Described in many studies as dangerous for the environment and potentially carcinogenic for humans, Chlorinated Paraffins (CPs) are easily widespread due to their substantial production and use in different products. Previous studies reported the presence of CPs in different plastic polymers. However, the impact of recycled content in plastic materials on the CPs levels hasn’t particularly been considered. Recycling plastics is becoming essential but the accumulative potential of pollutants, such as CPs, need investigations. The presence of CPs in both virgin and mixed recycled and virgin plastics was studied. Plastic pellets and plastic pieces from products made of three polymer types:Poly(methyl 2-methylpropenoate) (PMMA), Thermoplastic Rubber (TPR) and Thermoplastic Polyurethane (TPU) were analysed. A solid-liquid extraction assisted by ultrasonication was performed, followed by cleanup using silica. CPs in plastic extracts were analysed by Gas Chromatography Orbitrap High Resolution Mass Spectroscopy (GC-Orbitrap-HRMS). Because of the high volatility characteristic of long chain Chlorinated Paraffins (LCCPs), only short chain and medium chain Chlorinated Paraffins (SCCPs and MCCPs ) have been studied in this project. Interesting variations in the presence of SCCPs and MCCPs have been observed from one polymer type to another. In the results, we show that MCCPs were less frequently detected compared to SCCPs. A higher detection frequency of CPs was observed for samples containing recycled plastics. The results indicate that CPs are present in plastic polymers (TPU, PMMA and TPR) and that the content of recycled material has a direct impact on the levels of SCCPs and MCCPs.

Yes / Distinguishing animal fats from plant oils in archaeological residues is not straightforward. Characteristic plant sterols, such as ¿-sitosterol, are often missing in archaeological samples and specific biomarkers do not exist for most plant fats. Identification is usually based on a range of characteristics such as fatty acid ratios, all of which indicate that a plant oil may be present, none of which uniquely distinguish plant oils from other fats. Degradation and dissolution during burial alter fatty acid ratios and remove short chain fatty acids, resulting in degraded plant oils with similar fatty acid profiles to other degraded fats. Compound specific stable isotope analysis of ¿13C18:0 and ¿13C16:0, carried out by gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS), has provided a means of distinguishing fish oils, dairy fats, ruminant and non-ruminant adipose fats but plant oils are rarely included in these analyses. For modern plant oils where C18:1 is abundant, ¿13C18:1 and ¿13C16:0 are usually measured. These results cannot be compared with archaeological data or other modern reference fats where ¿13C18:0 and ¿13C16:0 are measured, as C18:0 and C18:1 are formed by different processes resulting in different isotopic values. Eight samples of six modern plant oils were saponified releasing sufficient C18:0 to measure the isotopic values, which were plotted against ¿13C16:0. The isotopic values for these oils, with one exception, formed a tight cluster between ruminant and non-ruminant animal fats. This result complicates the interpretation of mixed fatty residues in geographical areas where both animal fats and plant oils were in use. / AHRC

No / A systematic identification of the degradation products of hydroxypropyl methylcellulose phthalate (HPMCP) during hot melt extrusion (HME) has been performed. A reverse phase HPLC method was developed for the extrudates of both hydroxypropyl methylcellulose acetate succinate (HPMCAS) and HPMCP polymers to quantify their thermal hydrolytic products: acetic acid (AA), succinic acid (SA) for HPMCAS and phthalic acid (PA) for HPMCP, without hydrolysing the polymers in strong alkaline solutions. The polymers were extruded in the temperature range of 160-190 degrees C at different screw rotation speeds and hydrolytic impurities were analysed. Investigation of extruded HPMCP showed an additional thermal degradation product, who is structural elucidation revealed to be phthalic anhydride (PAH). Moreover, two environmental analytical impurities, dimethyl phthalate and methyl benzoate formed in situ were recorded on GC-MS and their origin was found to be associated with PAH derivatization. Using the experimental data gathered during this study, a degradation mechanism for HPMCP is proposed.

