| Autor: |
Roy RN; Hoffman Department of Chemistry, Drury University, 900 N. Benton Ave., Springfield, MO 65802, USA., Roy LN, Henson IB, Stegner JM, Dinga JJ, Summers CE, Suhrheinrich GL, Veliz JA, Dieterman LA |
| Jazyk: |
angličtina |
| Zdroj: |
The Journal of chemical thermodynamics [J Chem Thermodyn] 2012 Sep 01; Vol. 52, pp. 11-15. Date of Electronic Publication: 2012 Mar 05. |
| DOI: |
10.1016/j.jct.2012.02.019 |
| Abstrakt: |
The pH values of two buffer solutions without NaCl and seven buffer solutions with added NaCl, having ionic strengths (I = 0.16 mol·kg(-1)) similar to those of physiological fluids, have been evaluated at 12 temperatures from T = (278.15 to 328.15) K by way of the extended form of the Debye-Hückel equation of the Bates-Guggenheim convention. The residual liquid junction potentials (δE(j)) between the buffer solutions of TRICINE and saturated KCl solution of the calomel electrode at T = (298.15 and 310.15) K have been estimated by measurement with a flowing junction cell. For the buffer solutions with the molality of TRICINE (m(1)) = 0.06 mol·kg(-1), NaTRICINE (m(2)) = 0.02 mol·kg(-1), and NaCl (m(3)) = 0.14 mol·kg(-1), the pH values at 310.15 K obtained from the extended Debye-Hückel equation and the inclusion of the liquid junction correction are 7.342 and 7.342, respectively. These are in excellent agreement. The zwitterionic buffer TRICINE is recommended as a secondary pH standard in the region for clinical application. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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