Silica based nanoscavengers for the determination of environmental pollutants using solid phase dispersion extraction
Silica based nanoscavengers for the determination of environmental pollutants using solid phase dispersion extraction
This thesis introduces newly developed nanoscavengers for the extraction and pre-concentration of harmful substances from water samples, using a new solid phase dispersion extraction technique (SPDE). This technique is based on the dispersion of 250nm diameter, modified silica particles (nanoscavengers) in water samples, to extract the analytes.
Uniform silica particles were synthesised by both a conventional sol-gel process and a new spray technique.
Different types of nanoscavenger were synthesised by modification of the silica with a number of silane coupling agents, such as N-[3-(trimethoxysilyl)propyl]-ethylenediamine and its dithiocarbamate, 3-mercaptopropyltrimethoxysilane, octadecyltrichlorosilane and octadecyltrimethoxysilane. The modification step was carried out by two different processes: the modification of pre-formed 250 nm silica particles and by a single-pot synthesis.
The amino-nanoscavenger, when applied to the pre-concentration of copper from water gave a recovery of 98%. A dithiocarbamate-nanoscavenger was applied to the pre-concentration of cadmium, copper, lead and nickel and recoveries were 99, 97, 91 and 92%, respectively. Inorganic mercury and arsenic were pre-concentrated using a mercapto-nanoscavenger, and recoveries of 106 and 96% were obtained, respectively.
The collection of organic species using the C18-nanoscavenger resulted in the recovery of 70% di-n-butyl phthalate. Herbicides such as Atrazine, Ramrod, Diuran and Propazine were recovered with efficiencies of 66, 78, 82 and 59% respectively. A dual-functionality-nanoscavenger was employed for the pre-concentration of 22 chlorinated pesticides, and recoveries varied from 70 to 100%. Polynuclear aromatic hydrocarbons (PAHs) were also pre-concentrated from water samples using this dual-functionality-nanoscavenger, and recoveries of 13 PAHs varied from 70 to 100%.
Nanoscavenger based solid phase dispersion extraction ‘SPDE’ offers many advantages over conventional approaches. These include the minimization of reagents, transportability, field application and efficiency.
University of Southampton
Khdary, Nezar Hassan Mohammed
2006
Khdary, Nezar Hassan Mohammed
Khdary, Nezar Hassan Mohammed
(2006)
Silica based nanoscavengers for the determination of environmental pollutants using solid phase dispersion extraction.
University of Southampton, Doctoral Thesis.
Record type:
Thesis
(Doctoral)
Abstract
This thesis introduces newly developed nanoscavengers for the extraction and pre-concentration of harmful substances from water samples, using a new solid phase dispersion extraction technique (SPDE). This technique is based on the dispersion of 250nm diameter, modified silica particles (nanoscavengers) in water samples, to extract the analytes.
Uniform silica particles were synthesised by both a conventional sol-gel process and a new spray technique.
Different types of nanoscavenger were synthesised by modification of the silica with a number of silane coupling agents, such as N-[3-(trimethoxysilyl)propyl]-ethylenediamine and its dithiocarbamate, 3-mercaptopropyltrimethoxysilane, octadecyltrichlorosilane and octadecyltrimethoxysilane. The modification step was carried out by two different processes: the modification of pre-formed 250 nm silica particles and by a single-pot synthesis.
The amino-nanoscavenger, when applied to the pre-concentration of copper from water gave a recovery of 98%. A dithiocarbamate-nanoscavenger was applied to the pre-concentration of cadmium, copper, lead and nickel and recoveries were 99, 97, 91 and 92%, respectively. Inorganic mercury and arsenic were pre-concentrated using a mercapto-nanoscavenger, and recoveries of 106 and 96% were obtained, respectively.
The collection of organic species using the C18-nanoscavenger resulted in the recovery of 70% di-n-butyl phthalate. Herbicides such as Atrazine, Ramrod, Diuran and Propazine were recovered with efficiencies of 66, 78, 82 and 59% respectively. A dual-functionality-nanoscavenger was employed for the pre-concentration of 22 chlorinated pesticides, and recoveries varied from 70 to 100%. Polynuclear aromatic hydrocarbons (PAHs) were also pre-concentrated from water samples using this dual-functionality-nanoscavenger, and recoveries of 13 PAHs varied from 70 to 100%.
Nanoscavenger based solid phase dispersion extraction ‘SPDE’ offers many advantages over conventional approaches. These include the minimization of reagents, transportability, field application and efficiency.
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Published date: 2006
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Local EPrints ID: 466431
URI: http://eprints.soton.ac.uk/id/eprint/466431
PURE UUID: 526ebb12-985b-403f-a4c6-2df33e632b86
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Date deposited: 05 Jul 2022 05:16
Last modified: 05 Jul 2022 05:16
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Author:
Nezar Hassan Mohammed Khdary
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