Diurnal Fluctuations in the Hydrogen Ion Activity of a Minnesota Lake

Ecology ◽  
1927 ◽  
Vol 8 (1) ◽  
pp. 73-89 ◽  
Author(s):  
Cornelius B. Philip
Keyword(s):  
Hydrogen Ion ◽  
Ion Activity ◽  
Diurnal Fluctuations

scholarly journals THE INFLUENCE OF SALTS UPON THE IONISATION OF EGG ALBUMIN

1927 ◽  
Vol 8 (6) ◽  
pp. 543-599 ◽  
Author(s):  
S. P. L. Sørensen ◽  
K. Linderstrøm-Lang ◽  
Ellen Lund
Keyword(s):  
Experimental Determination ◽  
Ammonium Chloride ◽  
Salt Concentration ◽  
Hydrogen Ion ◽  
Hydrogen Ions ◽  
Egg Albumin ◽  
Ion Activity ◽  
The Mean ◽  
Acids And Bases

Introduction. A description is given of the principle followed in the experimental determination of the ionisation of egg albumin, its capacity to combine with acids and bases. Egg albumin is regarded as an ampholyte, and in accordance with J. N. Brønsted's definition of acids and bases, ampholytes are considered as substances capable of both taking up and giving off hydrogen ions. The theoretical treatment of the capacity of ampholytes to combine with acids (and bases) has been carried out on this basis. Section A. Several experimental series are noted, comprising the determination of the activity coefficient of the hydrogen ion (fH) in ammonium chloride solutions of different concentration. Section B. The general method of experimental determination of the ionisation (capacity to combine with adds and bases) of egg albumin in ammonium chloride and potassium chloride solutions is briefly described, and the results of the experiments are compared. Section C. 1). In a brief theoretical survey we have suggested that distinction should be made between isoelectric and isoionic reaction of an ampholyte, the former defined as the hydrogen ion activity (value of paH) at which the mean valency of the ampholyte is 0, the latter as the hydrogen ion activity at which the quantity of acid or base combined with the ampholyte is 0; or, as we prefer to express it, the hydrogen ion activity at which the specific hydrogen ionisation of the ampholyte is 0. If the ampholyte does not combine with other ions than the hydrogen ion, then isoelectric and isoionic reaction coincide. Isoionic reaction is determined by acid-combining experiments. The principle of this determination is briefly described. A theoretical investigation of the alteration with salt concentration of both isoelectric (isoionic) reaction and the shape and direction of the ionisation curves is made, with regard to ampholytes capable only of combining with hydrogen ions, on the basis of the Debye-Hückel formulæ and Linderstrøm-Lang's theory for the ionisation of polyvalent ampholytes of simple type. It is shown that the salt effect, in accordance with the theory, and in qualitative agreement with the experiments, consists in a turning of the ionisation curves, indicating the relation between the quantity of combined acid (specific hydrogen ionisation) and paH, and the turning of the curves, which leaves the isoelectric reaction unaltered, tends in such a direction that the quantity of combined acid at constant ampholyte concentration and constant pan increases with increasing salt concentration. The possibility of chemical combining of other ions than the hydrogen ion is discussed. 2). Following on 1), a brief survey of the experimental results is given. 3). The isoionic reaction is found from the experimental material and proved to be independent of the ammonium chloride concentration. As the mean of all determinations we have paH0 = 4.898 (isoionic reaction). The difference between this value and that formerly found for ammonium sulphate solutions (4.844) is discussed. 4). Finally, on the basis of the theory in Section 1), some simple calculations of the ionisation curves for egg albumin are made, and it appears that the theory can reproduce the experimental results in a rough quantitative way when we assume that the egg albumin has a radius of 2.21·10–7 cm. (answering to a molecular weight of 35,000 in aqueous solution), and contains 30 acid and base groups.

Use of Tris Buffers for Quality Control of Blood pH

1974 ◽  
Vol 20 (10) ◽  
pp. 1337-1340 ◽  
Author(s):  
Jack H Ladenson ◽  
Carl H Smith ◽  
David N Dietzler ◽  
J E Davis
Keyword(s):  
Quality Control ◽  
Control Program ◽  
Hydrogen Ion ◽  
National Bureau ◽  
Quality Control Program ◽  
Blood Ph ◽  
Relative Standard ◽  
Ion Activity ◽  
Primary Standards ◽  
Routine Quality Control

Abstract Tris(hydroxymethyl)aminomethane buffers have been established as sensitive and convenient indicators of the reliability of blood pH analysis. These buffers were compatible for routine use with blood-pH equipment from major manufacturers, except for two instruments. A seven-month study demonstrated the necessity of a routine quality-control program, as well as the need for systematic cleaning and maintenance of pH equipment. Tris(hydroxymethyl)aminomethane buffers were found not to be suitable as primary standards because we could not obtain the stated values with commercial pH equipment that had been standardized with phosphate buffers from the National Bureau of Standards. The relative standard deviation for measurement of hydrogen ion activity, 4.1% , indicates a need for improvement in the design and operation of equipment for the measurement of blood pH.

scholarly journals THE COMBINATION OF SALTS AND PROTEINS. I

1924 ◽  
Vol 7 (1) ◽  
pp. 25-38 ◽  
Author(s):  
John H. Northrop ◽  
M. Kunitz
Keyword(s):  
Surface Effect ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Complex Ions ◽  
Ion Distribution ◽  
Electrode Potentials ◽  
Ion Activity ◽  
Activity Ratios ◽  
The Difference ◽  
Total Concentrations

1. It has been found that the ratios of the total concentrations of Ca, Mg, K, Zn, inside and outside of gelatin particles do not agree with the ratios calculated according to Donnan's theory from the hydrogen ion activity ratios. 2. E.M.F. measurements of Zn and Cl electrode potentials in such a system show, however, that the ion activity ratios are correct, so that the discrepancy must be due to a decrease in the ion concentration by the formation of complex ions with the protein. 3. This has been confirmed in the case of Zn by Zn potential measurements in ZnCl2 solutions containing gelatin. It has been found that in 10 per cent gelatin containing 0.01 M ZnCl2 about 60 per cent of the Zn++ is combined with the gelatin. 4. If the activity ratios are correctly expressed by Donnan's equation, then the amount of any ion combined with a protein can be determined without E.M.F. measurements by determining its distribution in a proper system. If the activity ratio of the hydrogen ion and the activity of the other ion in the aqueous solution are known, then the activity and hence the concentration of the ion in the protein solution can be calculated. The difference between this and the total molar concentration of the ion in the protein represents the amount combined with the protein. 5. It has been shown that in the case of Zn the values obtained in this way agree quite closely with those determined by direct E.M.F. measurements. 6. The combination with Zn is rapidly and completely reversible and hence is probably not a surface effect. 7. Since the protein combines more with Zn than with Cl, the addition of ZnCl2 to isoelectric gelatin should give rise to an unequal ion distribution and hence to an increase in swelling, osmotic pressure, and viscosity. This has been found to be the case.

Prediction of hydrogen ion activity in the ZnSO4–Na2SO4–H2SO4–NaOH–H2O system at 25 °C

2003 ◽  
Vol 68 (1-3) ◽  
pp. 107-114 ◽  
Author(s):  
Man-Seung Lee ◽  
Choon-Ki Na ◽  
Jong-Gwan Ahn ◽  
Myung-Hoon Lee
Keyword(s):  
Hydrogen Ion ◽  
Ion Activity
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