Microorganisms are monitored as a key indicator of water quality. Measurement of “total viable organisms” (TVO, similar to “heterotrophic plate count”, HPC) is used to indicate the general hygiene level of the water, and is often used to assess water treatment. Automated, instrumental TVO detection in water samples using an enzyme reaction method shortens the detection time compared to conventional HPC methods. A method that can detect TVO without interference in water samples by monitoring enzyme activities through fluorescent signals in small custom sample cells was developed. In this method, fluorogenic substrates were cleaved by specific enzymes to make fluorescent products, which then partitioned into a non-polar siloxane polymer film on the bottom of the sample cell. A miniature spectrometer monitored fluorescence in the polymer to give a present/absent result for bacteria. There is no interference from sample color and turbidity because the light never passes through the sample matrix. Eight substrates that can be converted by six different enzymes were characterized. These had fluorescent products coupled to glucose, glucuronic acid, galactose, phosphate, sulfate and alanine. Four different products were produced, providing detection of some enzymes simultaneously but independently, depending on the substrates chosen. Candidate fluorescent products were first tested with different siloxane polymers and two dimethyl-siloxane polymers were identified to detect all the products separately. Fifteen laboratory bacteria strains (including E. coli, Klebsiella pneumonia, and Pseudomonas aeruginosa) were added individually to a substrate solution containing minimal nutrients and incubated. All bacteria types were successfully detected by at least one substrate, with most detected by several substrates. Sterility of water samples from lake water, treated lake water and tap water were tested with those eight substrates separately or in combination. The lake water had the highest bacteria level and included coliforms and possibly E. coli. Treated lake water and tap water were E. coli and coliforms free, and were safe for drinking. Treated lake water had higher TVO levels than tap water, indicating a lower hygiene level. The results of combined substrate tests matched the corresponding single substrate tests, suggesting specific bacteria strains can be distinguished in a single test. / Thesis (Master, Chemistry) -- Queen's University, 2013-08-01 18:03:54.111

There is a need for chemical sensors for monitoring volatile organic compounds (VOCs) in air. Acute and chronic inhalation of toxic VOCs can cause adverse health effects in humans, so monitoring these analytes is important for ensuring that their concentrations are maintained below maximum permissible levels. Chemical sensors using polydimethylsiloxane (PDMS) to extract VOCs with partial selectivity, coupled with label-free optical detection methods based on refractive index, can overcome the limitations of conventional VOC detection methods. A variety of tunable and high refractive index PDMS materials were developed by incorporating a range of titanium and zirconium concentrations (2.5 – 30 mol % and 2.5 – 15 mol %, respectively) using a simple sol-gel synthesis and by incorporating a range of titanium concentrations (2.5 – 10 mol %) into naphthyl-functionalized PDMS. These materials ranged in refractive index from 1.4023 ± 0.0002 to 1.5663 ± 0.0001 at 635 nm and 1.3942 ± 0.0003 to 1.5510 ± 0.0007 at 1550 nm. The ability to use tunable refractive index PDMS films to differentiate between m-xylene and cyclohexane was demonstrated by monitoring changes in refractive index and thickness following absorption of these analytes using a refractometer at 1550 nm. The sensitivity of the refractive index response to an analyte using a particular PDMS film was dependent upon the difference between the refractive index of the analyte and film, as well as the film-air partition coefficient of the analyte. The detection limits for m-xylene and cyclohexane were 81 ppm and 4940 ppm, respectively, using PDMS-titanium-oxo nanocomposites with 5 and 10 mol % Ti, respectively. A simple planar waveguide sensor with an input grating coupler was developed to monitor changes in refractive index of the cladding through shifts in peak resonance wavelength. Using high refractive index PDMS materials as the waveguide core, we monitored changes in refractive index arising from absorption of VOCs into the grating. Here, the sensitivity of the waveguide response was dependent upon the difference in refractive index of the analyte and polymer, as well as the film-air partition coefficient of the analyte. The detection limits for m-xylene and cyclohexane were 1980 ppm and 18000 ppm, respectively. / Thesis (Master, Chemistry) -- Queen's University, 2013-08-24 11:45:57.642

