Naphthenic acids (NA) are a highly complex mixture of aliphatic carboxylic acids that may contain multiple rings and unsaturated double bonds, and are a subset of the naphthenic acid fraction components (NAFC), which can contain heteroatoms, unsaturations, and aromatic structures. Mono-carboxylated NAs can be classically represented by CnH2n+zO2 where z is a negative integer representing the hydrogen deficiency. NAs and NAFCs are components of the acid extractable organics (AEO) frequently associated with increased toxicity and observed at elevated concentrations in oil sands process waters (OSPW). Numerous chromatographic and mass spectrometry techniques have recently emerged to probe the composition and concentrations of these components. This thesis reports the use of a capillary hollow fiber polydimethylsiloxane (PDMS) membrane mounted on a probe interface that can be immersed directly into an aqueous sample. A methanol acceptor phase passing through the lumen transports analyte to an electrospray ionization source and a triple quadrupole mass spectrometer. This technique, termed condensed phase membrane introduction mass spectrometry (CP-MIMS), allows for rapid screening of m/z profiles and on-line quantification of NAs in complex samples within minutes. This thesis reports parametric studies of several model carboxylic acids and a standard naphthenic acid mixture (Merichem) involving the effect of sample pH on membrane transport and acceptor phase pH on ionization enhancement. Several quantitative strategies are explored including the use of an internal standard in the acceptor phase to correct for ionization suppression and variations in instrument sensitivity, and the use of selected ion monitoring (SIM) experiments to increase analytical sensitivity and potentially target specific NA isomer classes for quantitation. Analytical performance measures such as the linear dynamic range (1-2300 ppb [NA]T as Merichem), sensitivity (~1 ppb [NA]T as Merichem detection limit), precision (~20 %RSD for replicates of a single OSPW) and accuracy are reported. Quantitative results for various OSPW samples in the ppb to ppm range are reported as equivalents of several surrogates, including 1-pyrenebutyric acid (PyBA), Merichem, and a large-volume extract of northern Alberta OSPWs. The variety of quantitation strategies allows results to be compared with several other published methods. CP-MIMS results for three mid-range northern Alberta OSPWs are compared to analysis by Environment Canada with an average -21% bias. Results for five archived OSPWs spanning a wider concentration are compared to data from AXYS Analytical, with an average -49% bias. Applications of CP-MIMS as an in-situ monitor of removal efficiencies of NAs on adsorbents and real-time mass profile changes are also presented, along with some interpretation of the resulting high-resolution kinetic data to obtain decay constants. Using the targeted SIM method, adsorption decay can be followed in real-time for various isomer classes within the Merichem mixture, and kinetic data extracted to obtain decay constants for each. CP-MIMS is also used to characterize adsorption behavior for two activated biochars, including % removals for various loadings of each when added to stirred Merichem solutions. Preliminary multi-loading experiments are conducted with one biochar, and the ability of CP-MIMS to characterize adsorbent behavior by constructing adsorption isotherm plots is demonstrated. / Graduate

Over the last few decades, membrane introduction mass spectrometry (MIMS) has been established as a robust tool for the on-line continuous monitoring of trace gases and volatile organic compounds. However, the range of amenable anlaytes has been limited by the need for molecules to pervaporate into a gaseous acceptor phase, or high vacuum environment of a mass spectrometer. This thesis expands the range of amenable analytes for MIMS to include larger, less volatile molecules (e.g., 200 to 500 Da), such as pharmaceuticals, persistent organic pollutants, and small biomolecules. This was achieved through the use of a liquid|membrane|liquid interface. We distinguish the technique from conventional MIMS, which uses a gaseous acceptor phase, by inserting the prefix ‘condensed phase’ to emphasize the use of a solvent acceptor phase – thus yielding CP-MIMS. An initial flow-cell interface with a methanol acceptor phase was characterized, yielding detection limits for model analytes in pptr to ppb, and analyte response times from 1-10 minutes. The flow cell interface was miniaturized into an immersion style CP-MIMS probe (~2 cm), which allowed for analysis of smaller volume samples and improved membrane washing capabilities. Comparable detection limits were observed for the immersion probe, however, it was noticed that significant analyte depletion was observed for samples under 2 mL. In addition, each of the developed membrane interfaces were observed to suffer from ionization suppression effects from complex