6533b7d8fe1ef96bd126a519
RESEARCH PRODUCT
Modeling ATP protonation and activity coefficients in NaClaq and KClaq by SIT and Pitzer equations.
Demetrio MileaAlberto PettignanoSilvio SammartanoConcetta De Stefanosubject
Activity coefficientMolar concentrationactivity coefficientsActivity coefficientPotentiometric titrationInorganic chemistryBiophysicsIonic bondingProtonationProtonationATP; protonation; activity coefficients; Dependence on medium and ionic strength; SIT model; Pitzer modelSodium ChlorideBiochemistryPotassium ChlorideAdenosine TriphosphateElectrochemistrySettore CHIM/01 - Chimica AnaliticaChemistryOrganic ChemistryOsmolar ConcentrationPitzer modelSIT modelATPSpecific ion interaction theoryIonic strengthDependence on medium and ionic strengthPhysical chemistryPitzer equationsdescription
Abstract The acid–base properties of Adenosine 5′-triphosphate (ATP) in NaCl and KCl aqueous solutions at different ionic strengths (0 I / mol L − 1 ≤ 5 for NaCl aq , 0 I / mol L − 1 ≤ 3 for KCl aq ) and at t = 25 °C were investigated. A selection of literature data on ATP protonation constants and on activity isopiestic coefficients was performed, together with new potentiometric measurements (by ISE-H + , glass electrode). Both literature and new experimental data were used to model the dependence on ionic strength and ionic medium of ATP protonation by SIT (Specific ion Interaction Theory) and Pitzer equations. In addition to values of first and second ATP protonation constants in NaCl aq and KCl aq at different ionic strengths, stability constants of NaATP 3− and KATP 3− complexes, SIT interaction coefficients and Pitzer parameters were calculated, together with protonation constants at infinite dilution: log T K 1 H = p T K a2 = 7.656 ± 0.010 and log T K 2 H = p T K a1 = 4.561 ± 0.006 (in the molar concentration scale, ± 95% confidence interval). Both SIT and Pitzer approaches give satisfactory results.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2006-01-01 | Biophysical chemistry |