The study of hydrogen and the understanding of its response to extended pressure and temperatures is of great importance due to its significant universal abundance. Hydrogen is currently not well understood in these extended regimes due to it being inherently difficult to work with experimentally as well as having a poor response to a wide range of diagnostics. Consequently, there have been long standing predicted phenomena which still remain experimentally elusive: (1) melting driven by large zero point oscillations [Brovman 72] and (2) adopting a purely atomic state at higher pressures [Wigner 35]. Coupling high-pressure, high-temperature techniques with in-situ optical diagnostics, the stability of the solid phases of hydrogen were evaluated over an extended pressure-temperature regime. The first ever H2 solid-solid transitions above 300 K are reported and the evolution of the I-IV phase line after the III-IV-I triple point is constrained. A transition which could be attributed to melting is observed at 480 K and 225 GPa, the lowest known melting temperature for any material under these conditions. A new triple point between phase I-IV-Liquid is identified, the third known triple point in the phase diagram and the first on the melting curve. The possible continuations of the melting line are discussed, ultimately revising the melting transition at 300 K and at 0 K to much higher pressures than previously thought [Bonev 04]. The contributing work also marks a new high pressure achievement, obtaining some of the highest ever recorded static pressures in the laboratory. Hydrogen and its heavier isotopes hydrogen deuteride and deuterium were compressed to pressures of 384 GPa, 388 GPa and 380 GPa respectively. These experimental data are indicative that above 325 GPa H2 and HD adopt a new solid phase, phase V. Analysis of the spectra over the IV-V transition is suggestive that under compression the molecular bonding in the G-layers of the Pc structure lengthen and symmetrise, evolving into the Ibam structure. It is speculated that this phase could be a precursor to the elusive, purely atomic I41/amd structure predicted to be stable at higher pressures (>400 GPa) [McMahon 11, Azadi 14].

Submitted in fulfillment of the requirement for the degree Master of Applied Sciences in Chemistry, Durban University of Technology, Durban, South Africa, 2017. / In this study, molecular modeling was used to investigate the intermolecular interactions between the functional monomer and ketoprofen which is an acidic pharmaceutical that possesses anti-inflammatory and analgesic activities. Ketoprofen is widely employed in medical care for treating musculoskeletal injury. This led to rational design of a molecularly imprinted polymer (MIP) that is selective to ketoprofen. Density functional theory (DFT) at B3LYP/6-31 level was used to investigate the intermolecular interaction between functional monomers and ketoprofen. Binding energy, ΔE, was used as an indication of the strength of the interaction that occurs between functional monomers and ketoprofen. 2-vinylpyridine (2-VP) as one of the functional monomers gave the lowest binding energy when compared to all the functional monomers investigated. Monomer-template interactions were further experimentally investigated using spectroscopic techniques such as Ultraviolet-visible and Fourier transform infrared (FTIR). A selective MIP for ketoprofen was synthesized using 2-vinylpyridine, ethylene glycol dimethacrylate, 1,1’-azobis(cyclohexanecarbonitrile), toluene/acetonitrile (9:1, v/v), and ketoprofen as a functional monomer, cross-linker, initiator, porogenic mixture, and template, respectively. The polymerization was performed at 60 °C for 16 h, and thereafter the temperature was increased to 80 °C for 24 h to achieve a solid monolith polymer. The non-imprinted polymer (NIP) was synthesized in a similar manner with the omission of ketoprofen. Characterization with thermogravimetric analysis (TGA) and powder X-ray diffraction (XRD) showed that the synthesized polymers were thermally stable and amorphous. Morphology of the particles were clearly visible, with MIP showing rough and irregular surface compared to NIP on the scanning electron microscopy (SEM). The characterization of the prominent functional groups on both MIP and NIP were performed using FTIR and nuclear magnetic resonance (NMR). The existence of hydroxyl was observed in the MIP; this was due to the presence of ketoprofen in the cavity. Prominent carbonyl group was an indication of the cross-linker present in both polymers. The synthesized MIP was applied as a selective sorbent in the solid-phase extraction of ketoprofen from the water. The extracted ketoprofen was monitored by high performance liquid chromatography (HPLC) coupled with UV/Vis detector. Several parameters were investigated for maximum recovery of ketoprofen from the spiked deionized water. The optimum method involved the conditioning of 14 mg MIP sorbent with 5 mL of methanol followed by equilibrating with 5 mL of deionized water adjusted to pH 2.5. Thereafter, 50 mL sample (pH 5) was loaded into the cartridge containing MIP sorbent followed by washing and eluting with 1% TEA/H2O and 100% methanol, respectively. Eluted compounds were quantified with HPLC. MIP was more selective to ketoprofen in the presence of other structural related competitors. The analytical method gave detection limits of 0.23, 0.17, and 0.09 mg L-1 in wastewater influent, effluent, and deionized water, respectively. The recovery for the wastewater influent and effluent spiked with 5 µg L-1 of ketoprofen was 68%, whereas 114% was obtained for deionized water. The concentrations of ketoprofen in the influent and effluent samples were in the ranges of 22.5 - 34.0 and 1.14 - 5.33 mg.L-1, respectively. The relative standard deviation (RSD) given as ± values indicates that the developed analytical method for the analysis of ketoprofen in wastewater was rapid, affordable, accurate, precise, sensitive, and selective. / M