samples when paired with ESI. Several strategies for mitigating ionization suppression using CP-MIMS are presented, including the use of a continuously infused internal standard present within the acceptor solvent. The developed CP-MIMS system was challenged with the analysis of naphthenic acids (a complex mixture of aliphatic carboxylic acids) directly in contaminated real-world samples. The method used negative ESI to rapidly screen and mass profile aqueous samples for naphthenic acids (as [M-H]-), with sample duty cycles ~20 min. However, it was found that Negative ESI did not differentiate hydroxylated and carboxylated analytes, and both species contributed signal to the total naphthenic acid concentration. To increase method specificity for carboxylic acids, barium ion chemistry was used in conjunction with positive ion tandem mass spectrometry. Common product ions were used to quantify carboxylated analytes, while a qualifier ion was used to confirm the functionality. The increased selectivity afforded by the barium ion chemistry was at the cost of a modest increase in detection limits. CP-MIMS has been established as a technique capable of the direct analysis of real-world samples, and shows promise as a rapid screening method for amenable environmental contaminants and/or biomolecules. / Graduate / 0486 / 0485 / kyle.duncan@viu.ca

In the last decade there has been increasing research interest in the value of bio-sourced materials from lignocellulosic biomass. The dissolution of cellulose by ionic liquids (ILs) has led to investigations including the dissolution of cellulose, lignin, and complete biomass samples and the in situ processing of cellulose. Rapid quantitative measurement of cellulose dissolution in ILs is difficult. In this work, Fourier transform infrared spectroscopy (FTIR) spectra of cellulose dissolved in 1-ethyl-3-methylimidazolium acetate ([emim][OAc]) were subjected to partial least squares (PLS) regression to model dissolved cellulose content. PLS regression was used due to the ease in developing predictive models with this technique in addition to linear regression being ineffectual for modeling when applied to potentially thousands of variables. Applying a normalization data treatment, before regression, generated a model that estimated cellulose content within 0.533 wt%. The methods described provided the basis for a rapid methodology to determine dissolved cellulose content. Development of rapid and facile screening techniques to determine the effectiveness of various ILs as solvents for cellulose or lignin will aid in the development of lignocellulosic based bioproducts. In this work, optical microscopy with and without the use of cross-polarized lenses, was used to monitor cellulose and lignin dissolution in two imidazolium-based and two phosphonium-based ILs as well as n,n-dimethylacetamide/lithium chloride (DMAc/LiCl), demonstrating that this technique could be applied more broadly than solely for ILs. The described optical microscopy methodology was more rapid and sensitive than more traditional techniques, such as visual inspection. The viscosity of [emim][OAc] (162 cP) is 100 times that of water at 20°C and could inhibit its use as a solvent for cellulose. There is a need for simple, low-cost and environmentally benign methods to reduce the viscosity of ILs to aid in cellulose dissolution. In this work, 4 wt% cellulose dissolved in [emim][OAc] was subjected to 50 psi CO2 and 20 psi N2, as a control environment, at both 50°C and 75°C. After 24 hours a nearly 2-fold increase in dissolved cellulose over the N2 control was demonstrated through the application of a 50 psi CO2 environment for cellulose dissolution in [emim][OAc] at 50°C. / Thesis (Master, Chemical Engineering) -- Queen's University, 2011-05-25 22:58:17.744

Depuis 2007, la réglementation sur le cadre du dépistage en France évolue et se montre favorable à la création d’expérimentations de dépistage communautaire. Cette recherche propose une analyse psychosociale des expériences de dépistage dans le cadre de deux protocoles expérimentaux: ANRS Com’Test et ANRS DragTest. Les objectifs principaux des protocoles sont (1) l’étude de la faisabilité d’un dépistage rapide du VIH effectué par des acteurs communautaires non médicaux (association de lutte contre le sida Aides), auprès des hommes ayant des rapports sexuels avec des hommes, en utilisant les tests rapides d’orientation diagnostique et le counselling motivationnel (ANRS Com’Test), et (2) l’évaluation de la non infériorité de cette proposition en comparaison avec une offre classique (ANRS DragTest).L’objectif de cette étude est de comprendre les significations attribuées aux expériences vécues à partir d’une lecture ternaire (sujet-objet-contexte) et d’une articulation entre vécu et représentations sociales. La recherche s’appuie sur une méthodologie qualitative incluant d’une part une analyse longitudinale de l’expérience des acteurs associatifs, et d’autre part une analyse transversale du vécu des