The Wonderfonteinspruit (WFS) flows through the richest gold mining region in the world and has subsequently been exposed to the related pollution for more than a century. In order to determine the extent of mining related pollution in the WFS, sediment, water, soil, grass and cattle tissue samples were collected, analysed and compared from an experimental group and a control group. This study identified cobalt, nickel, zinc, selenium, cadmium, gold, lead and uranium as elements of interest by comparing sediment samples from the WFS and the Mooi River (MR) (which served as a control or background site). The cobalt concentration was found to be 16.37 times higher, the nickel concentration was 30.4 times higher, the copper concentration was 3.59 times higher, the zinc concentration was 103.49 times higher, the selenium concentration was 7.14 times higher, the cadmium concentration was 17.88 times higher, the gold concentration was 4.78 times higher, the lead concentration was 1.32 times higher and the uranium concentration was 375.78 times higher in the initial comparison with sediments from the MR. These results were all found to be significant. All these elements are by products of non-ferrous mining activities as was described in the literature review. The elevated concentrations of these elements, which were found in the streambed sediment of a site in the Lower-Wonderfonteinspruit, suggest that they could have resulted due to upstream gold mining activities. These gold mining activities were initiated more than a century ago and continue to this day. Analysis of the different particle size fractions (sand, silt and clay fractions) revealed that the highest elemental concentrations were found in the clay sized fractions. The clay sized fraction usually contains secondary soil minerals which have the ability to adsorb dissolved cations onto their surface areas. Further analysis revealed that the sand fraction of the WFS sediment contained a substantial concentration of cobalt, nickel, copper, zinc, lead and uranium which, upon initial inspection could not be explained. X-Ray Diffraction (XRD) analysis revealed that more than 90 % of the WFS sand, silt and clay fractions consisted of quartz, which was much higher than that of the MR. Due to the particle size of quartz, it generally dominates the sand and silt fractions, and finding it at levels above 90 % in the clay sized fraction is thought to be highly irregular. This could be explained by the extraction and processing of gold reefs from the goldfields in the catchment. The gold reefs consisted of quartz veins that were milled to a fine dust and pumped onto slime and sand dumps after the gold was extracted. The most abundant ore minerals found within these dumps were uraninite(UO2), brannerite (UO3Ti2O4), arsenopyrite (FeAsS), cobaltite (CoAsS), galena (PbS), pyrrhotite (FeS), gersdofite (NiAsS) and chromite (FeCr2O4), which contain some of the elements of interest. These dumps are either located in close proximity to the WFS or connected to the WFs via canals or pipelines. Erosion of these dumps would then introduce this finely milled quartz into the stream system. Therefore, the elements found in the sediment of the WFS were not only introduced to the system in the dissolved form, but also in the particulate form. The water samples that were collected from the experimental site (WFS) were found to exceed the cobalt, nickel, copper, zinc, selenium and cadmium concentrations ranges which are normally found in natural waters. In addition to this, the cadmium, lead and nickel concentration in the WFS water samples were found to occasionally exceed the target water quality ranges for livestock water as set by DWAF (1996). Water samples that were collected from the control group were found to exceed only the selenium concentration found in natural water sources as found by Crittenden et al., (2005). Cattle in the experimental group drink directly from the WFS and may stir up the sediment and thereby increasing the elemental concentrations within the water prior to ingestion. The target water quality ranges (TWQR) for livestock watering, as set by DWAF 1996, were exceeded by the average nickel and lead concentrations found in the disturbed WFS water samples. Although the elemental concentrations in the respective water samples were fairly low there was a definite practical significant difference between the WFS water and the MR water samples, as well as the disturbed WFS water and the MR water samples. The WFS water quality seemed to have a very large standard deviation which could serve as an indication that the elemental concentrations are highly variable over time. The elemental concentrations that were found in soil samples from the respective sites were compared to elemental concentrations found in normal agricultural soil as presented by Bergman (1992), which revealed the following results. The cobalt