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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
331

Development of an analytical method for the analysis of flumetsulam in soybean by HPLC-UV and LC-MS/MS

Moawad, Michael, University of Western Sydney, College of Health and Science, School of Food Science and Horticulture January 2005 (has links)
Flumetsulam … is a member of the triazolopyrimidine sulfonanilide family of herbicides. It is used for pre or post-emergence broadleaf weed control in wheat, corn, barley and soybean. It has low toxicity and is readily degradable. A HPLC-UV method for the analysis of flumetsulam with the use of a surrogate and internal standard was developed and validated for soybean. The surrogate and internal standards are diclosulam and benzoic acid respectively. A LC-ESI-MS/MS confirmation method in the positive ion mode was also developed for flumetsulam. In the solvent-solvent extraction method, flumetsulam was extracted from the soybean with MeOH and the extract partitioned with a hexane:MTBE mixture (which was discarded). In the solid phase extraction and clean up method, C-18, SAX and SCX cartridges were used. Flumetsulam was extracted from the soybean as for the solvent-solvent extraction method. The solvent-solvent extraction method was used for flumetsulam determination at fortification levels of 10, 20, 50 and 100 ng -g soybean -1. The method has average absolute recoveries of 80% (range 72 to 90%). The absolute precision of recovery is about 16% and the detection limit is 4.8 ng g-1.The solid phase extraction method was used for flumetsulam determination at fortification levels of 20, 50, and 100 ng (ng soybean )-1. The precision of recovery is about 11%. The detection limit is 7.2 ng g-1. The MRL for flumetsulam recommended by the Australian Pesticides and Veterinary Medicines Authority is 50 ng g-1 for pulses. / Doctor of Philosophy (PhD)
332

Impact of horticultural mineral oil and synthetic pesticides on arboreal and soil fauna biodiversity within citrus orchard ecosystems

Liang, Weiguang, University of Western Sydney, College of Science, Technology and Environment, School of Science, Food and Horticulture January 2002 (has links)
The results of the 3-year project successfully indicated that petroleum-derived spray oils can be used for effective control of a range of citrus pests including citrus leafminer, Asiatic citrus psyllid, chaff scale, red scale, citrus red mite. The results suggested that it should be possible, through use of horticultural and agricultural mineral oils and enhanced natural enemy activity, to reduce the number of pesticide sprays applied annually in China from 14-16 sprays to significantly fewer sprays in most regions. The results are also valuable as references for the implementation of citrus integrated pest management programs in Australia and other citrus-growing countries. However, despite extensive use of PDSOs in citrus and other crops since the late 1800s, few studies have been undertaken to determine their disruptive effects on orchard ecosystems or to compare their effects with those of synthetic pesticides, and these studies are limited in their sc / Doctor of Philosophy (PhD)
333

The Health Impact of Pesticide Exposure in a Cohort of Outdoor Workers

Beard, John Roland January 2002 (has links)
This thesis describes a study undertaken between 1992 and 2001 to explore the possible health impacts of human exposure to pesticides. The study followed the health outcomes of approximately 4000 outdoor workers over a period of up to sixty-one years. These workers comprised two subcohorts of approximately even size, one composed of agricultural workers with high insecticide exposures, and the other made up of outdoor staff from local councils in the same area with little or no occupational exposure to insecticides. Mortality and morbidity were compared between the two groups, and with the general Australian community. The study identifies significantly increased mortality among both exposed and control subjects when compared to the Australian population. The major cause of this increase was mortality from smoking related diseases. The study also identifies significant increases in mortality among exposed subjects for a number of conditions that do not appear to be the result of smoking patterns, both when compared to the control group and the Australian population. These include pancreatic cancer in some DDT exposed subjects and asthma, diabetes, and leukaemia in subjects working with more modern chemicals. There was also an increase in self reported chronic illness and asthma, and lower neuropsychological functioning scores among surviving exposed subjects when compared to controls. Diabetes was also reported more commonly by subjects reporting occupational use of herbicides.
334

Dermal and ocular exposure during the spray application of selected industrial chemicals

Lee, Su G. January 2005 (has links)
"November 2004" / Bibliography: leaves 149-179. / xxviii, 218 leaves : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / "This study addresses exposure during spraying of malathion and fenthion insecticides for fruit fly control and hexamethylene di-isocyanate (HDI)-based paint in the automotive and furniture industries. The research aims to characterize exposures and symptoms, and assess the adequacy of personal protective equipment under field conditions." --p. iii. / Thesis (Ph.D.)--University of Adelaide, Faculty of Health Sciences, Dept. of Public Health, 2005
335