M. Tech. (Biotechnology) Vaal University of Technology / One of the major problems encountered in qualitative and quantitative determination of residual pesticides by gas chromatography is the matrix effects. Matrix components have a considerable effect on the way analysis is conducted and the quality of results obtained, introducing problems such as inaccurate quantification, low analyte delectability and reporting of false positive or even false negative results. It was aimed to develop and validate a suitable method for counteracting the matrix effects so as to improve the detection and quantification of selected organochlorine pesticide residues from real water samples. The real water samples used were sampled from three points along the Jukskei River catchment area in Gauteng, South Africa for a period of 7 months from January to July 201 0 so as to create a representative sample. An automated solid phase extraction (SPE) method coupled to Gas ChromatographyMass Spectrometry (GC-MS) method for the analysis of 20 selected organochlorine pesticides was developed and validated for the purposes of studying the matrix effects. The analytical method showed a significant degree of validity when tested against parameters such as linearity, repeatability and sensitivity. Endosulphan beta, 4,4' Dichlorodiphenyldichloroethane, and Heptachlor-epoxide had the broadest linear calibration ranges of 1 ppm- 0.0156 ppm. Benzene hexachloride (BHC) delta and Lindane had the lowest statistical limits of detection of 0.018 ppm. Statistical hypothesis testing indicated that there was significant linearity in all selected organochlorine calibration curves. Four different reversed sorbent phases, including LC18, SC18- E and Strata-X (styrene divinyl benzene) were tested for organochlorine retention efficiency. The LC-18 200 mg cartridge proved to be the most robust and effective sorbent phase as it produced better recoveries varying from 90-130% for most analytes. A breakthrough volume of 100 ml for the LC-18 200 mg cartridge was determined using an optimum matrix load curve. It was then concluded that the method developed was suitable for further research towards the influence of the matrix on selective determination of the selected organochlorine pesticides. Four different calibration methods, namely matrix-free external standard, matrixmatched external standard, matrix-free internal standard and matrix-matched internal standard were applied to test the efficiency of computing recoveries. All calibration curves for the 20 organochlorine pesticides showed significant linearity > 0.99 when plotted on both Chemstation and Excel. The calibration methods were tested on three different matrices composed of a high sample matrix (synthetic matrix), a low sample matrix (real sample matrix) and a no sample matrix (ultrapure water). Statistical hypothesis testing led to the decision that there are significant differences between the mean recoveries of the three water sample matrices and also that the differences in the mean recoveries of the three sample matrices are independent of the both the two calibration techniques (internal standard and external standard) and calibration types (matrix-matched and matrix-free) applied. This led to the overall conclusion that the matrix effects have an overwhelming influence on the selective determination of the selected organochlorine pesticides.

<p>Ricin je prirodni protein, toksin koji spada među najpristupačnije i najsmrtonosnije otrove. Nalazi se u biljci Ricinus (Ricinus communis), sa najvećim sadržajem u semenu (1-5 %). Ricin se smatra potencijalnim bioterorističkim oružjem i prema riziku za ljudsko zdravlje svrstan je u B kategoriju biolo&scaron;kog oružja. U novije vreme kori&scaron;ćen je za konstruisanje imunotoksina protiv tumorskih ćelija u terapiji maligniteta. Dokumentovana su mnoga trovanja ricinom, kako zadesna, tako i samoubilačka i ubilačka. U tu svrhu koristilo se intaktno seme ricinusa ili ekstrahovani ricin. Osim ricina, u semenu ricinusa je prisutan toksični alkaloid ricinin u količini 0.3-0.8 %. Ricinus je jedini poznati prirodni izvor ricinina, koji se ko-ekstrahuje sa ricinom iz semena biljke. Ricinin se jednostavno detektuje u kliničkim uzoracima metodom tečne hromatografije i masene spektrometrije i, s obzirom na komplikovanu identifikaciju ricina u biolo&scaron;kim uzorcima, smatra se biomarkerom za intoksikaciju ricinusom, odnosno ricinom. Osnovni ciljevi ovog istraživanja su da se uz pomoć HS-GC metode i patohistolo&scaron;kom&nbsp; analizom dokaže prisustvo ricinina u krvi laboratorijskih pacova u odnosu na vremenski interval koji je protekao od oralne aplikacije suspenzije do vremena žtvovanja, da se odredi distribucija i koncentracija ricinina u organima laboratorijskih pacova u različitim vremenima žrtvovanja, kao i da se utvrdi da li postoji značajna