concentrations in the soil samples from the soil along WFS site, soil along MR site and irrigation MR site exceeded the agricultural threshold value. The nickel concentrations in the soil samples from the soil along WFS site, soil along MR site, wetland WFS and irrigation MR site exceeded the agricultural threshold value. The zinc concentrations in the soil samples from the soil along WFS site exceeded the agricultural threshold value. Copper, selenium, cadmium and lead concentrations did not exceed the agricultural threshold values in any of the respective sites. The agricultural threshold value for uranium concentrations was exceeded in the soil samples from the soil along the WFS site and the wetland WFS site. The comparison between the elemental concentrations that were found in the soil samples from the irrigated soil WFS site and the irrigated soil MR site revealed a practically significant difference for the copper, zinc and uranium concentrations. The comparison between the elemental concentrations found in soil samples from the soil along the WFS site and the soil along the MR site revealed a practically significant difference for all elements of interest. The analysis of the elemental concentration in the different particle size fractions of soil samples from all the sites (excluding the irrigated pastures) displayed highest elemental concentrations in the clay sized fraction. The elemental concentrations that were found in this fraction are generally considered to be available for plant uptake, as most of them are usually bound to the surface of secondary soil minerals. The sites with the highest concentration of plant available elements were found to be the soil along WFS site and the wetland WFS site. The elemental concentrations found in the grass samples from the respective sampling sites were compared to elemental concentrations that are normally found in grass pastures (Underwood & Suttle, 2001). The cobalt, nickel, copper and concentrations that were found in the grass samples from most of the sites in both the control and experimental groups were all found to exceed the concentration ranges found in natural pastures. The cadmium and zinc concentrations in the grass samples from the soil along WFS site were found to exceed the respective concentration ranges found in natural pastures. The normal uranium concentration found in irrigated or natural grasses could not be found in an extensive search. Dreesen et al. (1982) reported 0.16 mg/kg uranium in grasses and 1.8 mg/kg uranium in shrubs that grew on soil-covered tailings material. All the sites in the experimental group, including the control WFS site, drastically exceeded these concentrations, which may suggest that the grasses in the experimental sites have been exposed to elevated uranium concentrations. The grass samples with the highest average elemental concentrations were found in the soil along WFS site and irrigated soil WFS site. Lead was to be the only element of interest to have the highest concentration in grass samples from the irrigated soil WFS site. The irrigated soil WFS site portrayed significant transfer factors for nickel, copper, zinc, lead and uranium. This could serve as an indication that the grasses under irrigation in the WFS site absorb and accumulate the highest concentration of elements in respect to the soil concentrations found in the various sites. Therefore, the irrigation from the WFS has a profound effect on the nickel, copper, zinc, lead and uranium concentration in the grass samples under irrigation. The results obtained from the comparative analysis of the elemental concentration in grass samples from the irrigation WFS and irrigation MR sites revealed that all elemental concentrations except for that of zinc had a difference that was practically significant, with the uranium concentration having the largest effect size. The results obtained from the comparative analysis of the elemental concentration in grass samples from the soil along WFS and soil along MR sites revealed that all elemental concentrations had a difference that was practically significant uranium, nickel and zinc concentrations having the largest effect sizes. Considering that a large effect size is achieved at a value equal to or greater than 0.8, the uranium concentration therefore had a massive difference in both comparisons. The results obtained from the comparative analysis of the elemental concentration in grass samples from the wetland WFS and control WFS sites revealed that only the cobalt, nickel and uranium concentrations had differences that were practically significant, with the cobalt concentration having the largest effect size. The results obtained from the comparative analysis of the elemental concentration in the grass samples from the soil along WFS and control WFS sites revealed that all the elemental concentrations except for the lead concentration had a difference that