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In Vivo Detection of Trace Organic Contaminants in Fish Using Solid Phase MicroextractionWang, Shuang 18 October 2010 (has links)
The feasibility of using solid phase micro-extraction (SPME) as an in vivo sampling tool for analysis of trace environmental contaminants in fish exposed to municipal wastewater effluents (MWWEs) was validated using controlled laboratory and field experiments. SPME was compared with traditional extraction techniques, including solid phase extraction (SPE) in water and solid-liquid extraction (SLE) in fish tissues to assess relative efficiencies. All three techniques were used to quantify the presence of eight compounds of interest in fish exposed to MWWEs in the laboratory, as well as in wild and field caged fish upstream and downstream of three wastewater treatment plants in the Grand River watershed. Atrazine, carbamazepine, naproxen, diclofenac, gemfibrozil, bisphenol A, fluoxetine and ibuprofen were selected as target compounds due to their diverse chemical characteristics and frequent detection in surface waters and sediments around the world. The distribution coefficients between various sample matrices (water, fish) and extraction phases (SPME fibers) were compared, as were extraction profiles and bioconcentration factors of target analytes in muscle of fish exposed to MWWEs under laboratory conditions, during field caging studies, or collected (wild) from the Grand River. Poly(dimethylsiloxane) (PDMS) medical grade tubing was utilized as the SPME extraction phase, which when kinetically calibrated, were effective at extracting and quantifying the target analytes from both water and fish tissue relative to traditional techniques. Caged and in wild fish exposed to MWWEs from all three municipal treatment plants bio-accumulated detectable levels of several of the target chemicals. All target analytes (except for fluoxetine) were identified in the MWWEs and exposed fish by SPME at low concentrations (ng/L). The presence and concentration of the targeted analytes in both water and wild fish living in the Grand River watershed varied with season and proximity to the wastewater outfalls. Results demonstrate that properly applied SPME can detect and quantify selected contaminants in fish tissues, surface water, and wastewater effluents. In vivo SPME allows for non-lethal sampling of fish, which creates the opportunity for monitoring contaminant exposure in receiving environments influenced by MWWEs or non-point-source runoff while minimizing the impact on the organisms.
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High-throughput analysis of biological fluids using 96-blade (thin-film) solid phase microextraction systemMirnaghi, Fatemeh Sadat January 2012 (has links)
The initial research of this thesis involves the evaluation of different strategies for developing diverse chemistries of highly stable coatings for the automated 96-blade (thin-film) solid phase microextraction (SPME) system. Thin-film geometry increases the volume of extractive phase, and consequently improves the sensitivity of the analysis. Sol-gel technology was used for the preparation of octadecyl (C18)-silica gel thin-film coating. The evaluation of the C18-silica gel SPME extractive phase resulted in stable physical and chemical characteristics and long-term reusability with a high degree of reproducibility.
Biocompatible polyacrylonitrile (PAN) polymer was used for the preparation of particle-based extractive phases in order to improve the biocompatible characteristics of SPME coatings for the extraction from biological samples.
Three different immobilization strategies were evaluated for developing highly stable coatings for the automated 96-blade SPME system. The spraying was found to be the optimal method in terms of stability and reusability for long-term use.
The optimized C18-PAN coating demonstrated improved biocompatibility, stability, and reusability for the extraction of benzodiazepines from human plasma in comparison with those of C18-silica gel coating.
To improve the biocompatible properties of the C18-PAN SPME coating for long-term direct analysis from whole blood, different modification strategies were studied and evaluated. The modification of the coating with an extra layer of biocompatible polyacrylonitrile resulted in significant improvement in the blood compatibility in long-term use.
‘Extracted blood spot’ (EBS) sampling was introduced as a novel approach to overcome the limitations of dried blood spot sampling. EBS includes the application of a biocompatible SPME coating for spot sampling of blood or other biofluids. The compatibility of EBS sampling with different analytical methods was demonstrated. The utilization of EBS as a fast sampling and sample preparation method resulted in a significant reduction of matrix effects through efficient sample clean-up.
Modified polystyrene-divinylbenzene (PS-DVB)-PAN and phenylboronic acid (PBA)-PAN 96-blade SPME coatings were developed and evaluated for the extraction of analytes in a wide range of polarity. These coatings demonstrated efficient extraction recovery for both polar and non-polar groups of compounds, and presented chemical and mechanical stabilities and reproducible extraction efficiencies for more than 100 usages in biological sample.
