HPLC Separation of Toluidine Isomers

Toluidine isomers are based on toluene and differ whether the primary amine is ortho, meta or para to the methyl group. A Primesep 200 column with an ammonium formate buffer or a Primesep 100 column with sodium phosphate baseline resolves the three regioisomers. The HPLC separation uses a mobile phase of water, acetonitrile (MeCN, ACN), ammonium formate, or sodium phosphate and ultraviolet (UV) detection at 250 nm.