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Buffer capacity rises to a local maximum at pH = pK a. The height of this peak depends on the value of pK a. Buffer capacity is negligible when the concentration [HA] of buffering agent is very small and increases with increasing concentration of the buffering agent. [3] Some authors show only this region in graphs of buffer capacity. [2]
HEPES (4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid) is a zwitterionic sulfonic acid buffering agent.It is one of the twenty Good's buffers.HEPES is widely used in cell culture, largely because it is better at maintaining physiological pH despite changes in carbon dioxide concentration (produced by aerobic respiration) when compared to bicarbonate buffers, which are also commonly used in ...
Within a rock of a given chemical composition, iron enters minerals based on the bulk chemical composition and the mineral phases which are stable at that temperature and pressure. For instance, at redox conditions more oxidizing than the MH (magnetite-hematite) buffer, at least much of the iron is likely to be present as Fe 3+ and hematite is ...
The following table presents pK a values at 20 °C. Values change by about 0.01 per degree of temperature. [1] [3] Good's original 1966 paper had two older buffers (marked with italics) for comparison. In 1972 Good published a second list with three more buffers, and five more were added in 1980.
Buffer solutions also play a key role in analytical chemistry. They are used whenever there is a need to fix the pH of a solution at a particular value. Compared with an aqueous solution, the pH of a buffer solution is relatively insensitive to the addition of a small amount of strong acid or strong base.
Desalting and buffer exchange are two of the most common gel filtration chromatography applications, and they can be performed using the same resin. Desalting and buffer exchange both entail recovering the components of a sample in whatever buffer is used to pre-equilibrate the small, porous polymer beads (resin).
In chemistry and biochemistry, the Henderson–Hasselbalch equation = + ([] []) relates the pH of a chemical solution of a weak acid to the numerical value of the acid dissociation constant, K a, of acid and the ratio of the concentrations, [] [] of the acid and its conjugate base in an equilibrium.
Tricine is an organic compound that is used in buffer solutions. The name tricine comes from tris and glycine, from which it was derived. [1] It is a white crystalline powder that is moderately soluble in water. It is a zwitterionic amino acid that has a pKa1 value of 2.3 at 25 °C, while its pKa2 at 20 °C is 8.15. Its useful buffering range ...