razlika u razvoju patomorfolo&scaron;kih promena na organima laboratorijskih pacova u različitim vremenima žrtvovanja. Istraživanje je bilo otvoreno, randomizirano i prospektivnog tipa. Laboratorijski pacovi su u istom vremenu oralno tretirani suspenzijom koja je sadržaja subletalnu koncentraciju ricina. Nakon žrtvovanja u precizno definisanim vremenskim intervalima uzeti su uzorci krvi i unutra&scaron;njih organa radi daljih analiza. Odgovarajući uzorci su analizirani metodom HC-GS u cilju određivanja koncentracije i distribucije ricinina, kao pouzdanog markera trovanja ricinom, u krvi i unutra&scaron;njim organima. Takođe je izvr&scaron;ena patohistolo&scaron;ka analiza uzoraka tkiva unutra&scaron;njih organa u cilju utvrđivanja promena izazvanim delovanjem ricina u odnosu na vreme proteklo od aplikacije suspenzije. Dobijeni rezultati su obrađeni odgovarajućim statističkim metodama. Rezultati istraživanja omogućavaju standardizaciju postupaka odabira reprezentativnih uzoraka prilikom sumnje na trovanje ricinusom i metode dokazivanja akutnog trovanja. Na taj način može se pouzdano i efikasno dokazati trovanje ricinusom.</p> / <p>Ricin is a naturally occurring protein, a toxin which belongs to the category of the most accessible and the most lethal poisons. It is obtained from the castor oil plant ( Ricinus communis), whose seeds contain its highest content (1-5%). Ricin is also thought to be a potential weapon of bioterrorism and taking into account the risk for human health, it is classified as a biological weapon category B. Lately it has been used for the construction of the immunotoxins against tumor cells in the therapy of malignant diseases. Numerous poisonings using ricin have been documented, not only accidental poisoning, but also in case of suicides and homicides. In those cases, intact ricin seeds or extracted ricin were used. Apart from ricin, castor oil plants also contain a toxic alkaloid ricinine (0.3-0.8%). Castor oil plants are the only known natural source of ricinine, which is co-extracted with ricin from the seeds of this plant. Ricinine is simply detected in clinical samples by using the method of liquid chromatography and mass spectrometry. Taking into account a complicated identification of ricin in biological samples, it is considered to be a biomarker for the intoxication by castor oil plant, or ricin itself. The main aim of this research is to use the HS-GC method and pathohistological analysis in proving the existence of ricinine in the blood of experimental rats in relation to the time interval between the oral application of solution of castor seeds in water and the time of sacrificing, to determine the distribution and concentration of ricinine in the organs of experimental rats, as well as to establish whether there was a significant difference in the development of pathomorphological changes on the organs of experimental rats at various points of sacrificing. The research was open, randomised and prospective. Experimental rats were simultaneously orally tested by the solution which contained sublethal concentration of ricin. After sacrificing, blood samples were taken from inner organs in specifically defined intervals of time and used for further analysis. The appropriate samples were analysed by HC-GS method in order to determine the concentration and distribution of ricinine as a reliable marker of ricin poisoning in blood and inner organs. Also, pathohistological analysis of the samples of inner organ tissues was made with the purpose of establishing the changes caused by the effects of ricinine in relation to time which passed from the application of the solution. The obtained results were processed by appropriate statistical methods. The results of this research allow for the standardisation of the actions in selecting the representative samples in case there is a possibility of ricin poisoning and the method of proving the acute poisoning. Following these steps, ricin poisoning can be proved in a reliable and an efficient way.</p>

The disposal of waste from agricultural activities has been recognised as a source of environmental contamination by endocrine disrupting chemicals (EDCs). The New Zealand dairy industry produces a large volume of dairy farm effluent, which contains EDCs in the form of estrogens. Most of this dairy farm effluent is applied onto the land for disposal. Groundwater and soil contamination by estrogens following waste application on the land have been reported overseas, but our understanding of the processes and factors governing the fate of estrogens in the soil is poor. Therefore the main goal of the present study was to better understand the fate and transport of estrogens, in particular 17β-estradiol (E2) and estrone (E1) in soil. In order to quantify E1 and E2 in drainage water and soil samples, chemical analysis by gas-chromatography