The commonest impurities are water, EtOH and acetic acid. These can be removed by washing with aqueous 5% Na₂CO₃, then with saturated aqueous CaCl₂ or NaCl, and drying with K₂CO₃, CaSO₄ or MgSO₄. More efficient drying is achieved if the solvent is further dried with P₂O₅, CaH₂ or molecular sieves before distn. CaO has also been used. Alternatively, ethanol can be converted to by refluxing with acetic anhydride (ca 1mL per 10mL of ester); the liquid is then fractionally distd, dried with K₂CO₃ and redistd. At last, you would obtain the pure Ethyl acetate (CAS NO. ).

Rapid purification: Distil, dry over K₂CO₃, distil again and store over 4A molecular sieves.