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Detection of aldehydes in lung cancer cell culture by gas chromatography/mass spectrometry and solid-phase microextraction with on-fiber derivatizationShan, Guangqing 17 September 2007 (has links)
Aldehydes in lung cancer cell culture have been investigated using gas chromatography/mass spectrometry and solid-phase microextraction with on-fiber derivatization. In this study, the poly(dimethylsiloxane/divinylbenzene (PDMS/DVB) fiber was used and o-2,3,4,5,6-(pentafluorobenzyl) hydroxylamine hydrochloride (PFBHA) was first loaded on the fiber. Aldehydes in the headspace of lung cancer cell culture were extracted by solid-phase microextraction (SPME) fiber and subsequently derivatized by PFBHA on the fiber. Finally, the aldehyde oximes formed on the fiber were analyzed by gas chromatography/mass spectrometry (GC/MS). Using this method, acetaldehyde decrease was found in both non-small lung cancer cell cultures studied compared to the medium control study. The results of spiking the cell culture with acetaldehyde solution showed that 5 million SK-MES-1 cell lines could consume up to 4.5 uM acetaldehyde in 15-ml medium, and 5 million NCI-H522 cell lines could consume 5.9 uM acetaldehyde in 15-ml medium. The decrease of acetaldehyde may contribute to the metabolism of lung cancer cells. It was proved that GC/MS and SPME with on-fiber derivatization is a simple, rapid, sensitive and solvent-free method for the detection of aldehydes in lung cancer cell culture.
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Evaluation of a solid phase microextraction method for community-based monitoring of 1,3-butadiene and benzene in Houston, Texas.Broyles, Gregory M. Symanski, Elaine, Stock, Thomas H. Maxwell, Taylor J. January 2009 (has links)
Source: Masters Abstracts International, Volume: 47-06, page: 3475. Advisers: Elaine Symanski; Thomas H. Stock. Includes bibliographical references
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In Vivo Detection of Trace Organic Contaminants in Fish Using Solid Phase MicroextractionWang, Shuang 18 October 2010 (has links)
The feasibility of using solid phase micro-extraction (SPME) as an in vivo sampling tool for analysis of trace environmental contaminants in fish exposed to municipal wastewater effluents (MWWEs) was validated using controlled laboratory and field experiments. SPME was compared with traditional extraction techniques, including solid phase extraction (SPE) in water and solid-liquid extraction (SLE) in fish tissues to assess relative efficiencies. All three techniques were used to quantify the presence of eight compounds of interest in fish exposed to MWWEs in the laboratory, as well as in wild and field caged fish upstream and downstream of three wastewater treatment plants in the Grand River watershed. Atrazine, carbamazepine, naproxen, diclofenac, gemfibrozil, bisphenol A, fluoxetine and ibuprofen were selected as target compounds due to their diverse chemical characteristics and frequent detection in surface waters and sediments around the world. The distribution coefficients between various sample matrices (water, fish) and extraction phases (SPME fibers) were compared, as were extraction profiles and bioconcentration factors of target analytes in muscle of fish exposed to MWWEs under laboratory conditions, during field caging studies, or collected (wild) from the Grand River. Poly(dimethylsiloxane) (PDMS) medical grade tubing was utilized as the SPME extraction phase, which when kinetically calibrated, were effective at extracting and quantifying the target analytes from both water and fish tissue relative to traditional techniques. Caged and in wild fish exposed to MWWEs from all three municipal treatment plants bio-accumulated detectable levels of several of the target chemicals. All target analytes (except for fluoxetine) were identified in the MWWEs and exposed fish by SPME at low concentrations (ng/L). The presence and concentration of the targeted analytes in both water and wild fish living in the Grand River watershed varied with season and proximity to the wastewater outfalls. Results demonstrate that properly applied SPME can detect and quantify selected contaminants in fish tissues, surface water, and wastewater effluents. In vivo SPME allows for non-lethal sampling of fish, which creates the opportunity for monitoring contaminant exposure in receiving environments influenced by MWWEs or non-point-source runoff while minimizing the impact on the organisms.
