In this work the electrochemical behavior of substances of environmental concern [bentazone,atrazine, carbamazepine, phenytoinanditsmetabolite5-(4-hydroxyphenyl)-5-phenylhydantoin,HPPH] on a glassy carbon working electrode (Ag/AgClreferenceelectrode) was studied with the aim to develop a HPLC method coupled with amperometric detection. Constant potential (DC), pulsed amperometric detection modes were studied. For the pulsed mode, several waveforms were set and investigated. Detection conditions were optimized as a function of eluent pH.