الفهرس 
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Abstract
Summary and Conclusion
The present study aims to determination of some pesticides (deltamethrin and dimmethoate) in pure forms, formulations and environmental and biological samples by the proposed simple, rapid, accurate, and sensitive spectrophotometric methods using two different techniques (oxidation reduction and condensation).
The present thesis contains four chapters:
Chapter I:
Include introduction about the importance of the pesticides analysis, the specifications of the analytical methods used in pesticides determination, the requirements of the validation of these methods (sensitivity of spectrophotometric methods; precision and accuracy; detection and quantification limit and comparison of the results). Also an introduction about the pesticides and reagents under consideration (The definitions, actions, chemical structures and chemical names).
Chapter II:
Gives a literature survey of the previous studies for the analysis of the studied pesticides and reagents including spectrophotometry, chromatography, electroanalytical and other methods.
Chapter III:
Contains the experimental part, which includes apparatus used for measurement, chemicals and procedures for the preparation of pesticides and reagents solutions. It also contains in detailed explanation about the proposed spectrophotometric methods for determination of the studied pesticides in pure forms, formulations and environmental and biological samples.
Chapter IV:
Contains the results and discussion which include two parts, each part includes a procedure for determination of the pesticides under investigation using the different techniques (oxidation reduction and condensation):
1.a. Sensitive spectrophotometric methods for the determination of some pesticides using Ce(IV) ammonium sulfate and two dyes
In this investigation, we investigate the development of indirect redox spectrophotometric reaction for determination deltamethrin and dimethoate
with Ce(IV) ammonium sulfate in acid medium, followed by determination of unreacted Ce(IV) by reacting it with a fixed amount of amaranth and measuring the absorbance at 520 nm (method A), rhodamine 6G at 525 nm (method B). In all methods, the amount of Ce(IV) reacted corresponds to the amount of pesticide and the measured absorbance is found to increase linearly with the concentration of pesticide with correlation coefficients of 0.9993- 0.9997. The Beer’s law is obeyed in the concentration ranges 0.5-4.5 and 0.5-6.0 μg mL-1(method A) and ranges
0.5-4 and 0.5-5.0 μg mL-1 (method B) for deltamethrin and dimethoat, respectively .
1.b. Sensitive spectrophotometric methods for the determination of some pesticides using N-bromosuccinimide and two dyes
In this investigation, we investigate the development of indirect redox spectrophotometric reaction for determination of deltamethrin or dimethoate with N-bromosuccinimide (NBS) in acid medium, followed by determination of unreacted NBS by reacting it with a fixed amount of indigocarmine and measuring the absorbance at λmax 610 nm (method C) or methylene blue and measuring the absorbance at 626 nm (method D). the amount of NBS reacted corresponds to the amount of pesticide and the measured absorbance is found to increase linearly with the concentration of pesticide with correlation coefficients of 0.9991- 0.9998. The Beer’s law is obeyed in the concentration ranges 0.5-10.0 and 0.5-7.5 μg mL-1 (method C) and ranges 0.5- 8.0 and 0.5-10.0μg mL-1 (method D) for deltamethrin and dimethoate respectively.
2. Sensitive spectrophotometric determination of deltamethrin insecticide in its formulation and environmental samples
This technique, is based on the hydrolysis of deltamethrin with ethanolic KOH to form 3-phenoxy benzaldehyde which condensed with anthranilic acid (method E), 4-aminoantipyrine (method F) and 2-chlorophenyl hydrazine (method G) to form color product and the absorbance measured at λmax 480 nm (method E), 495 nm (method F) and 552 nm (method G). . The color derivatives were stable for 3, 5 and 6 days for methods A, B and C, respectively. The Beer’s law was obeyed over the concentration range of 0.2–2.0, 0.5-3.0 and 0.5–4.0 µg mL−1 for methods A, B and C, respectively.
The results showed that, the proposed methods are advantageous over other official or reported methods with respect to their higher sensitivity with apparent high molar absorptivity for determination of the studied pesticides. The proposed methods were successfully applied to determine the studied pesticides in their formulation, biological and environmental samples. The results obtained were compared statistically with other reported methods by student’s t-test (for accuracy) and variance ratio F-test (for precision) at the 95 % confidence level. The results showed that the t- and F- values were less than the critical tabulated value indicating that there was no significant difference between the proposed and official or reported methods. Thus the proposed spectrophotometric methods can be applied in routine analysis for determination of the studied pesticides in pure forms, formulations, biological and environmental samples .