Thesis (MTech. degree in Environmental management.)-Tshwane University of Technology, 2008. / Aims to determine the presence and levels of DDT and its metabolites in human breast milk samples using supercritical fluid extraction and liquid-liquid extraction techniques.

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Anyžinis lofantas (Agastache foeniculum (Pursh) Kuntze) – tai vaistinis, prieskoninis daugiametis augalas. Vienas iš notrelinių šeimos dekoratyvus, daugiametis žolinis augalas, kilęs iš Šiaurės Amerikos. Lietuvoje kol kas dar mažai paplitęs. Auginamas botanikos soduose ir darželiuose, vertinamas kaip labai kvapnus, medingas ir vaistinis augalas. Anyžinis lofantas dirvai mažai reiklus, turi gerai išvystytą šaknų sistemą, todėl nebijo sausros. Geriau auga derlingesnėje žemėje, nepiktžolėtose priesmėlio arba lengvo priemolio dirvose, atviroje, saulėtoje vietoje. Žydi nuo birželio vidurio iki spalio mėnesio. Žiedai – ryškiai violetiniai arba melsvi. Agastache foeniculum paruoštas VDU Kauno Botanikos sode, 2010 metais masinio žydėjimo metu. Sausoje žaliavoje yra 1,71-2,10 % eterinio aliejaus, kurio svarbiausios dalys yra D-limonenas ir estragolis. Nupjauta žolė džiovinama paskleista plonu sluoksniu gerai vėdinamoje arba 35°C temperatūros patalpoje. Išdžiovinta žolė atskiriama nuo stambesnių stiebų ir laikoma sudėta į medžiaginius maišus. Tinkamai išdžiovinta žolė yra 12 - 14 % drėgnumo. Džiovinimas – vienas svarbiausių etapų, kuris labiausiai įtakoja galutinę vaistinės žaliavos kokybę. Šiame darbe – buvo identifikuoti Agastache foeniculum eterinių aliejų komponentai: D- limonenas, estragolis, kariofilenas. Vaistinio anyžinio lofanto eterinių aliejų ekstraktai ruošti naudojant superkritinio skysčio CO2 ekstrakciją. Jų analizė atlikta dujų chromatografu– masių spektrometrijos... [toliau žr. visą tekstą] / Blue giant hyssop (Agastache foeniculum (Pursh Kuntze) is medicinal perennial plant. This ornamental plant is native to North America. In Lithuania is not yet widely spread. It is cultivated in botanical gardens and is valuable because is a fragrant, melliferous medicinal plant. Blue giant hyssop is not strict for soil and has a well developed system of the roots, so it is resistant to drought. This plant prefers a good soil and sunny places. It blooms from the middle of June to October. The flowers are violet or royal-blue. Agastache foeniculum raw material was prepared in Kaunas botanical garden of VMU during flowering season in 2010. In dry raw material is about 1.71 – 2.10  of essential oils, the basic components are D-limonene and estragol. The grass after cutting was spread in a thin layer in well ventilated room or in the room at 35 C temperature. The dried grass was separated from stems and stored in huckaback bags. The well dried grass has about of 12-14  moisture. The drying is one of the most important periods which influence the final quality of drug raw material. In this work the components of essential oils of Agastache foeniculum have been identified. The extracts of volatile oils of Agastache foeniculum were prepared by supercritical CO2 extraction. After the analysis the relative quantities of essential oils components as well as composition have been evaluated by gas chromatography-mass spectrometry detector. Investigations have showed that the... [to full text]

Sites contaminated with polyaromatic hydrocarbons (PAHs) pose serious health and safety risks to the surrounding environment due to their toxicity, persistence and accumulation in the environment. Because certain members of this class have been demonstrated to be both carcinogenic and mutagenic, PAHs are considered as environmental priority pollutants (US EPA). The studies in this thesis provide an efficient, economical and environmentally benign technique for the remediation of PAH contaminated soil/sediment by means of PAH mobilization with surfactant followed with a catalytic hydrogenation in supercritical carbon dioxide (scCO2). / Catalytic hydrogenation of naphthalene, acenaphthylene, ancenaphthene, anthracene, phenanthrene, chrysene and benzo[a]pyrene over alumina supported palladium (5% Pd0/gammaAl2O3) commercial catalyst were investigated in either a batch reaction mode or a continuous reaction system in H2-scCO2 (∼5% v/v). The hydrocarbon compounds were efficiently reduced to their corresponding fully saturated polycyclic hydrocarbon homologs with mild conditions of temperature (90°C) and pressure (60 psi H2 or 3000 psi H2-scCO2). The bacterial reverse mutation assay demonstrated that both the fully and partially hydrogenated products of chrysene and benzo[a]pyrene were devoid of mutagenic activity. / A laboratory study was conducted on the surfactant-assisted mobilization of PAH compounds combined with reagent regeneration and detoxification steps to generate innocuous products. Five minutes of ultrasonication of field contaminated soil with a 3% (w/v) surfactant suspension mobilized appreciable quantities of all PAH compounds. Formulating the Brij 98 surfactant in 0.1 M phosphate buffer (pH 8.0) mobilized the largest quantities of PAH compounds and the recovery of surfactant (>90%) but soil residues exceeded permissible maxima for five- and six-ring analytes. Five successive washes were required to reduce the residual fraction to permissible levels. The mobilized PAH compounds were then detoxified at line by catalytic hydrogenation in a 5% H2-scCO2 (v/v) atmosphere. / New palladium hydrogenation catalysts were fabricated in the laboratory with specific processes on various supports. The hydrogenation of phenanthrene and benzo[a]pyrene in a fixed bed micro reactor demonstrated that the catalyst that was fabricated from organosoluble precursor loaded on aluminum oxide (2.5% Pd0/gammaAl2O3) was four times more efficient than the commercial catalyst that was used for PAH hydrogenations.

