الفهرس 
Aim of the workOnly 14 pages are availabe for public view
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Abstract
In this work, three sensitive, simple and rapid methods of quantitative analysis were developed, and they are as follows:
1- Square-wave adsorptive anodic stripping voltammetry onto the surface of the graphite reinforcement carbon paste electrode (GRCPE) electrochemically modified with 8-HQwhich converted to quinolyl radical and then formed complex with copper ions. The validity of the method was also verified for the determination of copper ions in different water samples.
2- Differential-pulse adsorptive anodic stripping voltammetry onto the surface of the GRCPE modified with MSK-NPs which formed physically bonded nanoparticles network with cadmium ions. The validity of the method was also verified for the determination of cadmium ions in Egyptian white rice and chocolate samples.
3- Square-wave adsorptive anodic stripping voltammetry onto the surface of the GRCPE modified with polyethylene glycol magnetic nanoparticles (PEG-MNPs) which physically bonded to a drug used in hypertension treatment namely PER.L-Arg. The validity of the method was also verified for the determination of PER.L-Arg in its pharmaceutical formulation and biological fluids such as; urine and blood serum samples.
The thesis falls into three main chapters
Chapter I:
This chapter includes general introductory information about voltammetric techniques as electrochemical analyzers, basic theory of voltammetry, general types of voltammetry, mass transport in electrochemical cells, working electrodes, copper, cadmium and PER.L-Arg. A review of the different methods that contributed to the determination of our target analytes that published in recent scientific journals was also included.
Chapter II:
This chapter includes the laboratory experimental information about the instruments, materials, solutions, water samples, food stuff, pharmaceutical formulation, biological fluids and procedures used in this thesis.
Chapter III:
This chapter is concerned with development of three direct, rapid, accurate, sensitive and easy methods for determination of Cu(II), Cd(II), and PER.L-Arg. This chapter comprises into three sections:
The first section:
Includes the results and discussion of the adsorption behavior of Cu(II) which explored onto the Q/GRCPE by square-wave and cyclic voltammetry, the performance of the electrochemically modified sensor was systematically studied.
The experimental data suggested that the electrochemically modified sensor exhibited excellent enhancement for the electrochemical oxidation of Cu(II) with a detection limit (LOD) 2.1×10-11M. The application of the electrochemically modified sensor for the detection of Cu(II) in Tap water (TW), ground water (GW) and Nile River water (NRW) showed good recovery with reproducible results. The peak currents of Cu(II) were evaluated within a wide concentration range, in favor of more durability, sensitivity, and selectivity which suitable for investigation of real samples. It was shown that the proposed electrochemically modified electrode proved to be a cheap ”pre- alarm” tool for rapid determination of Cu(II) in environmental water samples even in the presence of some interfering ions. The adsorptive accumulation of Cu(8-HQ)2, approaches results in an effective preconcentration of Cu(II) with short adsorption time (30s).
The second section:
Includes the results and discussion of the adsorption behavior of Cd(II) onto MSK-NPs/GRCPE which explored by differential-pulse and cyclic voltammetry, the performance of the modified sensor was systematically examined.
The experimental data suggested that the modified sensor exhibited excellent response for the Cd(II) with a detection limit (LOD) 5.435×10-9M. The application of the modified sensor for the determination of Cd(II) in chocolate and Egyptian white rice showed good recovery with reproducible results. The current response of Cd(II) was evaluated within a wide concentration range, in favor of more durability, sensitivity, and selectivity which suitable for examination of real samples. It was shown that the proposed modified MSK-NPs/GRCPE proved to be a reliable, cheap and environment friendly tool for the monitoring of Cd(II) in chocolate and rice samples even in the presence of some interfering ions. The functional groups that present on the surface of MSK-NPs, approaches results in an effective preconcentration of Cd(II) with short adsorption time (30 s).
The third section:
Includes the results and discussion of the adsorption behavior of PER.L-Arg onto PEG-MNPs/GRCPE which explored by square-wave and cyclic voltammetry. The developed magneto electrochemical sensor, PEG-MNPs/GRCPE, was successfully applied in the accurate detection of PER.L-Arg in pharmaceutical dose and biological with a detection limit (LOD) 3.616 ×10-10M. . The current response of PER.L-Arg was evaluated within a wide concentration range, in favor of more durability, sensitivity, and selectivity which suitable for examination of real samples. It was shown that using of PEG-MNPs as fixed functionalized magnetic beads made the oxidation of all amounts of the target molecules a guaranteed process.