Please read the abstract in the section 00front of this document / Thesis (PhD (Chemistry))--University of Pretoria, 2005. / Chemistry / unrestricted

The use of capillary electrophoresis (CE) has been restricted to applications having high sample concentrations because of its low sensitivity caused by small injection volumes and, when ultraviolet (UV) detection is used, the short optical path length. Sensitivity in CE can be improved by using more sensitive detection systems, or by preconcentration techniques which are based on chromatographic and/or electrophoretic principles. One of the promising strategies to improve sensitivity is solid phase extraction (SPE). Solid Phase Extraction utilizes high sample volumes and a variety of complex matrixes to facilitate trace detection. To increase the specificity of the SPE a selective solid phase must be chosen. Immunosorbents, which are a combination of an antibody and a solid support, have proven to be an excellent option because of high selectivity of the antibody. This thesis is an exploratory study of the application of immunosorbent-SPE combined with CE for trace concentration of benzodiazepines. This research describes the immobilization and performance evaluation of an immunosorbent prepared by immobilizing a benzodiazepine-specific antibody on aminopropyl silica. The binding capacity of the immunosorbent, measured as µg of benzodiazepine/ gram of immunosorbent, was 39 ± 10. The long term stability of the prepared immunosorbent has been improved by capping the remaining aminopropyl groups by reaction with acetic anhydride. The capped immunosorbent retained its binding capacity after several uses.

Indiana University-Purdue University Indianapolis (IUPUI) / In Headspace Solid-Phase Microextraction (Headspace SPME), a sample is heated to encourage a portion of the analyte into the headspace of a vial. A coated fiber is introduced into the sample headspace and the analyte is adsorbed onto the fiber coating. Total Vaporization Solid-Phase Microextraction (TV-SPME) is a technique that is derived from this technique. In TV-SPME, liquid samples are completely vaporized allowing for better adsorption and fewer matrix effects. This method does not require any sample preparation, utilizes minimal supplies and can be automated, making it both an efficient and cost-effective method. Chapter 1 will discuss the theory of SPME and TV-SPME. In Chapter 2, the detection of ɣ-hydroxybutyric acid (GHB) and ɣ-butyrolactone (GBL) in beverages is discussed. The detection of these compounds in beverages is of importance because these drugs may be used to facilitate sexual assault. This crime utilizes substances that cause sedation and memory loss. The derivatization of GHB as well as the properties that make GHB difficult to detect will be discussed. Chapter 3 will discuss the detection of methamphetamine and amphetamine (as their trifluoroacetyl derivatives), GBL, and the trimethylsilyl derivative of GHB in human urine. Amphetamine is a metabolite of methamphetamine, therefore, both drugs should be identified within biological samples. GHB and GBL are metabolites of one another and interconvert when in aqueous solution. This interconversion will be discussed. Chapter 4 will cover method optimization of the Total Vaporization Solid-Phase Microextraction method. Analytes of interest for these analyses were methamphetamine, amphetamine, GHB, and GBL. The optimal extraction temperature ranging from 60-160°C of each drug will be discussed as well as why higher temperatures may not be suitable for this method. A limit of detection study for methamphetamine and amphetamine will also be covered. Chapter 5, the future work chapter, will discuss future analyses using the Total Vaporization Solid-Phase Microextraction method including the analysis of powder materials, plant material, and toxicological samples. Powder material will include the analysis of individual powdered drugs as well as realistic drug mixtures. Some analyses on individual powder samples has already been completed and will be shown. Plant material will include the analysis of naturally occurring compounds found in marijuana plants as well as synthetic cannabinoids. Toxicological samples will expand on previously mentioned urine samples to include drugs such as benzoylecgonine and THC-COOH.

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第20929号 / 理博第4381号 / 新制||理||1630(附属図書館) / 京都大学大学院理学研究科化学専攻 / (主査)教授 杉山 弘, 教授 三木 邦夫, 教授 秋山 芳展 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