personnes dépistées. La triangulation des matériaux de recueil et des méthodes d’analyse apporte un double regard sur les données. En effet, les résultats montrent à la fois la mobilisation des univers de références communs, et l’implication de l’expérience vécue dans la construction et la communication de l’expérience. / Since 2007, regulation on the part of the screening in France evolves and is favourable to the creation of community screening experiments. From a psychosocial perspective, this study analyzes screening experiences in two experimental protocols’ context: ANRS Com’Test and ANRS DragTest. The main objectives of the protocols are (1) to study the feasibility of a rapid HIV testing performed by non-medical community actors (association against Aids AIDES) among men who have sex with men, using rapid testing policy diagnostic and motivational counselling (ANRS Com'Test), and (2) to evaluate the non-inferiority of the proposal in comparison with a conventional supply (ANRS DragTest).The purpose of this study is to understand the lived experience’s meaning from a ternary reading (subject-object-context) and a link between experience and social representations. Research is based on a qualitative methodology, both including a longitudinal analysis of community actors involved, and also a cross-sectional analysis of those screened’ lived experiences. Triangulation of material collection and analytical methods brings a dual perspective on the data. Analyzes are showing both the mobilization of common references universes, and the involvement of lived experience in the construction and communication of experience.

Introduction International guidelines endorse the screening of patients for human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV) and Chlamydia trachomatis before assisted reproductive techniques (ART). At present no such guidelines exists in South Africa. At the Reproductive and Endocrine Unit (referred to as “the Unit”) of Steve Biko Academic Hospital, all patients with unknown HIV status are counselled and a blood sample is collected during the initial visit for automated laboratory based HIV screening. These HIV results are not available before semen samples are processed. Furthermore, patients are not screened for HBV, HCV and Chlamydia trachomatis. Couples attending the Unit are of a low to middle socio-economic status and experience financial constraints. Moreover, automated laboratory based assays are expensive to perform. Rapid testing is a cost effective and practical method from screening patients, with a 20–30 minute result turnover time. Until screening at the Unit is improved, the possible identification of semen characteristics that could indicate HIV infection would be a useful tool. Materials and Methods The following rapid point-of-care assays were evaluated: Determine® HIV-1/2 combo test (n=100), Determine® HBsAg test (n=100), DIAQUICK HCV kit (n=74), and the DIAQUICK Chlamydia trachomatis kit (n=30). For profiling, parameters from a basic semen analysis of HIV-positive males (n=60) were compared with HIV-negative males (n=60). Information pertaining to CD4 count, antiretroviral treatment and plasma viral load of HIV-positive males were analysed. Results From all patients included in the study, 8% tested positive for HIV. The risk of a female being HIV-positive was 3.73 times higher than for males. In the pilot study to explore rapid testing for HBV and HCV, 1% and 1.4% of patients tested positive respectively. When testing for Chlamydia trachomatis 31.3% of females, but no males tested positive. Comparing semen profiles, no significant differences were found between samples from HIV positive and negative males or between HIV positive males categorised by CD4 cell count (p>0.05). For the HIV-positive group with a detectable plasma HIV viral load (>40 copies/ml), a significant difference was observed in the semen viscosity (p=0.0460). Significant differences were noted in the sperm motility (immotile sperm p=0.0456, progressive sperm p=0.0192) of patients receiving antiretroviral (ARV) therapy. Discussion and Conclusion The use of rapid testing is an acceptable and feasible option for improving current screening protocols at the Unit. The absence of definite alterations in the semen characteristics of HIV-positive men further motivates the need for a simpler, point-of-care screening protocol. The prevalence of HBV was lower than that reported in the general population of South Africa and further investigation is needed. Although the sample size was small, HCV prevalence was similar to that of the general population. One third of females tested positive for Chlamydia trachomatis. The methodology used was possibly not appropriate for males. This study highlighted the need for guidelines that address the specialised needs of ART clinics in resource-limited and developing countries with a high HIV prevalence. / Dissertation (MSc)--University of Pretoria, 2013. / gm2014 / Obstetrics and Gynaecology / unrestricted