Mixed component phases phosphorates

In all cements used in dentistry the hardening process is based on an acid-base reaction. The cementing mix is obtained by mixing a powder of the basie eomponent with a liquid phase containing the acid component. The basic component may be a metal oxide, such as ZnO or MgO, a calcium silicate, or a glass phase able to release free ions into the solution. The liquid phase consists of monomers, or more often polymers of a carboxylic acid or phosphoric acid. 

As described earlier, a mobile phase is the liquid that is pumped through die column. Mobile phases are comprised of major and minor components. In RP sqiarations, components are typically considered major if they are present at levels of >5% in the mobile phase. Mmor components are present at <5% and are commonly referred to as mobile phase modifiers, lypical mobile phase modifiers (MPMs) are undiluted acids (e.g., phosphoric, trifluoroacetic, and acetic) and bases (e.g., trietlqrlamine, triethanolamine, and diethylamine) as well as buffer systems (e.g., phosphate and acetate or mixed such as trifluoroacetic acid/triethylamine) and ion-pair reagents (e.g., sodium dodecyl sul te and tetrabutylammonhun phosphate). 

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