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Amphetamine-type stimulants (ATS) constitute a group of drugs where the parent compound is amphetamine or methamphetamine. Many ATS are classified as Schedule 8 controlled compounds due to their addictive properties and their detrimental impacts on society. Over fifty percent of clandestine laboratories detected in Australia in 2017-18 manufactured ATS or their precursors. The manufacture of these drugs can liberate hazardous volatile compounds into the air and, as most clandestine laboratories are located in residential areas, the manufacture of ATS poses a significant risk to law enforcement personnel as well as the general public. There is currently a lack of technology capable of extracting and detecting ATS and their precursors from a gas sample. This research investigated the application of a novel gas-to-liquid extraction interface in tandem with CYBERNOSE® biosensors for the extraction and detection of volatile ATS and related compounds. A method was developed that evaluated the effectiveness and efficiency of this recently developed gas-to-liquid extraction interface that utilised an open capillary bed with a liquid capture agent to extract target ATS and their precursors. Five of the seven target compounds selected could be extracted from gas samples, with extraction efficiencies typically ranging between one and five percent based on theoretical starting concentrations. It was established that the extraction efficiency was correlated to the target compound’s volatility and the effectiveness of the gas generation and sampling system to keep the compounds in the gas phase. Four different CYBERNOSE® biosensors were tested to characterise their response to the seven target compounds. It was discovered that, due to the instability and sensitivity of the biosensors, previous detection parameters used for preliminary screening of the biosensors were unsuitable and an instrument-specific method was developed. Under the optimised conditions, the biosensors demonstrated high responses to four of the seven target compounds. When the gas-to-liquid interface was combined with the CYBERNOSE® biosensors, two of the five compounds that were able to be extracted from a gas sample could be differentiated from control samples. It was concluded that the gas-to-liquid interface could be used as a new method for extracting volatile ATS and related compounds from collected air samples. It was also concluded that, due to the instability and lack of reproducibility of the current generation of CYBERNOSE® biosensors, further research is required before their use could be envisaged for ATS detection.

Biological material (fluids or tissues) whether from the victim or suspect is often collected as forensic evidence, and methods to obtain and analyze the DNA found in that material have been well established. The type of body fluid (i.e. blood, saliva, semen, vaginal secretions, and menstrual blood) from which the DNA originated is also of interest, and messenger RNA typing provides a specific and sensitive means of body fluid identification. In order for mRNA profiling to be utilized in routine forensic casework, RNA of sufficient quantity and quality must be obtained from biological fluid stains and the methods used for RNA analysis must be fully compatible with current DNA analysis methodologies. Several DNA/RNA co-extraction methods were evaluated based on the quantity and quality of DNA and RNA recovered and were also compared to standard non-co-extraction methods. The two most promising methods, the in-house developed NCFS co-extraction and the commercially available AllPrep DNA/RNA Mini kit, were then optimized by improving nucleic acid recovery and consistency of CE (capillary electrophoresis) detection results. The sensitivity of the two methods was also evaluated, and DNA and RNA profiles could be obtained for the lowest amount of blood (0.2 µL) and saliva and semen (1 µL) tested. Both extraction methods were found to be acceptable for use with forensic samples, and the ability to obtain full DNA profiles was not hindered by the co-extraction of RNA. It is generally believed that RNA is less stable than DNA which may prevent its use in forensic casework. However, the degradation rates of DNA and RNA in the same biological fluid stain have not been directly compared. To determine the relative stability of DNA and RNA, the optimized NCFS co-extraction protocol was used to isolate DNA and RNA from iv environmentally compromised stains. Dried blood, saliva, and semen stains and vaginal secretions swabs were incubated at set temperatures and outside for up to 1 year. Even at 56°C, DNA and RNA were both stable out to 1 year in the blood and semen stains, out to 3 months (DNA) and 1 year (RNA) in the saliva stains, and out to 6 months (DNA) and 3 months (RNA) in the vaginal secretions swabs. The recoverability of both nucleic acids was reduced when the samples were exposed to increased humidity, sunlight, and rain. In general, DNA and RNA stability was found to be similar with a loss in ability to obtain a DNA or RNA profile occurring at the same time point; however, there were instances where RNA body fluid markers were detected when a poor/no DNA profile was obtained, indicating that RNA in dried stains is sufficiently stable for mRNA body fluid typing to be used in forensic casework.

