A good buffer generally contains relatively equal concentrations of a weak acid and its conjugate base. Many different factors must be considered in choosing a good buffer, the most important being the ionic strength and the UV absorbance at low wavelength.
Additionally, the manner in which these buffers are prepared and how they are used in a particular application may strongly affect the speed and quality of a given separation. A weaker acid solution, HA, has a lower buffer strength to add a strong base.
Good buffers possess the following characteristics.
- Should have the high chemical stability
- Low cell membrane permeability
- Low metal chelating capacity
- Should have consistent acid-base dissociation constant
- Low absorption spectra in UV and visible regions