was practically significant. The cobalt, nickel and zinc had the largest effect sizes. The elemental concentrations that were found in cattle liver, kidney and muscle tissue samples from both the experimental and control groups were compared to elemental concentrations normally found in cattle samples as found in Pulse (1994), ATSDR (2004), and ATSDR (2011). This comparison revealed the following results: The nickel, cadmium and lead concentration that were found in the cattle liver, kidney and muscle tissue samples from both the experimental and control groups were found to be within the ranges normally found in cattle. Cobalt concentrations found in the liver and muscle tissue samples of cattle from both the experimental and control groups exceeded the normal ranges, and the cobalt concentrations found in the kidney samples from the experimental group exceeded the normal range. The copper concentration found in the kidney samples from the cattle in the experimental group exceeded that of the normal concentration range. The zinc concentration found in the liver and kidney samples in the cattle from the experimental group, and the kidney samples from the cattle in the control group exceeded the normal range. The selenium concentration found in the liver, kidney and muscle tissue samples in the cattle from the experimental group, and the kidney samples from the cattle in the control group exceeded the normal range. The uranium concentration found in the liver, kidney and muscle tissue samples in the cattle from the experimental group exceeded the normal range. The comparison between cattle tissue samples from the experimental and control group revealed that nickel, zinc, selenium, lead and uranium concentrations all reveal a practically significant difference. Uranium, nickel and lead portrayed the largest differences between the two groups. The uranium concentration in the cattle samples from the experimental group was 126.75 times higher in the liver, 4350 times higher in the kidney, 47.75 times higher in the spleen, 31.6 times higher in the muscle tissue, 60 times higher in the bone and 129 times higher in the hair than that of the cattle samples from the control group. In addition to this, the uranium did not only accumulate in the predicted tissue samples (bone, liver and kidney), but also in the muscle tissue samples. The nickel concentrations in the cattle samples were all found to be higher in the experimental group, with liver 1.4 times higher, kidney 387.5 times higher, spleen 2.1 times higher, muscle tissue 2.8 times higher, bone 167.5 times higher and hair 76.5 times higher than that of the cattle samples from the control group. The lead concentrations found in the cattle samples from the experimental group were found to be 3.8 times higher in the liver, 17.3 times higher in the kidney, 3.3 times higher in the spleen, 3.2 times higher in the muscle tissue, 9 times higher in the bone and 12.2 times higher in the hair than the cattle samples from the control group. Furthermore, the study revealed that the major route of ingestion for all the elements of interest, excluding nickel and cobalt was via the ingestion of grass. The major route for nickel and cobalt ingestion was via soil ingestion. The elemental concentrations from water ingestion were found to be a less significant. It was shown that a predictive cattle consumption model was developed and calibrated from data gathered from a control and experimental group. Animal matter analysed for both groups were related to the cattle age of six years. Although good correlation between observed and simulated values was achieved, the exiting model fit is non-unique. To obtain a more precise model fit a similar dataset is required for both groups, but at a different age. The predictive model also showed that if only grass were to be used as input, there were no significant changes in the correlation between observed and simulated values. This has a huge advantage in terms of costs associated with laboratory analyses as the analysis of grass will be sufficient for using the model. A human health risk assessment was performed based on the results of the cattle consumption model. It was shown that no toxic risk exits for both the control and experimental groups if an intake rate of 0.13 kg of meat per day was assumed. Furthermore, Figure 6-11 clearly indicates that an intake rate of up to 0.38 kg of meat per day also has no toxic risk for both groups, which strongly suggests that there is no risk to the human food chain. The cattle grazing in the WFS appear to be in a good physical condition and according to the farmer; the reproduction rate is at desirable levels. Good farming practices would have also played a significant role to achieve this. / Thesis (MSc (Environmental Sciences))--North-West University, Potchefstroom Campus, 2012.

