Acid-base extraction is typically used to separate organic compounds from each other based on their acid-base properties.
Generally, most organic compounds are neutral, and therefore more soluble in organic solvents than they are in water. However, if the organic compound becomes ionic, then it becomes more soluble in water. This is useful in extracting an organic acid or base compound from an organic phase to an aqueous phase.
An acid-base extraction can be used to extract carboxylic acids from the organic layer into the aqueous layer. Most organic carboxylic acids are insoluble or slightly soluble in water, but these compounds are highly soluble in dilute aqueous sodium hydroxide because the acid is deprotonated by the base producing the sodium carboxylate salt.
Acid-Base Extraction
