The development of a chemically-modified mercury thin film electrode for electroanalysis

The purpose of this project was to develop a chemically-modified mercury thin film electrode (MTFE) for use in the determination of trace metais from aqueous solutions by anodic stripping voltammetry (ASV) in both quiescent and flowing solutions. The CME (chemically-modified electrode) consists of a non-conducting polymer, poly-N-ethyltyramine (p-NET), coated onto a glassy carbon substrate, which was used with dithiocarbamate (dtc) groups grafted onto the polymeric amine groups. The complexing capabilities of the dithiocarbamate groups were used to provide a substrate for the formation of a chemically deposited mercury thin film electrode (MTFE) via complexation of mercuric ions at these sites. These results are presented in chapter 4, along with a comparison of the modified MTFE with the conventional MTFE. The development and characterisation of the polymeric film itself is discussed in chapter 3. To enable the performance of the electrode for ASV to be characterised, a study was carried out on the conventional MTFE , in which some previously unreported features of this electrode became apparent. These results are discussed in chapter 2. Chapter 1 is devoted to a review of the current state of electroanalysis, with particular emphasis on both the current and potential electroanalytical applications of CMEs to anodic stripping voltammetry (ASV). This consists firstly of a study of electroanalysis based on conventional electrode materiais, with particular emphasis on ASV, and thence the scope and applications of CMEs to this field. Finally, to assist the characterisation of the (p-NET) modified MTFE, the application of this technology to a conducting polymer (polypyrrole) is discussed (chapter 5).