The use of laser desorption as a sample introduction method for solid phase microextraction (SPME) has been investigated in this research project. Three different types of analytical instruments, mass spectrometry (MS), ion mobility spectrometry (IMS) and gas chromatography (GC) were employed as detectors. The coupling of laser desorption SPME to these three instruments was constructed and described in here. <br /><br /> Solid phase microextraction/surface enhanced laser desorption ionization fibers (SPME/SELDI) were developed and have been coupled to two IMS devices. SPME/SELDI combines sampling, sample preparation and sample introduction with the ionization and desorption of the analytes. Other than being the extraction phase for the SPME fiber, the electro-conductive polymer coatings can facilitate the ionization process without the involvement of a matrix assisted laser desorption/ionization (MALDI) matrix. The performance of the SPME coatings and the experimental parameters for laser desorption SPME were investigated with the SPME/SELDI IMS devices. The new SPME/SELDI-IMS 400B device has a faster data acquisition system and a more powerful data analysis program. The optimum laser operation parameters were 250 <em>&mu;J</em> laser energy and 20 <em>Hz</em> repetition rate. Three new SPME coatings, polypyrrole (PPY), polythiophene (PTH) and polyaniline (PAN) were developed and evaluated by an IMS and a GC. The PPY coating was found to have the best performance and was used in most of the experiments. The characteristics of the PPY and the PTH SPME/SELDI fiber were then assessed with both IMS and MS. Good linearity could be observed between the fiber surface area and the signal intensity, and between the concentration and the signal intensities. <br /><br /> The ionization mechanism of poly(ethylene glycol) 400 (PEG) was studied with the SPME/SELDI-IMS 400B device. It was found that the potassiated ions and sodiated ions were both present in the ion mobility spectra. The results obtained with quadrupole time-of-flight (QTOF) MS confirmed the presence of both potassiated and sodiated ions. This result suggested that cationization is the main ionization process when polymers are directly ionized from the PPY coated silica surface. Four PEGs with different average molecular weights and poly(propylene glycol) 400 were also tested with this SPME/SELDI device. The differences between the ion mobility spectra of these polymers could be used for the fast identification of synthetic polymers. <br /><br /> The SPME/SELDI fibers were then coupled to QTOF MS and hybrid quadrupole linear ion trap (QqLIT) MS, respectively. Improved sensitivity could be achieved with QqLIT MS, as the modified AP MALDI source facilitated the ion transmission. The application of method for analysis of urine sample and the bovine serum albumin (BSA) digest were demonstrated with both PPY and PTH fibers. The LOD for leucine enkephalin in urine was determined to be 40 <em>fmol &mu;L^-1</em> with PTH coated fiber; and the LOD for the BSA digest was 2 <em>fmol &mu;L^-1</em> obtained with both PTH and PPY fibers. <br /><br /> A new multiplexed SPME/AP MALDI plate was designed and evaluated on the same QqLIT MS to improve the throughput, and the performance of this technique. The experimental parameters were optimized to obtain a significant improvement in performance. The incorporation of diluted matrix to the extraction solution improved the absolute signal and S/N ratio by 104X and 32X, respectively. The incorporation of reflection geometry for the laser illumination improved the S/N ratio by more than two orders of magnitude. The fully optimized high throughput SPME/AP MALDI configuration generated detection limit improvements on the order of 1000-7500X those achieved prior to these modifications. This system presents a possible alternative for qualitative proteomics and drug screening. <br /><br /> Laser desorption SPME as a sample introduction method for the fast analysis of non-volatile synthetic polymers was also demonstrated here. The coupling of laser desorption SPME to GC/FID and GC/MS was performed, and the advantage of laser desorption over traditional thermal desorption was demonstrated in this research. Laser desorption PEG 400 was observed more effcient than thermal desorption. Good separation was obtained even with a 1-m or 2-m column. These results demonstrate the potential of laser desorption SPME as a sample introduction method for the fast GC analysis of non-volatile compounds such as synthetic polymers.