Polycyclic aromatic hydrocarbons (PAH) are important environmental pollutants originating from a wide variety of natural and anthropogenic sources. Because many of them are highly suspect as etiological agents in human cancer, chemical analysis of PAH is of great environmental and toxicological importance. Current methodology for PAH follows the classical pattern of sample preparation and chromatographic analysis. Sample preparation preconcentrates PAH, simplifies matrix composition, and facilitates analytical resolution in the chromatographic column. Among the several approaches that exist to pre-concentrate PAH from water samples, the Environmental Protection Agency (EPA) recommends the use of solid-phase extraction (SPE). High-performance liquid chromatography (HPLC) and gas chromatographymass spectrometry (GC-MS) are the basis for standard PAH identification and determination. Ultraviolet (UV) absorption and room temperature fluorescence detection are both widely used in HPLC, but the specificity of these detectors is modest. Since PAH identification is solely based on retention times, unambiguous PAH identification requires complete chromatographic resolution of sample components. When HPLC is applied to "unfamiliar" samples, the EPA recommends that a supporting analytical technique such as GC-MS be applied to verify compound identification and to check peak-purity HPLC fractions. Independent of the volume of extracted water, the approximate time required to separate and determine the sixteen "priority pollutants" (EPA-PAH) via HPLC is approximately 60min. If additional GC-MS analysis is required for unambiguous PAH determination, the total analysis time will reach 2-3 hours per sample. If the concentrations of target species are found to lie outside the detector’s response range, the sample must be diluted and the process repeated. These are important considerations iv when routine analysis of numerous samples is contemplated. Parent PAH are relatively inert and need metabolic activation to express their carcinogenicity. By virtue of the rich heterogeneous distribution of metabolic products they produce, PAH provide a full spectrum of the complexity associated with understanding the initial phase of carcinogenesis. PAH metabolites include a variety of products such as expoxides, hydroxyl aromatics, quinines, dihydrodiols, dioepoxides, tetrols and water soluble conjugates. During the past decades tremendous efforts have been made to develop bio-analytical techniques that possess the selectivity and sensitivity for the problem at hand. Depending on the complexity of the sample and the relative concentrations of the targeted metabolites, a combination of sample preparation techniques is often necessary to reach the limits of detection of the instrumental method of analysis. The numerous preparation steps open ample opportunity to metabolite loss and collection of inaccurate data. Separation of metabolites has been accomplished via HPLC, capillary electrophoresis (CE) and GC-MS. Unfortunately, the existence of chemically related metabolic products with virtually identical fragmentation patterns often challenges the specificity of these techniques. This dissertation presents significant improvements in various fronts. Its first original component – which we have named solid-phase nano-extraction (SPNE) - deals with the use of gold nanoparticles (Au NPs) as extracting material for PAH. The advantages of SPNE are demonstrated for the analysis of PAH in water samples via both HPLC1 and Laser-Excited TimeResolved Shpol’skii Spectroscopy (LETRSS).2 The same concept is then extended to the analysis of monohydroxy-PAH in urine samples via SPE- HPLC3 and In-Capillary SPNE-CE.4 The second original component of this dissertation describes the application of Shpol’skii Spectroscopy to the analysis of polar PAH metabolites. The outstanding selectivity and v sensitivity for the direct analysis of PAH at trace concentration levels has made Shpol’skii spectroscopy a leading technique in environmental analysis.5 Unfortunately, the requirement of a specific guest-host combination - typically a non-polar PAH dissolved in an n-alkane - has hindered its widespread application to the field of analytical chemistry. This dissertation takes the first steps in removing this limitation demonstrating its feasibility for the analysis of polar benzo[a]pyrene metabolites in alcohol matrixes.6

