Psychoanalytic Analysis

In this part of the chapter the experimental techniques, instrumentation and basic equipment necessary for electrochemistry like a potentiostat, a recording device and an electrochemical cell. The electrode system with special emphasis on carbon paste electrodes used in the course of this research is outlined. Preparation of carbon paste electrodes and Modified electrodes by electropolymerization, pre-treatment and immobilization of surfactants film modified carbon paste electrodes surfaces, and procedures used in the present work are detailed. In addition, an overview of the theories characterization techniques and related equations are described.

2.2. Experimental Techniques

The chief electrochemical / analytical techniques used throughout

With the help of this method, it is possible to get information about the type of reactions observed in the system like thermodynamics of redox processes, kinetics of heterogeneous electron-transfer reactions, and on coupled chemical reactions or adsorption processes. Cyclic voltammetry is often the first experiment performed in an electroanalytical study. In particular, it offers a rapid location of redox potentials of the electro active species, and convenient evaluation of the effect of media upon the redox process [1-2]. Cyclic voltammetry is an technique where the potential applied at the working electrode is swept between two chosen potential limits and the change in current is monitored. This is done at a constant rate known as the scan rate. The initial applied potential, Ei, is swept to a vertex potential, Ev, where the scan is reversed and swept back to the final potential, Ef, which usually equals the original potential, Ei. This process creates a cyclic effect and is typically repeated a number of times. Cyclic voltammetry was primarily used to in the study of the electrochemical behavior of the polymer film modified carbon paste electrode towards the oxidation and reduction of dopamine (DA). It was also used to investigate the effect of numerous

Potentiostat

Poteniostat is one the device it is widely used in the electrochemical studies and makes possible the performance of techniques such as cyclic voltammetry.The main principal of poteniostat to control potential and the measured current visa versa. The conventional three-electrode potentiostat is connected to the working, reference and auxiliary electrodes immersed in the test solution placed in the cell. It controls the potential of the working electrode (WE), with respect to the reference electrode (RE) while simultaneously measuring the current flowing between the WE and the auxiliary electrode (AE) (Fig 2.1). The potentiostat performs three functions:

i. Controls the applied potential, which is potential difference between the WE and RE (the applied potential controls what half reactions occur at the WE); ii. Allows to pass current between the WE and AE without passing current through the RE (which would change its potential if current did pass through it) and iii. Converts the cell current to a voltage for recording devices.

2.3.1.1. Potentiostat Employed in the Present Work for CV and DPV