HPLC Buffer Salts
In case of high performance liquid chromatography (HPLC), it is very important to make the selection of the right buffer, as they are used in the mobile phase, and are responsible for holding the buffer constant. HPLC buffer salts are usually made up of a weak acid or weak base, in combination with their with their respective conjugate base/acid in the solution which is usually partially aqueous. The manner in which buffer salts work in the solution is that the aforesaid pair of compounds maintain an equilibrium of sorts, which is why on addition of an acid or a base, a shift in the equilibrium is observed to compensate the change in values, and thus, help in maintenance of a constant pH value.
1) They are commonly used during the analysis of ionizable components in the whole phasing and chromatographic process
2) It is advised that the pH of the buffer should always be at least two (2) values away from the pKa value of the analyte
3) Volatility of the buffer is another is another highly critical parameter which should be duly addressed and modifiers can also be used to keep the pH in check
4) Concentration should ideally be kept at the lowest value at which it can produce viable results as higher concentrations come with a risk of precipitation