Dricksvattenkvalite i enskilda vattentäkter : Landskrona kommun

Larsson, Martin January 2008 (has links)
<p>Denna rapport är en sammanställning av de 100 undersökta enskilda brunnarna i Landskrona kommun vid årsskiftet 05/06. Det utfördes analyser på mikrobiologisk-, nitrat-, nitrit- och även kemiska bekämpningsmedelspåverkan. Syftet med denna rapport är att bearbeta och presentera analysresultaten av de 100 enskilda brunnarna i Landskrona kommun och försöka dra slutsatser kring dessa. Alla analysresultaten sammanställdes i tabeller och så småningom kundes vissa slutsatser dras kring varför resultatet såg ut som det gjorde. Resultatet visade att endast åtta av de 100 brunnarna var otjänliga gällande mikrobiologisk påverkan. Denna parameter är väldigt varierande beroende mycket på yttre omständigheter men det kan ge en indikation på att brunnen inte är tillräckligt tät och därför kan ytvatten tränga in i brunnen. När det gäller nitritpåverkan blev bara en brunn otjänlig. Men när det gällde nitrat var det istället 17 % av brunnarna som visade sig vara otjänliga. Detta är ändå ett relativt bra resultat beroende på hur landskapet ser ut i Skåne med stor påverkan från enskilda avlopp, jordbruk och gödsling. Sist men inte minst analyserades kemiska bekämpningsmedel och gav ett oroande resultat. Hela 35 % av brunnarna var otjänliga pga. kemiska bekämpningsmedel. Detta resultat är inget ovanligt utan kan genom danska undersökningar bara bekräftas. Kemiska bekämpningsmedel kan sprida sig långa sträckor och inte bara vid den plats där ämnena använts eller spillts. De slutsatser som kan dras genom denna undersökning är att grävda brunnar i ytliga jordlager löper störst risk att i framtiden bli otjänliga då dessa utsetts för störst påverkan av föroreningar och ytvatten. Brunnar placerade på gårdsplan är speciellt utsatta och är starkt påverkade av både mikroorganismer och kemiska bekämpningsmedel. När det gäller kemiska bekämpningsmedel är resultaten från Landskrona liknande de från både Danmark och övriga Skåne.</p> / <p>The problem with bad drinking water in wells are a wide problem in an landscape such as Skåne. The purpose of this report is to work up all the data from the different analysis regarding drinking water quality from wells in Landskrona municipality. The parameters that were analysed were microorganisms, the content of nitrate and nitrite and also the concentration of pesticides. Many reports in the field of the subject were collected to get a good picture and a better knowledge of the different problems that lie ahead. This resulted in various conclusions but some of the conclusions was confirmed from other examinations. That wells in the ground are more exposed than wells in mountain. The concentration of pesticides were very high in many of the wells wich shows that this will be a great problem for us to deal with in the future. Examinations in both Denmark and remaining parts of Sweden also show high concentration of pesticides. This only confirm that the problem isn’t just a local here in the municipality.</p>
336

Nitrate and pesticide transport under pear production in clay and sandy soil

Cao, Weidong 06 December 1994 (has links)
Groundwater contamination on irrigated land is of concern in this nation and around the world. In order to reduce the potential of groundwater contamination by agricultural practices such as irrigation, fertilizer and pesticide application, vadose-zone monitoring and sampling are needed. The main objective of this study was to evaluate impacts of current irrigation treatments and soil structures on the migration of pollutants to groundwater. Passive CAPillary wick pan Samplers (PCAPS) and suction cups were installed in two cracking clays and one sandy soil under the pear tree root zone. PCAPS and suction cups were used to collect nitrate-nitrogen and tracer samples. Tracers were applied to track the spatial and temporal patterns of compounds that mimic nitrate-nitrogen and pesticide movement. The observed magnitude of water leaching over 3 months differed between irrigation methods and soil structures and decreased in this order: flooding over 3 months in clay soil (22.8 cm) > micro-sprinkler in clay soil (16.1 cm) > over-head sprinkler in sandy soil (4.1 cm). Leaching patterns were varied spatially; soil structures, irrigation methods, preferential flow, and high water table may have been responsible for the spatial variation of leaching. Mass recovery of all three tracers, including bromide, blue dye, and rhodamine had the same decreasing order: flooding in clay soil > micro-sprinkler in clay soil > over-head sprinkler in sandy soil. Average blue dye and rhodamine concentrations had the following order: flooding in clay soil > micro-sprinkler in clay > over-head sprinkler in sandy soil. Since blue dye and rhodamine have similar properties to some moderately adsorbed pesticides, we may infer that the risk of pesticide movement in three sites should also decrease in this order. Presumably pesticide movement in clay soil would have been more pronounced for flooding than sprinkler irrigation. On the annual/seasonal basis, the total mass of nitrate-nitrogen leaching differed between irrigation methods and soil structures and decreased in the following order: over-head sprinkler in sandy soil > flooding in clay soil > micro-sprinkler in clay soil. The annual average nitrate-nitrogen concentration observed under over-head sprinkler in sandy soil was 15 mg/l over the maximum allowed concentration level (10 mg/l) by the EPA while seasonal nitrate-nitrogen concentration was low in clay soil under current irrigation practices. Strong evidence suggested the occurrence of preferential flow in this study. Preferential flow may contribute to high water leachate, nitrate and pesticide migration. High correlation coefficients between paired PCAPS indicated that PCAPS have similar responses to water and solute leaching. Several improvements in PCAPS are needed to obtain representative samples under severe flooding conditions. Limited data suggested that ultra-low rate irrigation devices could reduce the water leaching and the potential of pollutant migration to the groundwater because ultra-low rate application devices minimize the soil macropore flow. / Graduation date: 1995
337