Extraction of hydrocarbons from an Athabasca oil sand slurry were conducted using supercritical carbon dioxide (SC-CO2). The oil sand was slurried to a 1:1 ratio with water and experiments were conducted using a laboratory-scale batch supercritical fluid extraction (SFE) system. Preliminary tests revealed the importance of mixing rate on hydrocarbon yields. A 2^3 factorial experiment was then conducted to test the effect of temperature, pressure, and modifier (toluene) addition on hydrocarbon extraction yield. When toluene was absent, hydrocarbon extraction yields were greater at the high temperature (60°C); however, when toluene was present, the combination of low temperature (31°C) and high pressure (24.1MPa) provided greater extraction yields. The experiment that produced the highest cumulative hydrocarbon extraction yield was analyzed by GC-FID for product-quality. Two composite samples and one time series sample revealed a carbon distribution range of the extract centering on C25, corresponding to the light gas oil range as classified in petroleum fractions. / Environmental Science

This study investigates the extraction of hydrocarbons from oil sand using supercritical carbon dioxide (SC CO2). Experiments were carried out on three different types of oil sands. After some preliminary experiments, the feasibility of extracting hydrocarbons from oil sands by SC CO2 was confirmed and three experimental factors (pressure, temperature and mixing rate) were identified for further study. A two to the three factorial design was used to determine the significance of each factor and the significance of the interaction of the factors on the extraction efficiency. The extraction efficiency was calculated from Dean-Stark extraction analysis and was compared to the extraction efficiency based on gravimetric analysis. The results show that the extraction efficiency increased with pressure at a constant temperature. The effect of temperature on extraction efficiency is complex. The highest extraction efficiency was obtained at the high pressure (24.1MPa), high temperature (60C) and a mixing rate of 250rpm. / Environmental Science

Drug re-engineering is an effective method for engineering existing products in alternative dosage forms and with enhanced pharmacokinetics. Insulin for the management of diabetic symptoms is an ideal candidate for re-engineering. Current subcutaneous therapy results in low patient compliance and is ineffective in meeting the physiological need for post-prandial insulin. Implementation of dose titration for more efficient blood-glucose management is also inconvenient and uncomfortable. Inhaled insulin is presented as a superior alternative to current therapy. The lungs offer excellent access to the circulatory system. Aerosols suspended in inspired air may deposit on lung epithelia and be available for systemic absorption. To evade the defense mechanism of the human respiratory tract, particle sizes have traditionally been minimized to achieve necessary aerosol performance. Recent developments indicate that more efficient performance augmentation may also be achieved by decreasing the bulk density of powders and modifying surface characteristics. Light and fluffy powders with rough surfaces experience much higher drag forces within an airstream. The Atomized Rapid Injection for Solvent Extraction (ARISE) process is a unique precipitation platform devised by incorporating a rapid injection technique for energetic solution delivery into supercritical fluid (SCF) media to effect recovery of previously dissolved pharmaceutical compounds. The quasi-instantaneous delivery of solutions alleviates the drawbacks of the use of capillary nozzles or micro-orifices, gradual elution and mixing controlled precipitation kinetics in existing SCF precipitation techniques. Most importantly, the energetic release of solution into SCF media effects supersaturation over a much larger spatial volume and promotes the homogeneous precipitation of low bulk density powders. ARISE processed insulin powders displayed characteristics that were highly influenced by anti-solvent conditions and powders of different qualities were obtained as a function of anti-solvent pressures. At lower anti-solvent pressures, powders of narrow particle size distribution were achieved, an indication of homogeneous supersaturation levels within processing. Span, the index of size distribution was as low as 0.991. At higher anti-solvent pressures, supersaturation rates were increased while mixing efficiencies decreased, resulting in powders of wider size distribution, and powder bulk densities as low as 0.01 g/ml. Low bulk density insulin displayed in-vitro respirable fractions as high as 78%.

Thesis (Ph. D.)--Carleton University, 2001. / Includes bibliographical references. Also available in electronic format on the Internet.

Thesis (doctoral)--Lund University, 1997. / Added t.p. with thesis statement inserted.