The spread of tetracyclines through agricultural systems is causing the present bacteria to develop antibiotic resistance. The spread of this bacteria, as well as the tetracycline antibiotics in the environment is dangerous because these antibiotics pose health hazards for humans. The overuse of antibiotics, which are added to livestock feed, results in the antibiotics being released into the environment via animal feces. In this research, we have attempted to design an analytical method to isolate antibiotics from agricultural wastes with subsequent detection using liquid chromatography and mass spectrometry (LC-MS). The antibiotics investigated in this study were tetracycline, chlortetracycline, and oxytetracycline. The analytical procedure involves mixing the agricultural samples with an organic solvent, such as methanol, which solubilizes these antibiotics. Next, samples are centrifuged to remove solid particulates. A polymeric weak cation cartridge was used to concentrate and separate the antibiotics from the unwanted organic chemical compounds found in the samples. The antibiotics were released with methanol with small amounts of acid and then detected and quantified using LC-MS and high performance liquid chromatography with a photodiode array detector (HPLC-PDA).

Des peptides antigéniques sont présentés à la surface des cellules cancéreuses ou infectées par un virus pour être reconnus par des cellules du système immunitaire. Cette reconnaissance déclenche alors une réponse immunitaire spécifique contre les cellules présentatrices ciblées. L'objectif de ce projet est de stimuler cette réponse immunitaire afin qu'elle soit un moyen thérapeutique pour détruire spécifiquement les cellules cancéreuses ou infectées. Toutefois, les peptides antigéniques ne peuvent pas être administrés tels quels, du fait de leur pauvre stabilité en milieu biologique. Il est donc nécessaire de les modifier afin qu’ils soient plus résistants. Le défi de ce projet est de synthétiser des peptidomimes bio-résistants, capables de reproduire la même réponse immunitaire que celle du peptide antigénique naturel. / Abstract

The feasibility of using oriented polymer technology in the design and manufacture of mechanical power transmission belts has been investigated. Working from an initial selection of polymers a die-drawing technique for orienting the polymers was devised, and the static and dynamic mechanical properties of the oriented polymers were investigated. These results indicated that PP, PBT, PPS and PEEK were suitable for further research. Of these 4 materials PBT was selected as the most appropriate material for belt manufacture based on cost, processability (drawing temperature, natural draw ratio) and limitations of laboratory equipment. A technique based on free-tensile drawing combined with simultaneous rotational motion was designed and used to manufacture oriented PBT flat belts from cylindrical injection moulded preforms. The technique used a tensile machine with two pulley-clamps, a fitted heated chamber and an electric motor to provide rotational motion to the belt during drawing. Two types of oriented PBT flat belts with different cross sections were produced successfully, termed 'thick' and 'thin'. These belts were tested on a purpose-built rig comprising two equal diameter pulleys, one driven by an electric motor and the other connected to a generator to provide load. The belt life and power transmission performance was investigated at various conditions of speed, transmitted torque and tension, and the results indicated that despite their smaller cross section 'thin' flat belts demonstrated up to 3 times longer life. However life was only 100hours, which was very low compared with conventional flat belts that last for many thousands of hours at higher speeds and much greater power transmission capacity. Synchronous belts were then produced through the same manufacturing method used for flat belts. This aspect of the research concentrated on the initial pitch design and size, i.e. the timing. Initially a rectangular tooth profile was selected for its simplicity in terms of manufacture. The produced belts exhibited high pitch length variation as well as deformed teeth and were not usable for synchronous power transmission. An extra timing feature was included to control orientation; reducing the pitch length variation enabling consistent tooth production. It was observed that the areas between the extra timing feature and the tooth edges did not orient completely with some regions remaining undrawn. Finite Element Analysis (FEA) was used to predict the drawing behaviour of different shapes and dimensions of the timing features. The results suggested that a 4mm wide and 7mm long slot provided the highest possible extension and the minimum non-oriented regions on the groove. Whilst, the thickness and width of the drawn belt timing features showed differences to the FEA predictions, manufactured synchronous belts based on that design had much better controlled dimensions and the lowest achieved pitch length variation ( ±1%), compared to initial attempts. It is concluded that oriented polymers have the potential to be used in power transmission belts since they offer higher stiffness, tensile strength and creep resistance compared with isotropic polymers that are currently used in commercially available belts such as thermoplastic polyurethane (TPU) and polyvinyl chloride (PVC). The main disadvantages were the lack of dimensional stability and number of cycle to failure.

