Acid–Base Partition Cleanup
Acid–base partition cleanup is a liquid–liquid extraction procedure  for the separation of acid analytes, such as organic acids and phenols from base/neutral analytes (amines, aromatic hydrocarbons, halogenated organiccompounds) using pH adjustment. This method is used for the cleanup of petroleum waste prior to analysis or further cleanup. The extract fromthe prior solvent extraction is shaken with water that is strongly basic. Thebasic and neutral components stay in the organic solvent, whereas the acid
analytes partition into the aqueous phase. The organic phase is con centratedand is ready for further cleanup or analysis. The aqueous phase is aci dified and extracted with an organic solvent, which is then concentrated (ifneeded) and is ready for analysis of the acid analytes (Figure 1.1).

Figure 1.1.Acid–base partition cleanup