Development of voltametric and flow injection based method for determination of diethylstylbestrol and propranol

In the first part of the thesis, the electrochemical determination of diethylstilbestrol (DES), one of the endocrine system disruptor chemicals, was carried out by two different methods. First, a voltammetric method was designed for the determination of DES with a modified electrode prepared by reducing gold on the pencil graphite electrode (PGE) surface. The modified electrode was characterized by cyclic voltammetry (CV), scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). The determination of DES was also investigated by a flow injection analysis system (FIA) with amperometric detection (AD). Thanks to including C18 columns in the FIA-AD system, the performance of the system was increased and this system was used for the first time for the determination of DES. As a result of the analysis, recovery in the range of 89.01-102.9% was obtained for milk, milk powder and water real samples. In the second part of the thesis, modified electrode was prepared by applying electrochemical pretreatment (ET) to the PGE and the prepared modified electrode (ET/PGE) was used in the electrochemical determination of Propranolol (PROP) that is a β-blocker. In the first step, the ET/PGE was characterized and the PROP was determined voltammetrically. In the second step, PROP was determined in FIA-AD and FIA-AD+C18 systems. As a result of real sample studies in the FIA-AD+C18 system, recovery in the range of 101.256- 108.04% in the pharmaceutical tablet and 98.8% -100.46% in the synthetic urine sample was obtained Keywords: Diethylstilbestrol, Propranolol, Gold nanoparticle, Flow injection analysis, Amperometric detection