Starch residue samples from two Australian sweet potato varieties (Beauregard and Northern Star) and two Indonesian sweet potato varieties (Bis192 and Bis183), and commercial sample of sweet potato starch residue, were studied for their pectins. Pectins were extracted using 0.1M HCl, 0.05M NaOH, 0.1M HCl/0.75%SHMP, and 0.05M NaOH/0.75% SHMP. Hydrolysis of residual starch in the cell wall of sweet potato using heat stable α-amylase and amyloglucosidase was employed prior to pectin extraction to eliminate starch contamination. Pectins were characterised for yield, moisture, ash, galacturonic acid content (GA), degree of esterification (DE), neutral sugars content and molecular weight (MW). Selected pectins were also characterised for their dispersion and gel properties. Pectin with the highest yield was compared to commercial low methoxyl pectin (GRINSTED®YF 450) for its application in milk pudding. The pectin characteristics are dependent on variety and extraction process; however, the extraction methods were dominant. Yields were between 7 and 30 % of the cell wall. Ash varied from 2.9 to 6.8%. NaOH/SHMP extraction gave higher yields and ash contents. Moisture was between 5.5 and 6.7. GA varied from 27 to 80% with the highest found in Bis192 extracted using NaOH/SHMP. DE varied between traceable and 57%. HCl extraction gave higher DE, while NaOH/SHMP caused demethylation. Neutral sugars varied from 10 to 25% where galactose was the predominant sugar, followed by arabinose, rhamnose, glucose and xylose. Pectin MW was very heterogeneous. HCl extraction gave higher MW than the others. Dispersion of sweet potato pectins displayed shear-thinning. Consistency coefficient (K) increased, while flow behaviour index (n) decreased with increasing pectin concentration. HCl-extracted pectins formed stiff sugar-gels at concentrations higher than 2%. The optimum Ca2+ concentration for NaOH/SHMP-extracted pectin gels was 20 mg/g pectin. Pectin with the highest yield and stiffness (Norther Star extracted using NaOH containing SHMP) was used for milk pudding preparation. This pudding had comparable texture to pudding prepared from commercial low methoxyl citrus pectin (GRINSTED®YF 450). Overall, this study demonstrated that pectin from sweet potato starch residue is mainly low methoxyl pectin with possible chemical structure of rhamnogalacturonan I (RGI) that has potential for food applications.

Ligand-modified micellar-enhanced ultrafiltration (LM-MEUF) is a membrane based separation method for removal of metal ions from aqueous solutions. An amphilic ligand which will selectively complex the target ion is solubilized in surfactant micelles and added to the waste stream. Semi-equilibrium dialysis (SED), ultrafiltration (UF) and spectrophotometric titration methods have been used to investigate the properties and effectiveness of a commercially available ligand, Kelex 100, for removal of toxic metals ions with LM-MEUF using several different surfactant solutions. The use of alkylated thiourea ligands for removal of mercury was also studied.

The mass transfer and hydraulic characteristics of a 2.54 cm diameter sieve tray extraction column operating with supercritical and liquid solvents were investigated. Supercritical and liquid carbon dioxide were used to extract alcohols from water at pressures of 81.6 to 102.0 atm and temperatures of 25°C to 40°C. Toluene was employed to separate acetone from water at 25°C and 1 atmosphere in the same apparatus so that conventional and supercritical extraction could be compared. A mechanistic mass transfer model was developed to predict the overall efficiency of a sieve tray column operating with supercritical and liquid solvents. The model was based on liquid extraction theory and predicted efficiencies within ±25% of the experimental values. The input parameters required for the model simulation were the operating, geometric, and physical properties of the system. The investigation included the measurement of mass transfer efficiency, phase equilibria, throughput capacity, column end effects, drop diameter, and operational holdup data. Average experimental overall efficiencies were 48% for the supercritical CO₂/isopropanol/water system, 63% for the supercritical CO₂/ethanol/water system, 46% for the liquid CO₂/ isopropanol/water system, and 14% for the toluene/acetone/water system. These values were adjusted to account for column end effects which represented about 30% of the total mass transfer. Throughput capacities for the supercritical systems in the sieve tray column were over 100% greater than for the toluene/acetone/water system. The present research represents the first step towards the development of an algorithm for the design of extraction columns operating with supercritical solvents, and it demonstrates that supercritical separations can be modeled mechanistically based on liquid extraction principles. Although results from this investigation indicate that supercritical fluid extraction permits high throughput capacities and provides relatively high mass transfer efficiencies compared with conventional extraction, final evaluations must await studies in larger equipment and with a broader range of system properties