The development of improved sequencing technologies hasenabled the field of genomics to evolve. Handling andsequencing of large numbers of samples require an increasedlevel of automation in order to obtain high throughput andconsistent quality. Improved performance has lead to thesequencing of numerous microbial genomes and a few genomes fromhigher eukaryotes and the benefits of comparing sequences bothwithin and between species are now becoming apparent. Thisthesis describes both the development of automated purificationmethods for DNA, mainly sequencing products, and a comparativesequencing project. The initially developed purification technique is dedicatedto single stranded DNA containing vector specific sequences,exemplified by sequencing products. Specific capture probescoupled to paramagnetic beads together with stabilizing modularprobes hybridize to the single stranded target. After washing,the purified DNA can be released using water. When sequencingproducts are purified they can be directly loaded onto acapillary sequencer after elution. Since this approach isspecific it can be applied to multiplex sequencing products.Different probe sets are used for each sequencing product andthe purifications are performed iteratively. The second purification approach, which can be applied to anumber of different targets, involves biotinylated PCR productsor sequencing products that are captured using streptavidinbeads. This has been described previously, buthere theinteraction between streptavidin and biotin can be disruptedwithout denaturing the streptavidin, enabling the re-use of thebeads. The relatively mild elution conditions also enable therelease of sensitive biotinylated molecules. Another project described in this thesis is the comparativesequencing of the 40 kbcagpathogenicity island (PAI) in fourHelicobacter pyloristrains. The results included thediscovery of a novel gene, present in approximately half of theSwedish strains tested. In addition, one of the strainscontained a major rearrangement dividing thecagPAI into two parts. Further, information about thevariability of different genes could be obtained. Keywords:DNA sequencing, DNA purification, automation,solid-phase, streptavidin, biotin, modular probes,Helicobacter pylori,cagPAI. / <p>NR 20140805</p>

Catalysis plays a key role in chemical conversions by making them faster and more selective. Despite its widespread use and decades of academic and industrial research, limited catalyst selectivity and stability still call for major improvements in catalyst performance to meet the demands of a sustainable society. Phosphine ligands are ubiquitous in transition metal chemistry and lead to extremely reactive and versatile homogeneous catalysts. Fast development of tailor-made catalysts and catalyst recovery are key issues in (asymmetric) homogeneous catalysis. Therefore libraries of ligands have to be synthesised and screened in an efficient way, which could be facilitated by Solid Phase Synthesis (SPS). Currently, most polymer bound ligands are anchored to the support after the synthesis in solution. However, the main advantages of synthesising the ligands directly on the polymeric support are not only easy catalyst recycling and product separation, but also the ease of purification during the synthesis steps, namely by simple washing and filtration. The use of SPS is very efficient for high throughput synthesis and screening of ligand libraries, however applications of SPS towards libraries of phosphorus ligands are rare, because the synthetic methodologies are still lacking. Here we present the development of methodologies towards novel immobilised bis(phosphine) ligands synthesised on polystyrene and JandaJel™ resin. By performing the synthesis steps on a solid support, the advantages of SPS are fully utilised. Successful routes have been developed towards immobilised secondary phosphine-boranes, which were versatile synthons to prepare a variety of new polymer-supported (C-chiral) bis(phosphine) ligands. These ligands were then tested for their catalytic activity in rhodium catalysed hydrogenation reactions.

4 Abstract Estrogens are considered to belong to chemicals that negatively affect the endocrine system, even if present at very low concentrations. They are discharged into environment as a result of an increasing application of drugs etc. This work is focused on the separation and quantification of five estrogens, namely estrone (E1), 17β-estradiol (βE2), 17α-estradiol (αE2), 17α-ethynylestradiol (EE2) and estriol (E3) in natural water samples by HPLC-UV method. The chromatographic system consisted of a C18 stationary phase (SunFire® C18, 150 x 4.6 mm, octadecyl bounded to silica gel, particle size 5 µm) and binary mobile phase of acetonitrile/water in various ratios in isocratic separation mode. The effect of acetonitrile content in the mobile phase and flow rate of the mobile phase on retention and separation parameters was tested. Under the optimized separation conditions (acetonitrile/water 40/60 (v/v), 1.3 ml/min), all the compounds were baseline resolved and eluted within 15 min. These experimental conditions were applied to the calibration measurements which were carried out within the concentration range from 0.001 to 1 mg/ml. Limits of detection (LOD) and limits of quantification (LOQ) for the individual estrogens and their mixture (standards dissolved in methanol) were determinated. The detection...

<p>QCR 20161026</p>