mass-spectrometry (GC-MS) was carried out. This included sample extraction, sample clean-up through silica gel and gel permeation chromatography, and sample extract derivatisation prior to analysis. In order to develop a reliable method to extract estrogens from soil, research was conducted to optimise E1 and E2 extraction conditions by adjusting the number of sonication and shaking events, as well as the volume and type of solvent. Among five solvents and solvent mixtures tested, the best recovery on spiked and aged soil was obtained using an isopropanol/water (1:1) mix. A microcosm experiment was carried out to determine the dissipation rates of E2 and E1, at 8°C and at field capacity, in the Templeton soil sampled at two different depths (5-10 cm and 30-35 cm). The dissipation rates decreased with time and half-life values of 0.6-0.8 d for E1 and 0.3-0.4 d for E2 were found for the two depths studied. A field transport experiment was also carried out in winter, over three months, by applying dairy farm effluent spiked with estrogens onto undisturbed Templeton soil lysimeters (50 cm in diameter and 70 cm deep). The hormones were applied in dairy farm effluent at 120 mg m⁻² for E2 and 137 mg m⁻² for E1. The results of the transport experiment showed that in the presence of preferential/macropore flow pathways 0.3-0.7% of E2 and 8-13% of E1 was recovered in the leachate at the bottom of the lysimeters after 3 months, and 1-7% of the recovered E2 and 3-54% of the recovered E1 was leached within 2 days of application. These results suggest that leaching of estrogens via preferential/macropore flow pathways is the greatest concern for groundwater contamination. In the absence of preferential/macropore flow pathways, a significant amount (> 99.94%) of both hormones dissipated in the top 70 cm of soil, due to sorption and rapid biodegradation. Surprisingly, in all cases, estrogen breakthrough occurred before that of an inert tracer (bromide). This could not be explained by the advection-dispersion transport of estrogens, nor by their presence as antecedent concentrations in the soil. It was therefore suggested that colloidal enhanced transport of estrogens was responsible for the earlier breakthrough of estrogens and caused the leaching of a fraction of the applied estrogens to a soil depth of 70 cm. A two-phase model, adapted from a state-space mixing cell model, was built to describe the observed estrogen transport processes under transient flow. The model takes into account 3 transport processes namely, advection-dispersion, preferential/macropore flow and colloidal enhanced transport. This model was able to successfully describe the estrogen transport observed from the lysimeters.

Environmental and health aspects of road materials have been discussed for a long time, mostly regarding bitumen and bitumen fumes. However, just a few studies on other types of road materials have been reported. In this doctoral study, two types of materials, asphalt release agents and bituminous sealants, were investigated with regard to chemical characterization and emission profiles. Besides conventional test methods, solid-phase microextraction (SPME) technique was applied for emissions profiles screening and quantitative analysis. General description of main characteristics of asphalt release agents and bituminous sealants is given, and a comprehensive state-of-the-art on SPME technique is presented, especially on methodologies for analyzing mono- and polycyclic aromatic hydrocarbons (MAHs and PAHs) in different sample matrices. In the experimental study, chemical characterization of the two material types was performed using conventional methods, including fourier transform infrared spectroscopy - attenuated total reflectance (FTIR-ATR), gel permeation chromatography (GPC), mass spectrometry (MS) and gas chromatography – mass spectrometry (GC-MS). General patterns regarding functional groups and molecular weight distribution were studied. In the case of asphalt release agents, more detailed information on chemical compositions, especially the contents of MAHs and PAHs, was obtained. General information on emission proneness of asphalt release agents was obtained using thermogravimetric analysis (TGA) and MS. Using headspace(HS)-SPME and GC-MS, emission profiles of asphalt release agents were characterized at different temperatures, whereas the profiles of bituminous sealants were obtained solely at room temperature. The results presented were used for ranking the materials with regard to degree of total emission as well as emission of hazardous substances. The applicability of HS-SPME for quantitative analysis of MAHs in asphalt release agents and emulsion-based bituminous sealants was investigated. The use of a surrogate sample matrix was concerned, and experimental parameters influencing the HS-SPME procedure, such as equilibration and extraction time, as well as effects of sample amount and matrices, were studied. The methods were evaluated with regard to detection limit, accuracy as well as precision. Different calibration approaches including external calibration, internal calibration and standard addition were investigated. The determination of MAHs in asphalt release agents and emulsion-based bituminous sealants using HS-SPME-GC-MS was conducted. / QC 20100913