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The utilization of activated sludge as feedstock for biofuel and oleochemical production was investigated. Initial studies included optimization of biodiesel production from this feedstock through in situ transesterification. Results of these studies indicated that activated sludge biodiesel is not economically viable. This was primarily due to relatively low yields and the high economics of feedstock dewatering. Strategies to increase biofuel yield from activated sludge were then evaluated. Bacterial species present in activated sludge are known to produce a wide variety of lipidic compounds as carbon and energy storage material and as components of their cellular structures. In addition to lipidic compounds, activated sludge bacteria might also contain other compounds depending on wastewater characteristics. Among these bacterial compounds, only the saponifiable ones can be converted to biodiesel. The unsaponifiable compounds present in the activated sludge are also important, not only for biofuel production, but also for a wide variety of applications. Characterization of lipids in activated sludge revealed that it contains significant amount of polyhydroxyalkanoates, wax esters, acylglycerides and fatty acids. It also contains Template Created By: James Nail 2010 sterols, steryl esters and phospholipids as well as small but detectable amounts of hydrocarbons. This indicated that activated sludge could be also an inexpensive source of oleochemicals. Another strategy that was evaluated was lipid-enhancement by fermentation of activated sludge. Since the majority of products from petroleum oil are used as transportation fuel, the aim here was to increase the saponifiable lipids in activated sludge bacteria by applying a biochemical stimulus (i.e. high C:N ratio). Results showed that application of this stimulus increased the amount of saponifiable lipids, particularly triacyglycerides, in the activated sludge. Furthermore, fermentation homogenized the lipids in the sludge regardless of its source. This solidified the concept of utilizing wastewater treatment facilities as biorefineries. To support the utilization of other compounds in raw activated sludge for biofuel production, a model compound was chosen for catalytic cracking experiments. Results indicated that catalytic cracking of 1-octadecanol over H+ZSM5 proceeds via dehydration, producing octadecene. The octadecene then undergoes a series of reactions including β-C─C bond scission, alkylation, oligomerization, dehydrocyclization and aromatization producing aromatics, paraffins and olefins suitable for fuel applications.

Detection of disease specific biomarkers is of great importance in diagnosis and treatment of diseases. Modern bioanalytical techniques, such as liquid chromatography with mass spectrometry (LC-MS), have the ability to identify biomarkers, but their cost and scalability are two main drawbacks. Enzyme-linked immunosorbent assay (ELISA) is another potential tool, but it works best for proteins, rather than peptide biomarkers. Recently, microfluidics has emerged as a promising technique due to its small fluid volume consumption, rapidness, low fabrication cost, portability and versatility. Therefore, it shows prominent potential in the analysis of disease specific biomarkers. In this thesis, microfluidic systems that integrate monolith columns for preconcentration and on-chip labeling are developed to analyze several protein biomarkers. I have successfully fabricated cyclic olefin copolymer (COC) microfluidic devices with standard micromachining techniques. Monoliths are prepared in situ in microchannels via photopolymerization, and the physical properties of monoliths are optimized by varying the composition and concentration of monomers to achieve better flow and extraction. On-chip labeling of protein biomarkers is achieved by driving solution through the monolith using voltage and incubating fluorescent dye with protein retained in the monolith. Subsequently, the labeled proteins are eluted by applying voltages to reservoirs on the microdevice and detected by laser-induced fluorescence. Finally, automation of on-chip preconcentration and labeling is successfully demonstrated.

Tracer gas surveys are a powerful means of assessing air quantity in underground mine ventilation circuits.  The execution of a tracer gas style ventilation survey allows for the direct measurement of air quantity in locations where this information is otherwise unattainable.  Such instances include inaccessible regions of the mine or locations of irregular flow.  However, this method of completing a mine ventilation survey is an underused tool in the industry.  This is largely due to the amount of training required to analyze survey results. As well, the survey is relatively slow because of the time required to perform analysis of results and the time required to allow for the total elution of tracer compounds from the ventilation circuit before subsequent tracer releases can be made.  These limitations can be mitigated with the development of a protocol for a novel tracer gas which can be readily implemented with existing technology.  Enhanced tracer gas techniques will significantly improve the flexibility of ventilation surveys.  The most powerful means to improve tracer gas techniques applied to mine ventilation surveys is to alter existing protocols into a method that can be readily applied where tracer surveys already take place. One effective method of enhancing existing tracer gas survey protocols is to simply add a second tracer gas that can be detected on a gas chromatograph -- electron capture detector (GC-ECD) using the same method as with the existing industry standard tracer, sulfur hexafluoride (SF6).  Novel tracer gases that have been successfully implemented in the past called for complex analysis methods requiring special equipment, or were designed for inactive workings.  Experimentation with perfluoromethylcyclohexane (PMCH) and SF6 allowed for ideal chromatographic results.  PMCH is a favorable selection for a novel tracer to work in tandem with SF6 due to its chemical stability, similar physical properties and detection limits to SF6, and its ability to be applied and integrated into an existing system.  Additionally, PMCH has been successfully utilized in other large-scale tracer gas studies. Introduction of a novel tracer gas will make great strides in improving the versatility of underground tracer gas ventilation surveys, but further improvement to the tracer gas technique can be made in simplifying individual steps.  One such step which would benefit from improvement is in sampling.  Solid phase microextraction (SPME) is a sampling method that is designed for rapid sampling at low concentrations which provides precise results with minimal training.  A SPME extracting phase ideal for trace analysis of mine gases was selected and a GC-ECD protocol was established.  The protocol for fiber selection and method optimization when performing trace analysis with SPME is described in detail in this thesis.  Furthermore, the impact of sampling with SPME under varying turbulent conditions is explored, and the ability of SPME to sample multiple trace analytes simultaneously is observed. / Master of Science