الفهرس 
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Abstract
This thesis consists of three parts in addition to the general introduction, references and a summary in Arabic. Each part includes an introduction, literature review, descriptive experimental work for the studied pesticides, results, discussion and ends with a conclusion.
CHAPTER I: Determination of Hexythiazox, Imidacloprid and Thiamethoxam Pesticides in Their Ternary Mixture
This part includes three sections.
Section (A): Introduction and literature Review
This section includes an introduction about the uses of Hexythiazox (HXZ), Imidacloprid (IMD) and Thiamethoxam (TXM), their chemical structure, physical properties and a review of the reported methods for their analysis in their formulations and in their ternary mixture.
Section (B): Determination of Hexythiazox, Imidacloprid and Thiamethoxam by
Different Spectrophotometric Methods
In this section, modified ratio difference, successive ratio derivative spectra and mean centering of ratio spectra spectrophotometric methods are applied for determination of HXZ, IMD and TXM in their ternary mixture using methanol as a solvent. The first method is modified ratio difference spectrophotometric method, where HXZ, IMD and TXM are determined by measuring ratio difference between 204.8-215.6, 215.6-217.6 and 217.2-228.4 nm, respectively. The second method is successive ratio derivative spectra spectrophotometric method using each of 3.10, 20.00 and 10.00 µg mL-1 of HXZ, IMD and TXM as a divisor, respectively, Δλ = 4 is used as a scaling factor; finally the amplitude values at 211.4, 205.4 and 230.8 nm are selected for determination of HXZ, IMD and TXM, respectively. The third method is mean centering of ratio spectra spectrophotometric method, where HXZ, IMD and TXM are determined by measuring the mean centered ratio spectra at 248, 207 and 228 nm, respectively. The proposed methods are applied for assay of HXZ, IMD and TXM in
pure forms, commercial formulations and in field samples; where acceptable results regarding to the agricultural pesticide committee of Egypt are obtained. The results obtained by applying the proposed methods for determination of HXZ, IMD and TXM in pure form are statistically compared to those obtained by the reported methods and no significant difference is found regarding to both accuracy and precision.
Section (C): Determination of Hexythiazox, Imidacloprid and Thiamethoxam by
Different chromatographic Methods
In this section, HPTLC-densitometric and RP-HPLC methods are developed for simultaneous determination of HXZ, IMD and TXM. The first method is HPTLC method; using silica gel HPTLC F254 plates as a stationary phase and methanol: chloroform: glacial acetic acid: triethyl amine (8.5: 1.5: 0.2: 0.1, by volume) as a developing system at 220 nm; the Rf values of the studied pesticides are
0.15, 0.35 and 0.60 for HXZ, IMD and TXM, respectively. The second method is RP-HPLC using isocratic elution, C18 column and a mobile phase consisting of acetonitrile: water (20: 80, v/v), pH 2.8 and UV detection at 225 nm; the retention time values are 2.13, 4.17 and 7.00 min for HXZ, IMD and TXM, respectively. The proposed methods are validated regarding to ICH guidelines and are successfully applied for assay of HXZ, IMD and TXM in pure form, commercial formulations and environmental samples. The results are within limit regarding to the agricultural pesticide committee of Egypt.
CHAPTER II: Determination of Mandipropamid, Metalaxyl, Thiophanate Methyl and Carbendazim Pesticides in Their Quaternary Mixture
This part includes three sections.
Section (A): Introduction and literature Review
This section includes an introduction about the uses of Mandipropamid (MND), Metalaxyl (MXL), Thiophanate methyl (TPM) and Carbendazim (CZM), their chemical structure, physical properties and a summary of the reported methods used for their analysis.
Section B: Determination of Mandipropamid, Metalaxyl, Thiophanate Methyl
and Carbendazim by Different Spectrophotometric Methods
In this section, derivative spectrophotometry and double divisor ratio spectra derivative spectrophotometric methods are applied for determination of MND, MXL, TPM and CZM in their quaternary mixture using 0.05 M HCL as a solvent. The first method is derivative spectrophotometry, where TPM is determined by first derivative 1D spectrophotometric method at 281 nm, while MND and CZM are determined by second derivative 2D spectrophotometric method at 236.4 and 256.2 nm, respectively. Finally MXL is determined by third derivative 3D spectrophotometric method at 221.6 nm. The second method is double divisor ratio spectra derivative (DDRD) spectrophotometry which allows the determination of both MND at 289 nm and MXL at 233.2 nm using a double divisor of 30 μg mL-1 of each of TPM and CZM, while TPM and CZM are determined at 259 and 267.4 nm, respectively, using a double divisor of 4 μg mL-1 of each of MND and MXL. The proposed methods are applied for assay of MND, MXL, TPM and CZM in pure form, commercial formulations and in field samples showing acceptable results regarding to the agricultural pesticide committee of Egypt. The results obtained by applying the proposed methods for determination of MND, MXL, TPM and CZM in pure form are statistically compared to those obtained by a reported methods and no significant difference is found regarding to both accuracy and precision.