Chromatography and extraction techniques, and also chemiluminescence have been utilized to develop new rapid and informative tools in the evaluation of long-term properties and environmental effects of polymeric materials. Methods were developed for classification of materials and for early and rapid degradation detection. Degradable polyethylene films were classified on the basis of their incorporated prooxidant systems using chromatographic fingerprinting of carboxylic acids, the dominating type of degradation product. The fingerprints were also shown to be useful for prediction of the degradation states and evaluation of the degradation mechanisms. Classification and prediction models were obtained by Multivariate Data Analysis, where the diacids were grouped according to both their type of prooxidant system and their state of degradation. The use of total luminescence intensity (TLI) measurements was also investigated as a means of classifying films and for the early detection of degradation. Comparisons were carried out with common techniques, e.g. FTIR and DSC, after both thermal and UV oxidation. TLI gave an earlier detection of degradation and was more sensitive than carbonyl index and crystallinity measurements to relative differences in degradation between the materials. It furthermore offered complementary information regarding changes in activation energies during the course of the degradation. The results were compared with the chromatographic fingerprints. A new way to evaluate the low temperature long-term stabilisation efficiency of antioxidants was investigated. A prooxidant was used to obtain catalytic oxidation, instead of using thermal acceleration, to evaluate the stabilisation efficiency of antioxidants at low temperatures but still during reasonably short aging times. Comparisons were made between polypropylene films stabilised with primary antioxidants (Irganox 1076, Irganox 1010 and α-tocopherol) with and without the prooxidant manganese stearate at different temperatures. The relative efficiencies of the antioxidants obtained under prooxidant acceleration test correlated better than thermal acceleration test with the results of a long-term low temperature test. Additives in plastic packaging materials may affect the environment after migration from the packaging to e.g. their contents, especially if they consist of organic aqueous solutions or oils. The use of Solid-Phase Microextraction (SPME) for the specific task of extraction from an organic aqueous solution such as a simulated food or pharmaceutical solution consisting of 10 vol-% ethanol in water was investigated. Methods were developed and evaluated for extraction both with direct sampling and with headspace sampling. If the extraction method and temperature were selected to suit the concentration levels of the analytes, it was possible to quantify several degradation products simultaneously. Comparisons made with Solid Phase Extraction showed the advantage of SPME for this purpose. / QC 20100929

Natural resins have been in use for a long time and for manifold purposes resulting in a long and complex terminological history. The investigation of this history has so far been based on the connection between nomenclature and chemical composition. Because resin chemistry and the botanical classification of source plants are connected as well, the investigation of natural resins can be enhanced by adding taxonomy as an additional dimension, providing a more complex and complete picture of resin chemistry and resin use. The Vigani Cabinet, a collection of 300-year-old pharmaceutical and chemical materials owned by Queens’ College, Cambridge (UK), allows doing just that. A wide range of historical literature provides information about contemporary terminology, botanical and geographical origin, manufacture, trade and properties of resinous materials from the 18th century. This contemporary context is a particular feature of the Cabinet, which allows adding a historical dimension to the correlations between terminology, chemical composition and taxonomy. The dissertation thesis presented here provides an investigation of 17 botanical, 80 reference materials and samples from 24 natural resins from the Vigani Cabinet, studying these complex correlations and changes over time. The analytical method employed in this study was gas chromatography-mass spectrometry (GC-MS) with and without