of sea water

Stefano, Concetta De; Foti, Claudia; Gianguzza, Antonio; Piazzese, Daniela

doi:10.3184/095422998782775871

Cited by 19 publications

(8 citation statements)

References 25 publications

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“…For example, in a recent study on the protonation of linear polyamines in synthetic seawater [39] we showed that for n>3 (n=number of protonated amino groups) this simplified approach does not hold, probably due to the formation of several weak mixed species. Some other classes of ligands, namely polyphosphates, carboxylates and amino acids, have been studied in this laboratory in synthetic seawater to provide quanti-964 tative information on the interaction of these ligands with the major inorganic constituents of seawater [40,41,42,43].…”

Section: Resultsmentioning

confidence: 99%

Interactions of diethylenetriaminepentaacetic acid (dtpa) and triethylenetetraaminehexaacetic acid (ttha) with major components of natural waters

Stefano¹,

Gianguzza²,

Piazzese³

et al. 2003

Anal Bioanal Chem

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The binding ability of diethylene triamine pentaacetate (dtpa(5-)) and triethylene tetraamine hexaacetate (ttha(6-)) ligands towards major components, H(+), Na(+), Mg(2+) and Ca(2+), of natural waters was studied in both single and mixed ionic media at different ionic strengths and at T=25 degrees C. Some measurements, performed in Mg(2+)-Ca(2+) mixtures, allowed us to find the formation of new mixed species MgCa(dtpa), MgCa(ttha) and MgCaH(ttha), here reported for the first time. All the complexes formed in the various systems were characterized in terms of both stoichiometry and stability, and an attempt was made to find general rules for the stability of mixed metal complexes in comparison with that of simple species. To obtain quantitative information on the complexing ability of dtpa and ttha in seawater, measurements have been carried out in artificial seawater ionic medium (Na(+), K(+), Ca(2+), Mg(2+), Cl(-) and SO(4)(2-)). Calculations, performed by considering the salt mixture as single salt BA, allowed us to find some quite stable B(i)H(j)L species. Under the natural seawater conditions [S(salinity)=35], we found for the most important species logbeta( B(dtpa))=9.64 and. Literature data comparison is also reported.

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Section: Resultsmentioning

confidence: 99%

Interactions of diethylenetriaminepentaacetic acid (dtpa) and triethylenetetraaminehexaacetic acid (ttha) with major components of natural waters

Stefano¹,

Gianguzza²,

Piazzese³

et al. 2003

Anal Bioanal Chem

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“…(see also some compilation [23][24][25][26][27]. In some previous papers we reported several thermodynamic data on LMW polycarboxylates 5,[19][20] , polyamines 8 , aminoacids [6][7] , inorganic polyanions [28][29][30] and HMW polycarboxylates 17,18,20,23,[31][32][33][34][35][36] in synthetic seawater and other ionic media, by studying also the dependence of protonation and formation constants on temperature, ionic media, ionic strength and molecular weight [35][36] . Results were also collected in a book chapter 21 , which includes also data about the dependence on salinity of hydrolysis constants of metal and organometal cations [37][38][39][40] .…”

Section: Introductionmentioning

confidence: 99%

The Protonation of Polyacrylate in Seawater. Analysis of Concentration Effects

Battaglia

Crea

et al. 2005

Annali di Chimica

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The protonation of polyacrylate (PAA, MW 2 kDa) was studied potentiometrically at 25 degrees C, in mixed electrolyte aqueous solution simulating the composition of seawater, in the salinity range 30 < or = S < or = 40. The salt composition of different solutions was varied in order to study its effect on apparent protonation constants. Results were analysed using two fairly different approaches: by simple regression analysis on a combination of concentration parameters and salinity, and by canonical correlation analysis. Unexpectedly we found that variations on protonation constants, due to the different relative component concentrations, are fairly low, revealing a sort of buffering capacity of seawater respect to protonation properties of polyacrylate (and likely for other HMW and LMW polycarboxylates). The intrinsic protonation constant of polyacrylate 2 kDa at 25 degrees C and 35 salinity is log K(H*) = log K(int) = 4.399 +/- 0.004. The use of different pH scales and standard seawater compositions is also discussed.

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“…Studies on the complexing ability of the inorganic content of sea water (as single salt BA) towards various acid-base systems, showed that the single salt approximation can be successfully applied(De Stefano et al 1998b). Hydrolysis constants of monomethyltin(IV) have been determined at different temperatures and the t1If values obtained are affected by large errors.…”

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confidence: 99%