الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
The present study aims to describe Green microextraction techniques for preconcentration and determination of some heavy metals in petroleum crude oils and environmental samples.
The thesis contains five chapters:
Chapter One:
Includes a general introduction about the importance of heavy metals, preconcentration techniques such as cloud point extraction (CPE), dispersive liquid–liquid microextraction (DLLME), and dispersive micro solid-phase extraction (DµSPE) methods,, leaching process, spectrophotometry, flame atomic absorption spectroscopy and the requirements of the validation of the methods (sensitivity of methods; precision and accuracy; detection and quantification limit and comparison of the results).
Chapter Two:
Describes a new, simple, rapid, sensitive and environmentally friendly ultrasound-assisted emulsification dispersive liquid–liquid microextraction (UAE-DLLME) has been developed for trace nickel Ni(II) separation and preconcentration in environmental samples prior to spectrophotometric determination. The proposed method based on using non-ionic water-soluble surfactant Triton X-114 (TX-114) as a disperser solvent and tetrachloroethylene as an extractive solvent. A 6-(1,3-thiazolylazo)-2-nitrophenol (TANP) as complexing agent was used for complexation of Ni(II) at pH 7.0.
Chapter Three:
A new, eco-friendly, and rapid ultrasound-assisted-cloud point extraction (UA-CPE) preconcentration technique was described for enrichment of vanadium V(V) in water, plant foodstuff and petroleum crude oil samples prior to its spectrophotometric determination. The developed method depended on chelation of V(V) with 2-amino-(1,3-thiazol-2-yldiazenyl) phenol (ATAP) in presence of H2O2 and H2SO4 (pH 2.0). A nonionic surfactant (Triton X-114) was utilized for extraction of the formed ternary complex with the aid of ultrasound energy.
Chapter Four:
Describes simple, and validated ultrasound-assisted dispersive micro solid-phase extraction (UA-DµSPE) method using modified multiwalled carbon nanotubes as a novel adsorbent for separation, preconcetration and determination of trace cobalt(II) and nickel(II) ions in various environmental samples was developed. The proposed method based on a modification of multiwalled carbon nanotubes (MWCNTs) with a new chelating agent 3-(2,6-dihydroxy-4-methylphen-1-ylazo)-1,2,4-triazole (DMPAT) which complexed with the analyte cobalt(II) and nickel(II) ions as a selective and efficient sorbent at pH 8.0 prior to their flame atomic absorption spectrometry determination.
Chapter Five:
Focuses on the recovery of vanadium from petroleum fly ash by carbon removal and the roast-leach process. The petroleum fly ash contained about 85% unburned carbon and 2.2% vanadium by weight. A vanadium-enriched product was obtained after carbon removal, and the vanadium content of this product was 19% by weight. Next, the vanadium-enriched product was roasted with sodium carbonate to convert vanadium oxides to water-soluble sodium metavanadate. The roasted sample was leached with water at 60 °C, and the extraction percentage of vanadium was about 89% by weight. Several analytical techniques, such as inductively coupled plasma atomic emission spectroscopy (ICP-AES), SEM image, EDAX and XRD analysis were utilized for sample analyses.