Citrate: Valence and Milliequivalent Considerations

Abstract

Objective:

To demonstrate that an understanding of the valence of citrate in solution, as well as the valence of citric acid and citrate salts in the solid state, is essential to correctly quantify these compounds by milliequivalent (mEq) unit.

Data Sources:

Problems are presented and based on information provided in package inserts for citric acid/citrate salt-containing products.

Data Synthesis:

The rationale of the valence of citrate in solution is presented and the dependence of this variable on pH is illustrated graphically. The valence of citric acid and citrate salts in the solid state is reviewed.

Conclusions:

The intricate nature of the valence of citrate in solution makes the quantification of citrate using the mEq unit impractical. Whenever citrate is quantified by the mEq unit, the specific citrate ion that is referred to in a composition table should be clearly stated.