Design and feasibility of a permanent system for pesticide application in orchards /

Wilson, Steven M. January 1983 (has links)
Thesis (M.S.)--Ohio State University. / Includes bibliographical references (leaves 63-65). Available online via OhioLINK's ETD Center
338

Gestione BPL e approfondimento dei diversi metodi di studio su comportamento e degradazione di prodotti fitosanitari nel suolo / Management and Deepening of Different Study Methods on Behaviour and Degradation of Pesticides in Soil in Compliance to GLP

MAGISTRATI, PALOMA 09 March 2007 (has links)
La valutazione del comportamento ambientale del metabolita di un pesticida è stato suddiviso in due studi indipendenti ma complementari tra loro utilizzando il metabolita radiomarcato con 14C: 1. Valutazione della degradazione aerobica del 14C-metabolita nel suolo; 2. Valutazione dell'assorbimento e desadsorbimento del 14C-metabolita nel suolo. L'attività di studio delle normative e dei regolamenti concernenti le Buone Pratiche di Laboratorio nell'ambito di studi multisito ed è poi sfociato nella gestione di uno studio di validazione di un metodo di analisi per la determinazione dei residui di glyphosate in frutta ed ortaggi. / The behaviour evaluation of a pesticide metabolite was divided in two different but complementary studies, using the radiolabeled metabolite: 1. evaluation of aerobic degradation of 14C-metabolite in soil; 2. evaluation of sorption of 14C-metabolite in soil. The study of GLP (Good Laboratory Practices) for multisite studies lead to the management of validation study for determination of glyphosate residues in fruits and vegetables.
339

Gene Expression Changes in Prostate Cells upon Exposure to Environmental Anti-androgenic Pesticide Vinclozolin

Prasad, Saurabh 01 October 2012 (has links)
Vinclozolin (VCZ), an antiandrogenic fungicide, is an endocrine disrupting chemical that is known to possess high affinity for the androgen receptor (AR) and modulate expression of critical androgen-dependant genes in the prostate. In this study, viability and expression of AR, NKX3.1 and CYP3A4 genes were measured in androgen-sensitive prostate cells LNCaP after exposure to VCZ and VCZ treated with S9 microsomes in a time and dose dependent manner. NKX3.1 is an androgen regulated gene that plays a vital role in prostate development. CYP3A4 is involved in xenobiotic metabolism. VCZ decreased the viability at high doses after 48 hours which was slightly mitigated by treatment with S9 metabolites. Expression of NKX3.1 and CYP3A4 was upregulated while an initial downregulation of AR was observed. NKX3.1 upregulation corroborates with possibility of antiandrogens to act as androgens in LNCaP. The results illustrate that VCZ can interfere with the expression of critical prostate genes.
340

Development of an enzyme-linked immunosorbent assay to detect antibodies against Bacillus thuringiensis subspecies israelensis in Mallard ducks (Anas platyrhynchos)

Rutherford, Gregory J. 11 February 1992 (has links)
To develop an assay to detect antibodies to Bacillus thuringiensis subsp. israelensis in mallard ducks, a growth curve was first established for the bacterium. The growth curve indicated that the crystal delta endotoxin would be best harvested from the rest of the cell material after 12 hours of growth. The delta endotoxin was solubilized in alkaline conditions followed by treatment with proteases or no treatment. The two differently treated delta endotoxins were purified by column chromatography. Fractions were assayed for duck erythrocyte lysis and cytotoxicity to a mosquito cell line. The proteolyzed sample gave four protein peaks with gel filtration, and the fourth peak containing biological activity was further separated into three protein fractions by anion exchange chromatography; two of the three showed biological activity. These two fractions contained 22 and 23 kD proteins species. The nonproteolyzed sample was separated into two protein fractions by gel filtration; only the first peak contained the biological activity. This fraction was further separated into two fractions by anion exchange chromatography; only the second fraction, containing a 28 kD protein, exhibited the activity. This fraction contained a 28 kD protein. However, the fractions containing 22 or 23 kD proteins originating from the proteolyzed sample showed the highest biological activity. Mallard ducks were repeatedly exposed to an aerosolized commercial preparation of the organism. Sera were collected periodically and tested for the antibody by an enzyme-linked immunosorbent assay (ELISA). Those toxic antigens containing 22 or 23 kD proteins were unsuitable for the assay. The exposed ducks were found to produce antibodies against the first fraction from anion exchange chromatography of the proteolyzed sample. The antibody titres increased as the number of exposures increased. The results suggest that ELISA is applicable for detecting antibodies against B.t.i. in wild ducks using the fraction containing a 50 kD protein. / Graduation date: 1992

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