Studies of the Zwitterionic Buffer for the Biological pH Range: 2-hydroxy-3-[[2-hydroxy 1,1bis(hydroxymethyl) ethyl]amino]-1-propane sulfonic Acid (TAPSO) from (278.15 to 328.15)K|Chapter 1 | Current Research Progress in Physical Science Vol. 8

The present study highlights buffer standards for the physiological pH of the zwitterionic buffer 2-hydroxy-3-[[2-hydroxy-1, 1-bis (hydroxymethyl)ethyl)] amino]-1-propanesulfonic acid (TAPSO) from 278.15 to 325.15 K. The values of the second dissociation constant, pK₂, and related thermodynamic quantities of (TAPSO) have already been reported at 12 temperatures over the temperature range 5 to 50^oC, including 37^oC (body temperature) from this laboratory (Roy et al., 1997). Now this paper reports the results of the conventional paH for five buffer solutions without the chloride ion and also five buffer solutions with NaCl at ionic strength (I = 0.16 mol.kg^-1) similar to blood plasma and other physiological fluids in the temperature range 278.15 to 325.15 K. Electromotive force (emf) measurements and the extended Debye-Hückel equation have been used for the calculation of the values (designated as paH). The operational pH values for five buffer solutions at 278.15 K and 325.15 K have been calculated using the values of the residual liquid function potential (δEj) between the TAPSO buffer solutions and the blood phosphate primary buffer standard. The values of the δEj of these buffer solutions were obtained using the saturated KCl calomel electrode of the flowing junction cell. These three zwitterionic buffer solutions of TAPSO are recommended as primary pH standard reference solutions for pH measurements of the saline media (I = 0.16 mol kg-1), the clinical fluids such as blood serum. The results will be widely used in biochemical assays and pharmaceutical sciences.  The consistency of three sets of experimental data listed in Table 9 leads credibility in the pH values of these TAPSO buffer solutions.

 

Author (s) Details

 

Lakshmi N. Roy
Hoffman Department of Chemistry, Drury University, Springfield, USA.

 

Rabindra N. Roy
Hoffman Department of Chemistry, Drury University, Springfield, USA.

 

Blake M. Bodendorfer
Hoffman Department of Chemistry, Drury University, Springfield, USA.

 

Zachary M. Downs
Hoffman Department of Chemistry, Drury University, Springfield, USA.

 

Stephen D. Rocchio
Hoffman Department of Chemistry, Drury University, Springfield, USA.

 

Jessica M. Stegner
Hoffman Department of Chemistry, Drury University, Springfield, USA.

 

Isaac B. Henson
Hoffman Department of Chemistry, Drury University, Springfield, USA.

 

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Determining Thermodynamics of the Second Dissociation Constants of Protonated Piperazine-N, N′-bis-2-Hydroxypropane-Sulfonic Acid POPSO at Different Temperatures from 278.15 to 328.15 K | Chapter 1 | Chemistry and Biochemistry: Research Progress Vol. 1

The second acidic dissociation constants of protonated piperazine-N, N′-bis-2-hydroxypropane-sulfonic acid (POPSO sesquisodium salt) have been determined at 12 different temperatures (from 278.15 to 328.15) K including 310.15 K. Electromotive-force measurement technique was used employing hydrogen-silver chloride cells without liquid junction. The results of pK₂ are given by the equation: pK2 = -1041.77/T + 51.0459 - 6.97646lnT. The uncertainty of the fit is ±0.0008. At 289.15 K, pK₂ = 7.8029; whereas, at 310.15 K (body temperature), pK2 = 7.6862. Thus, the buffer solutions of POPSO and its sodium salt are useful for pH control in the physiological pH region of (7.0 to 8.5). The changes of Gibbs free energy (∆G°), enthalpy (∆H°), entropy (∆S°) and heat capacity ∆Cp° were computed from the temperature derivative of the pK2 for the dissociation of the zwitterionic acid POPSO±^-3 = POPSO^-4 + H⁺ in the standard state. At 298.15 K, these results are compared with those of similar components, which are the derivatives of the parent compounds TAURINE, PIPERAZINE and MORPHOLINE.

These results (slight increase in ∆Cp° of POPSO) suggest that the substitution and the presence of an extra monosodium POPSO molecule in POPSO disodium salt apparently have two effects: 1) progressive increase of hydrophobic characters (tending to increase ∆Cp°), and 2) some changes in the solvation pattern, that is, progressively greater steric hindrance (tending to increase ∆Cp° value by exclusion of solvent).

 

Author (s) Details

 

Rabindra N. Roy
Hoffman Department of Chemistry, Drury University, Springfield, MO, USA.

 

Lakshmi N. Roy
Hoffman Department of Chemistry, Drury University, Springfield, MO, USA.

 

Katherine E. Hundley
Hoffman Department of Chemistry, Drury University, Springfield, MO, USA.

 

Taylor R. Wehmeyer
Hoffman Department of Chemistry, Drury University, Springfield, MO, USA.

 

Lucas S. Tebbe
Hoffman Department of Chemistry, Drury University, Springfield, MO, USA.

 

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Examining and Calculating the pH of 2-[N-Morpholino]ethanesulfonic Acid (MES) Buffer Solution from 5˚C to 55˚C | Chapter 1 | Chemical and Materials Sciences: Developments and Innovations Vol. 10

In biomedical, biological, and clinical laboratories, knowledge of the pH of blood and physiological fluids is of great importance. This paper reports the results for the pH of three buffer solutions free of chloride ions. The remaining six buffer solutions have saline media of ionic strength I=0.16 mol⋅ kg^-1 matching closely to that of the physiological sample. Conventional pa_H values for the three buffer solutions without the chloride ion and six buffer solutions with the chloride ion at I=0.16 mol⋅ kg-1 from 5^∘ C to 55^∘ C have been calculated. The operational pH values for five buffer solutions at 5∘ C to 55∘C have been determined based on the difference in the values of the liquid junction potentials between the blood phosphate standard and the experimental buffer solutions. Five of these buffers are recommended as standards for the physiological pH range of 7.5 to 8.5. It was concluded that all emf data are stable, reliable, and accurate. The MES buffer solutions are considered standards of assigned pH and will be useful when buffer solutions of known conventional pH are required.

 

Author (s) Details

Lakshmi N. Roy
Hoffman Department Of Chemistry, Drury University, Springfield, Usa.

 

Rabindra N. Roy
Hoffman Department Of Chemistry, Drury University, Springfield, Usa.

 

Joshua T. Wollen
Hoffman Department Of Chemistry, Drury University, Springfield, Usa.

 

Jessica M. Stegner
Hoffman Department Of Chemistry, Drury University, Springfield, Usa.

 

Meagan A. Harmon
Hoffman Department Of Chemistry, Drury University, Springfield, Usa.

 

Michael S. Martin
Hoffman Department Of Chemistry, Drury University, Springfield, Usa.

 

Blake M. Bodendorfer
Hoffman Department Of Chemistry, Drury University, Springfield, Usa.

 

Isaac B. Henson
Hoffman Department Of Chemistry, Drury University, Springfield, Usa.

 

Please See The Book Here:- Https://Doi.Org/10.9734/Bpi/Cmsdi/V10/3473