Section C: Determination of Mandipropamid, Metalaxyl, Thiophanate Methyl
and Carbendazim by Different chromatographic Methods
In this section, HPTLC-densitometric and RP-HPLC methods are developed for simultaneous determination of MND, MXL, TPM and CZM. The first method is HPTLC method, using silica gel HPTLC F254 plates as a stationary phase and hexane: methanol: acetone: glacial acetic acid (7.5: 2: 0.5: 0.1, by volume) as a developing system at 220 nm; the Rf values of the studied pesticides are
0.84, 0.72, 0.42 and 0.21 for MND, MXL, TPM and CZM, respectively. The second method is RP-HPLC using isocratic elution, C18 column and a mobile phase consisting of acetonitrile: 0.02 M KH2PO4 buffer (25: 75, v/v), pH 4 with orthophosphoric acid, at a flow rate of 1 ml min-1 with UV detection at 225 nm; the retention time values are 6.19, 4.98, 3.31 and 2.16 min for MND, MXL, TPM and CZM, respectively. The proposed methods are validated regarding to ICH guidelines and are successfully applied for assay of MND, MXL, TPM and CZM in pure form, commercial formulations and environmental samples. The results obtained are within limits regarding to the agricultural pesticide committee of Egypt.
CHAPTER III: Determination of Acetamiprid, Flutolanil and Etofenprox Pesticides in Their Ternary Mixture
This part includes three sections.
Section (A): Introduction and literature Review
This section includes an introduction about the uses of Acetamiprid (ACP), Flutolanil (FLL) and Etofenprox (EPX), their chemical structure, physical properties and a summary of the reported methods for their analysis in their formulations and in their ternary mixture.
Section (B): Determination of Acetamiprid, Flutolanil and Etofenprox by
Different Spectrophotometric Methods
In this section, derivative spectrophotometry, differential dual wavelength spectrophotometry, modified ratio difference and mean centering of ratio spectra spectrophotometric methods are applied for determination of ACP, FLL and EPX in their ternary mixture using methanol as a solvent. The first method is derivative spectrophotometry, where ACP and FLL are determined by second derivative 2D spectrophotometric method at 270.8 and 262.6 nm, respectively, while EPX is determined by third derivative 3D spectrophotometric method at 233.4 nm. The second method is differential dual wavelength spectrophotometry where ACP is determined by measuring the amplitude difference at the wavelengths 264.8 and 277 nm, FLL at the wavelengths 229 and 241 nm and EPX at the wavelengths 225.6 and 243. The third method is modified ratio difference spectrophotometric method, where ACP, FLL and EPX are determined by measuring ratio difference between 261.2-241, 273.4-236.8 and 269.8-232 nm, respectively. The fourth method is mean centering of ratio spectra spectrophotometric method, where ACP, FLL and EPX are determined by measuring the mean centered ratio spectra at 284, 293 and 224 nm, respectively. The proposed methods are applied for the assay of ACP, FLL and EPX in pure form, commercial formulations and in field samples where acceptable results regarding to the agricultural pesticide committee of Egypt are obtained. The results obtained by applying the proposed methods for determination of ACP, FLL and EPX in pure form are statistically compared to those obtained by applying the reported methods and no significant difference is found regarding to both accuracy and precision.
Section (C): Determination of Acetamiprid, Flutolanil and Etofenprox by
Different chromatographic Methods
In this section, HPTLC-Densitometric and HPLC methods are developed for simultaneous determination of ACP, FLL and EPX. The first method is HPTLC method; using silica gel HPTLC F254 plates as a stationary phase and methanol: hexane: acetone: glacial acetic acid (8: 2: 0.5: 0.1, by
volume) as a developing system at 220 nm; the Rf values of the studied pesticides are 0.30, 0.45 and 0.71 for ACP, FLL and EPX, respectively. The second method is HPLC using isocratic elution, C8 column and mobile phase consisting of acetonitrile: water (75: 25, v/v), pH 2.87 with UV detection at 225 nm; the retention time values are 5.68, 7.50 and 9.01 min for ACP, FLL and EPX, respectively. The proposed methods are validated regarding to ICH guidelines and are successfully applied for the assay of ACP, FLL and EPX in pure form, commercial formulations and environmental samples. The results obtained are within limit regarding to the agricultural pesticide committee of Egypt.
This thesis refers to 167 references, contains 40 tables, 117 figures and ends with an arabic
abstract.