methylation with trimethylsulfoniumhydroxide. This technique provided detailed molecular compositions of the studied materials. Analysed botanical samples are taken from Pinaceae, Cupressaceae and Pistacia resins, commerical references from Araucariaceae, Copaifera, Fabaceae, Myroxylon and Burseraceae. Additionally, the soluble fraction of Baltic amber was analysed. Materials from the Vigani Cabinet analysed in this work were labelled as "turpentines", "pix burgundica", "sandaracha", "copaiba", "balsamum peruvianum and tolutanum", "mastiche", "anime", "copal", "elemi", "tacamahaca" and "succinum". Historical nomenclature of natural resins has not always been unequivocally associated with a botanical origin. The availability of natural resins changed throughout the centuries. Lack of knowledge, in particular about resins from over-seas, or adulterations resulting from changing harvesting methods, led to changes in trade names or variations in the composition of products traded under the same name. Generic names were used for resins with similar properties but different botanical (and geographical) origin. The thesis shows that a chemotaxonomic reference system is suitable for the identification of unknown resinous materials, and a number of new insights into the nomenclature of natural resins from the 17th and 18th century is obtained. The study of historical literature contributed in a significant way to the historico-cultural and archeometric research of the samples from the Vigani Cabinet and of natural resins in general and provided a basis for the interpretation of the chemical data from the Vigani samples. / Naturharze werden schon lange für sehr unterschiedliche Zwecke verwendet. Dies hat zu einer oft komplizierten Terminologie geführt, deren Untersuchung sich bisher auf den Zusammenhang zwischen dem Namen des Harzes und seiner chemischer Zusammensetzung stützte. Letztere ist aber auch mit der botanischer Herkunft und damit der Biochemie der Stammpflanze verknüpft, weshalb man chemotaxonomische Aspekte für die systematische Untersuchung von Naturharzen als zusätzliche Variablen nutzen kann. Dadurch erhält man, wie die gezeigt werden soll, ein vollständigeres und komplexeres Bild der Chemie und Nutzung von Naturharzen. Die hier präsentierte Untersuchung beschäftigt sich mit dem Vigani-Kabinett, einer 300 Jahre alten pharmazeutischen Materialiensammlung, die sich im Queens‘ College, Cambridge (UK), befindet. In der Literatur des ausgehenden 17. und des 18. Jahrhunderts finden sich zahlreiche Informationen zu Terminologie, botanischer und geographischer Herkunft, Verarbeitung, Handel und Eigenschaften von Naturharzen. Dadurch wird die historische Dimension des oben beschriebenen Zusammenhangs zwischen Terminologie, chemischer Zusammensetzung und Taxonomie erfahrbar. In der Arbeit werden 17 botanische Proben, 80 moderne Referenzmaterialien und 24 Proben aus dem Vigani-Kabinett im Hinblick auf diese Zusammenhänge und Veränderungen untersucht.Die chemischen Analysen wurden mit gekoppelter Gaschromatografie-Massenspektrometrie mit und ohne Methylierung mit Trimethylsulfoniumhydroxid durchgeführt. Damit konnte die molekulare Zusammensetzung der Proben detailliert untersucht werden. Die untersuchten botanischen Proben stammten von Pinaceae, Cupressaceae und Pistaciaharzen, kommerzielle Referenzen von Araucariaceae, Copaifera, Fabaceae, Myroxylon und Burseraceaeharzen. Zusätzlich wurde noch die lösliche Fraktion von Baltischem Bernstein untersucht. Die untersuchten Proben aus dem Vigani-Kabinett waren sowohl englisch als auch Latein mit "turpentines", "pix burgundica", "sandaracha", "copaiba", "mastiche", "anime", "copal", "elemi", "tacamahaca", "balsamum peruvianum and tolutanum" und "succinum" beschriftet. Zusammenfassend lässt sich sagen, dass die historische Nomenklatur von Naturharzen nicht immer eindeutig mit ihrem botanischen Ursprung verknüpft war. Zusätzlich veränderte sich die Erhältlichkeit der Harze im Laufe der Jahrhunderte. Durch fehlendes Wissen, insbesondere für Materialien und Pflanzen aus Übersee, oder Verfälschungen aufgrund von veränderten Fördermethoden veränderten sich die Handelsnamen dieser Materialien oder die Zusammensetzung von Materialien, die unter demselben Namen gehandelt wurden. Harze mit ähnlichen Eigenschaften aber unterschiedlichen botanischen (und geographischen) Ursprungs trugen generische Namen. Die Arbeit zeigt jedoch, dass ein chemotaxonomisches Bezugssystem die Identifizierung von unbekannten Harzen ermöglicht, und zeigt eine Reihe neuer Erkenntnisse über die Nomenklatur von Naturharzen des 17. und 18. Jahrhunderts. Die Untersuchung historischer Quellen trug dabei sehr zur Erhellung des historisch-kulturellen und archeometrischen Hintergrundes und zur Interpretation der chemischen Daten der Vigani-Proben bei.

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