Abstract
ThepK 2 values for 3-[(l,l-Dimethyl-2-hydroxymethyl)amino]-2-hydroxypropanesulfonic acid (AMPSO), and 3-[N,N-Bis(-hydroxyethyl)amino]-2-hydroxypropanesulfonic acid (DIPSO) have been determined at 12 temperatures over the range 5 to 55‡C by measurements of the emf of cells without liquid junction containing hydrogen and silver-silver chloride electrodes. The values of pK 2 for AMPSO and DIPSO were found to be 9.138 and 7.576, respectively, at 25‡C. The thermodynamic quantities, δG‡, δH‡, δS‡, and δC ‡p were calculated from the change of the equilibrium constants with temperature. These buffer substances are useful as secondary pH standards in the physiological region of pH 7 to 9.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
R. N. Roy, J. J. Gibbons, J. L. Padron, K. Buechter, and S. Faszholz, inAdvances in Chemistry Series, No. 177, W. F. Furter ed., (Amer. Chem. Soc.) Washington D.C. 1979, Chap. 18.
R. N. Roy, J. J. Gibbons, C. Krueger, and G. LaCross, Jr.,J. Chem. Thermodyn. 9, 325 (1977).
R. N. Roy, D. M. Mrad, Pamela J. Lord, J. A. Carlsten, William S. Good, Lakshmi N. Roy, and Kathleen M. Kuhler, submitted, Anal. Chem.
F. J. King,J. Amer. Chem. Soc. 75, 2204 (1953).
N. E. Good, G. D. Winget, W. Winter, T. N. Connolly, S. Izowa, and R. M. M. Singh,Biochem 5, 467 (1966).
W. J. Ferguson, K. I. Braunschweiger, W. R. Braunschweiger, J. R. Smith, J. J. McCormick, C. C. Wasman, N. P. Jarvis, D. H. Bell, and N. E. Good,Anal. Biochem. 104, 300 (1980).
R. N. Roy, R. A. Robinson, and R. G. Bates,J. Amer. Chem. Soc. 95, 823 (1973).
C. A. Vega, and R. G. Bates,Anal. Chem. 48, 1293 (1976).
R. Gary, R. G. Bates, and R. A. Robinson,J. Phys. Chem. 68, 1187 (1964).
R. G. Bates, Determination of pH, 2nd. edn. (Wiley, New York, 1973), Chapter 10.
R. N. Roy, C. P. Moore, M. N. White, L. N. Roy, K. M. Vogel, D. A. Johnson, and F. J. Millero,J. Phys. Chem 96, 403 (1992).
R. N. Roy, E. E. Swensson, G. LaCross, and C. W. Krueger,Anal. Chem. 477, 1407 (1975).
D. Feng, W. F. Kock, and Y. C. Wu,Anal. Chem. 61, 1400 (1989).
R. N. Roy, C. P. Moore, J. A. Carlsten, J. A. Niederschmidt, W. S. Good, L. N. Roy, and K. M. Kuhler,Analyt. Chemica. Acta, submitted.
D. J. G. Ives, and P. G. N. Moseley,J. Chem. Soc, Faraday Trans. 1, 72, 1132 (1976).
N. W. Please,Biochem. J. 56, 196 (1954).
B. A. Timimi, and D. H. Everett,J. Chem. Soc. Sec. B 1380 (1968).
R. N. Roy, L. N. Roy, J. A. Carlsten, J. A. Niederschmidt, W. S. Good, and K. M. Kuhler, Clinical Chemistry, in preparation.
Author information
Authors and Affiliations
Additional information
Camille and Henry Dreyfus Fellow, 1994–1996.
Rights and permissions
About this article
Cite this article
Roy, R.N., Carlsten, J.A., Niederschmidt, J. et al. Buffers for the physiological pH range: Thermodynamic constants of substituted aminopropanesulfonic acids from 5 to 55°C. J Solution Chem 26, 309–317 (1997). https://doi.org/10.1007/BF02768001
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF02768001