electrochemical deposition of nanocomposite was performed using a behpajuh potentiostat model BHP 2061-c (isfahan,iran). the Pt-counter electrode and the Ag/AgCI reference electrode used in the electrochemical process were from Azar electrode co.(urmieh,iran). the SPME device was home-made it consisted of a 23-gauge,9.0-cm stainless steel spinal needle obtained from Dr.Japan co,(tokyo,japan) and housed in a 6.0-cm hollow cylinder of Al with two nuts and two pieces of rubber septum. a piece of stainless steel wire (type 302,17 cmx0.3 mm) passing through the septum acted as the SPME fiber. one end of the fiber was attached to a metal cap and 4 cm of the other end was coated with a thin film of PoPD-co-pot/MCNTs.the steel wire within the SPME device which acted as the working electrode was obtained from american orthodontics (WI,USA)