IMPROVEMENT OF SELECTIVITY OF ELECTROCHEMICAL DETECTION FOR THE DETERMINATION OF COMPOUNDS WITH CHLORO AROMATIC RINGS

Pharmaceuticals containing a thiazide ring or chlorinated aromatic rin g were investigated with respect to enhanced selectivity in determinat ion. Oxidative electrochemical detection coupled with HPLC was used to study the influence of the pH of the mobile phase under conditions of photolysis. To cover a pH range 3.9-12, the employment of a polymer c olumn stable in alkaline media was necessary. The method offers the gr eat advantage of derivatization without chemicals at low operating pot entials, thereby providing high selectivity.