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DEVELOPMENT OF AN EXTRACTION METHOD FOR THE MASS SPECTRAL ANALYSIS OF ORGANIC GUNSHOT RESIDUE FROM CLOTHINGCasper, Brent 01 January 2015 (has links)
This dissertation will focus on the extraction of volatile organic compounds associated with gunshot residue from articles of clothing, followed by analysis with mass spectrometry. During the discharge of a weapon, a cloud of volatile organic gunshot residue (OGSR) is dispersed around a firearm. This will create a high probability of transfer between the OGSR and the clothing of individuals who are near a discharged weapon.
The first part of this dissertation will be the development of a method for removal of volatile OGSR from articles of clothing. Extraction of OGSR will be completed by solid phase microextraction (SPME), followed by separation and analysis by gas chromatography-mass spectrometry (GC/MS). Many parameters will require optimization for proper extraction of OGSR from articles of clothing. Following development of a SPME procedure, figures of merit were determined such as linearity and limits of detection/quantification, obtaining levels of detection of 0.206 ng/cm2 on a 100 cm2 cotton cloth. Applications of this extraction method were investigated including the determination of the distance OGSR travels from a discharged weapon and the extraction of OGSR with different clothing materials by SPME.
The second part of this dissertation will focus on the development of an on-line solvent extraction method for removal of OGSR from articles of clothing, followed by analysis with paper spray mass spectrometry. Issues using SPME of certain types of clothing materials required the development of an alternative method for removal of OGSR from articles of clothing. Use of an on-line solvent extraction technique of OGSR from articles of clothing followed by analysis with paper spray mass spectrometry allowed for detection of OGSR at comparable levels to a headspace SPME procedure. Use of paper spray with an ion trap mass spectrometer permitted the soft ionization of OGSR compounds followed by tandem mass spectrometry to obtain structural information.
Extraction of OGSR from articles of clothing has potential to determine if an individual was present during the discharge of a firearm. Extraction of OGSR from articles of clothing will provide an alternative to traditional methods of gunshot residue analysis currently in use.
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Optimization of a Needle Trap DeviceZhan, Weiqiang 09 1900 (has links)
Various needle trap devices (NTDs) with different designs for different applications have been developed during the past decade. A theoretical model on the fundamentals of the NTD was recently proposed, which employed the theory of frontal (gas-solid) chromatography to describe the sampling process, where a gaseous sample was continuously introduced into the sorbent bed. In this investigation, different types of sorbent particles with different dimensions were packed into the needle as adsorbents. The effect of particle dimension, which would affect the packing density and consequently the capacity, the extraction efficiency, and desorption efficiency of the NTD were experimentally investigated and the proposed theory was validated. The results demonstrated that NTDs packed with small particles possess higher extraction capacity and efficiency but much higher resistance to flow as well. The higher resistance did not necessarily result in poor desorption efficiency, because desorption efficiency was affected by both the sorbent bed structure and the desorption gas flow. The relationships observed among those physical parameters provide valuable guidance on how to design an NTD with high performance potential for future applications. For particulate sampling, it was found that NTDs packed with different particles presented high collection efficiency of the particulates being investigated, and the collection efficiency was dominated by the pore size and distribution of the sorbent bed packed inside the needle. Collection efficiency also increased with increase in solidity of the sorbent bed; the increase in humidity of the aerosol sample; and the decrease of sampling rate. The results also provide valuable guidance on the optimisation of needle trap for particulate collection.
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High-throughput analysis of biological fluids using 96-blade (thin-film) solid phase microextraction systemMirnaghi, Fatemeh Sadat January 2012 (has links)
The initial research of this thesis involves the evaluation of different strategies for developing diverse chemistries of highly stable coatings for the automated 96-blade (thin-film) solid phase microextraction (SPME) system. Thin-film geometry increases the volume of extractive phase, and consequently improves the sensitivity of the analysis. Sol-gel technology was used for the preparation of octadecyl (C18)-silica gel thin-film coating. The evaluation of the C18-silica gel SPME extractive phase resulted in stable physical and chemical characteristics and long-term reusability with a high degree of reproducibility.
Biocompatible polyacrylonitrile (PAN) polymer was used for the preparation of particle-based extractive phases in order to improve the biocompatible characteristics of SPME coatings for the extraction from biological samples.
Three different immobilization strategies were evaluated for developing highly stable coatings for the automated 96-blade SPME system. The spraying was found to be the optimal method in terms of stability and reusability for long-term use.
The optimized C18-PAN coating demonstrated improved biocompatibility, stability, and reusability for the extraction of benzodiazepines from human plasma in comparison with those of C18-silica gel coating.
