Mean hydrogenion concentration: A valuable parameter in 24-hour esophageal monitoring?

1998 ◽  
Vol 114 ◽  
pp. A243
Author(s):  
E.C. Niemantsverdriet ◽  
R. Timmer ◽  
R. Breumelhof ◽  
A.J.P.M. Smout
Keyword(s):  
Hydrogenion Concentration

200. The colorimetric determination of pH in milk and whey by means of the “Wulff” pH tester

1938 ◽  
Vol 9 (3) ◽  
pp. 336-338 ◽  
Author(s):  
E. Aschaffenburg
Keyword(s):  
Colorimetric Method ◽  
Cheddar Cheese ◽  
Titratable Acidity ◽  
Colorimetric Determination ◽  
Expensive Equipment ◽  
Hydrogenion Concentration ◽  
The Relationship

It has been repeatedly pointed out(1, 2, 3) that the properties of cheese during the different stages of its manufacture should be correlated with the hydrogenion concentration rather than with the titratable acidity. Little systematic work has, however, so far been carried out in this direction, except for a study of the relationship between pH and titratable acidity in Cheddar cheese by Brown & Price(4). In planning work on similar lines, it was realized that the potentiometric methods of determining pH require expensive equipment and skilled attention, so that a supplementary colorimetric method, if sufficiently accurate to indicate the major changes in pH, should appeal more strongly to the practical cheesemaker on account of its cheapness and simplicity and the ease with which the outfit can be transported.

Studies on soil reaction: III. The determination of the hydrogenion concentration of soil suspensions by means of the hydrogen electrode

1925 ◽  
Vol 15 (2) ◽  
pp. 201-221 ◽  
Author(s):  
Edward M. Crowther
Keyword(s):  
Dilution Effect ◽  
Ion Concentration ◽  
Soil Reaction ◽  
Neutral Salt ◽  
Alkaline Soils ◽  
Hydrogen Electrode ◽  
Hydrogen Ion Concentration ◽  
Base Exchange ◽  
Buffer Action ◽  
Hydrogenion Concentration

A hydrogen electrode apparatus for soils is described. Similar or adjacent soils may show considerable differences inpH value, with no changes in their degrees of buffer action, as shown in titration curves with lime water. In such cases the conventional “lime requirements” are correlated with thepH values, but no such relation holds in dissimilar soils. ThepH value of a soil suspension is intimately connected with the nature and amount of the cations present. Neutral salts markedly increase the hydrogen ion concentration of both acid and slightly alkaline soils. Sodium salts, including the hydroxide, give lower hydrogenion concentrations than the corresponding potassium or calcium salts, and chlorides give lowerpH values than sulphates. The degree of buffer action (slope of titration curve) is unaffected by the addition of a neutral salt. Previous extraction of a soil with water causes a considerable increase i n thepH value of its suspensions. A number of soils showed a regular increase of about 0·1 inpH. value for twofold dilution. The “salt effect” and “dilution” effect appear to be of the same type. It is recommended that the soil-water ratio of 1:5 be generally adopted. The indicator methyl red gives erroneouspH values in turbid soil suspensions owing to the absorption of the red form, which is apparently a cation capable of undergoing “base exchange” with the soil.

scholarly journals On the Use of Sodium Bicarbonate and Calcium in the Rectification of Sea-Water in Aquaria

1932 ◽  
Vol 18 (1) ◽  
pp. 199-200 ◽  
Author(s):  
C. M. Breder ◽  
H. W. Smith
Keyword(s):  
Sodium Bicarbonate ◽  
Sea Water ◽  
Calcium Content ◽  
Closed Circulation ◽  
Hydrogenion Concentration

The use of sodium bicarbonate for the maintenance of the proper hydrogenion concentration and bicarbonate content in marine aquaria using a closed circulation, was recommended by Breder and Howley (1). It was pointed out by them that this substance was more suitable for such purposes than quicklime which is used in the Plymouth Aquarium, because the latter “disproportionately increases the calcium content.” Atkins (2) disagrees with this opinion chiefly on the grounds that sulphates from metabolized food do not tend to increase the acidity of the water. Atkins quotes Smith (3) as stating that the urinary SO4 comes from ingested sea-water, and neglects entirely the fact that Smith had reference to the bulk of the urinary salts. As Smith remarks on page 494, a fraction of the urinary S04 is of metabolic origin, and this fraction is of course the only S04 which is significant in the problem discussed by Breder and Howley.

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