Buffer Standards for the Physiological pH of the Zwitterionic Compound, ACES, from 5 to 55 deg C
The values of the second dissociation constant, pK 2, and related thermodynamic quantities of [N-(2-acetamido)-2-aminoethanesulfonic acid] (ACES) have already been reported over the temperature range 5 to 55 deg C including 37 deg C. This paper reports the pa H values of four chloride ion free buffe...
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Published in | Journal of solution chemistry Vol. 38; no. 4; pp. 471 - 483 |
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Main Authors | , , , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
01.04.2009
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Online Access | Get full text |
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Summary: | The values of the second dissociation constant, pK 2, and related thermodynamic quantities of [N-(2-acetamido)-2-aminoethanesulfonic acid] (ACES) have already been reported over the temperature range 5 to 55 deg C including 37 deg C. This paper reports the pa H values of four chloride ion free buffer solutions and eight buffer solutions with I=0.16 mol.kg, matching closely that of the physiological sample. Conventional pa H values for all twelve buffer solutions from 5 to 55 deg C are reported. The residual liquid-junction potential correction for two widely used temperatures, 25 and 37 deg C, has been made. The flowing-junction calomel cell method has been utilized to measure E j, the liquid-junction potential. The operational pH values for four buffer solutions at 25 and 37 deg C are calculated using the physiological phosphate buffer standard based on the NBS/NIST convention. These solutions are recommended as pH standards in the pH range of 6.8 to 7.2 for physiological fluids. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 content type line 23 ObjectType-Feature-1 |
ISSN: | 0095-9782 1572-8927 |
DOI: | 10.1007/s10953-009-9380-9 |