To improve the biocompatible properties of the C18-PAN SPME coating for long-term direct analysis from whole blood, different modification strategies were studied and evaluated. The modification of the coating with an extra layer of biocompatible polyacrylonitrile resulted in significant improvement in the blood compatibility in long-term use.
‘Extracted blood spot’ (EBS) sampling was introduced as a novel approach to overcome the limitations of dried blood spot sampling. EBS includes the application of a biocompatible SPME coating for spot sampling of blood or other biofluids. The compatibility of EBS sampling with different analytical methods was demonstrated. The utilization of EBS as a fast sampling and sample preparation method resulted in a significant reduction of matrix effects through efficient sample clean-up.
Modified polystyrene-divinylbenzene (PS-DVB)-PAN and phenylboronic acid (PBA)-PAN 96-blade SPME coatings were developed and evaluated for the extraction of analytes in a wide range of polarity. These coatings demonstrated efficient extraction recovery for both polar and non-polar groups of compounds, and presented chemical and mechanical stabilities and reproducible extraction efficiencies for more than 100 usages in biological sample.
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Recovery Of Strawberry Aroma Compounds By PervaporationIsci, Asli 01 July 2004 (has links) (PDF)
Pervaporation is a selective membrane technique in which a liquid feed mixture is separated by means of partial vaporization through a non-porous perm-selective membrane. This method can be used for the recovery of heat sensitive aroma compounds to avoid them from thermal damage in beverage industries.
The main objective of this study was to determine the effects of feed temperature (30, 40, 50° / C), composition (different model solutions, strawberry essence), concentration (50, 100, 150 ppm) and permeate pressure (4, 8 mbar) on the recovery of aroma compounds of strawberry by pervaporation in terms of mass flux and selectivity.
In addition, it was aimed to optimize the extraction conditions (extraction time, temperature, agitation speed, strawberry matrix) of Solid-phase microextraction (SPME), which is used for the analysis of strawberry aroma compounds. Optimum results for SPME were obtained at 40° / C, 700 rpm for 30 min and no matrix effect was observed.
Pervaporation experiments were performed using a hydrophobic membrane, PERVAP 1070 (PDMS). As the feed temperature increased, the mass flux and selectivity increased and the total mass flux followed an Arrhenius type relation. Decreasing downstream pressure increased both total flux and selectivity, while increase in feed concentration led to higher organic fluxes but lower selectivities.
In general, PERVAP 1070 showed a higher selectivity towards Methyl butyrate (MTB) than Ethyl butyrate (ETB) and MTB flux was affected negatively by the presence of ETB in the feed solution. Pervaporation experiments were also performed with a strawberry essence and strawberry model solution. The selectivities of MTB and ETB were negatively affected by the presence of other aroma compounds.
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Comparison of volatile organic compound profiles of various sources of decompositionLavigne, Skye Elizabeth-Hinkley 25 October 2018 (has links)
The ability to locate human remains, specifically in a forensic setting, is crucial to investigations. Research in the past two decades has identified volatile organic compounds (VOCs) as the source of the decomposition odor. The study examined the headspace (area directly above) of decomposing remains, Sigma-Aldrich (St. Louis, MO) Pseudo Corpse Scents (formulations one and two), cadaveric blood, and decompositional fluid for target VOCs to which human remains detection (HRD) dogs could indicate. These samples were tested using solid-phase microextraction (SPME) and a gas chromatograph-mass spectrometer (GC/MS) for the exact odor profile and compared to literature about VOCs present in decomposition. The author hypothesized that a series of seven target chemical compounds (carbon disulfide, hexanal, nonanal, dimethyl sulfide, dimethyl disulfide, styrene, and benzoic acid methyl ester) would be present when the headspace of all samples tested. Ideally, a synthetic compound that will better mimic human decomposition odor profile can be created to aid in the training of HRD dogs. There are some disadvantages to using dogs in the field, and the lack of standardization when training HRD dogs is a major one. By examining VOC profiles of different sources of decomposition, a core set of VOCs of human decomposition may be identified to aid in the standardization of training. Of the eight target compounds chosen from the literature, only two were found in any samples tested for this experiment, hexanal and nonanal found in pig heart, deer liver, as well as human muscle and epidermis. Acetic acid was identified in every sample with the exception of the control. Also, in accordance with the literature, putrescine and cadaverine were not found in any of the samples.
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