a substance that, by its presence in solution, increases the amount of acid or alkali necessary to produce a unit change in pH.
isohydric buffer1 systems
all of the buffer systems in the extracellular fluid act in unison so that when e.g. extra acid is added all of the buffer systems will buffer some of the additional hydrogen ions. This is the isohydric principle and the buffer systems involved are the isohydric buffers.
the pairs of compounds which, in themselves, serve as a buffer system. There are a number of such pairs in the blood and the sum of the blood's buffering capacity is the sum of these individual pairs.
a chemical constituent of developer and fixer to keep the pH constant.
see buffer salt.
a system consists of a weak acid and a conjugate base, e.g. a mixture of carbonic acid and bicarbonate ions. When one is present the addition of more acid or base will raise or lower the pH much less than if no buffer were present. The principal buffer systems are the bicarbonate, plasma protein, phosphate and hemoglobin buffers. See also henderson-hasselbalch equation.
buffer1 titration curve
mathematical calculations used to predict buffering capacity and bicarbonate concentration under various values of carbon dioxide tension.