The Wonderfonteinspruit (WFS) flows through the richest gold mining region in the world and has subsequently been exposed to the related pollution for more than a century. In order to determine the extent of mining related pollution in the WFS, sediment, water, soil, grass and cattle tissue samples were collected, analysed and compared from an experimental group and a control group. This study identified cobalt, nickel, zinc, selenium, cadmium, gold, lead and uranium as elements of interest by comparing sediment samples from the WFS and the Mooi River (MR) (which served as a control or background site). The cobalt concentration was found to be 16.37 times higher, the nickel concentration was 30.4 times higher, the copper concentration was 3.59 times higher, the zinc concentration was 103.49 times higher, the selenium concentration was 7.14 times higher, the cadmium concentration was 17.88 times higher, the gold concentration was 4.78 times higher, the lead concentration was 1.32 times higher and the uranium concentration was 375.78 times higher in the initial comparison with sediments from the MR. These results were all found to be significant. All these elements are by products of non-ferrous mining activities as was described in the literature review. The elevated concentrations of these elements, which were found in the streambed sediment of a site in the Lower-Wonderfonteinspruit, suggest that they could have resulted due to upstream gold mining activities. These gold mining activities were initiated more than a century ago and continue to this day. Analysis of the different particle size fractions (sand, silt and clay fractions) revealed that the highest elemental concentrations were found in the clay sized fractions. The clay sized fraction usually contains secondary soil minerals which have the ability to adsorb dissolved cations onto their surface areas. Further analysis revealed that the sand fraction of the WFS sediment contained a substantial concentration of cobalt, nickel, copper, zinc, lead and uranium which, upon initial inspection could not be explained. X-Ray Diffraction (XRD) analysis revealed that more than 90 % of the WFS sand, silt and clay fractions consisted of quartz, which was much higher than that of the MR. Due to the particle size of quartz, it generally dominates the sand and silt fractions, and finding it at levels above 90 % in the clay sized fraction is thought to be highly irregular. This could be explained by the extraction and processing of gold reefs from the goldfields in the catchment. The gold reefs consisted of quartz veins that were milled to a fine dust and pumped onto slime and sand dumps after the gold was extracted. The most abundant ore minerals found within these dumps were uraninite(UO2), brannerite (UO3Ti2O4), arsenopyrite (FeAsS), cobaltite (CoAsS), galena (PbS), pyrrhotite (FeS), gersdofite (NiAsS) and chromite (FeCr2O4), which contain some of the elements of interest. These dumps are either located in close proximity to the WFS or connected to the WFs via canals or pipelines. Erosion of these dumps would then introduce this finely milled quartz into the stream system. Therefore, the elements found in the sediment of the WFS were not only introduced to the system in the dissolved form, but also in the particulate form. The water samples that were collected from the experimental site (WFS) were found to exceed the cobalt, nickel, copper, zinc, selenium and cadmium concentrations ranges which are normally found in natural waters. In addition to this, the cadmium, lead and nickel concentration in the WFS water samples were found to occasionally exceed the target water quality ranges for livestock water as set by DWAF (1996). Water samples that were collected from the control group were found to exceed only the selenium concentration found in natural water sources as found by Crittenden et al., (2005). Cattle in the experimental group drink directly from the WFS and may stir up the sediment and thereby increasing the elemental concentrations within the water prior to ingestion. The target water quality ranges (TWQR) for livestock watering, as set by DWAF 1996, were exceeded by the average nickel and lead concentrations found in the disturbed WFS water samples. Although the elemental concentrations in the respective water samples were fairly low there was a definite practical significant difference between the WFS water and the MR water samples, as well as the disturbed WFS water and the MR water samples. The WFS water quality seemed to have a very large standard deviation which could serve as an indication that the elemental concentrations are highly variable over time. The elemental concentrations that were found in soil samples from the respective sites were compared to elemental concentrations found in normal agricultural soil as presented by Bergman (1992), which revealed the following results. The cobalt concentrations in the soil samples from the soil along WFS site, soil along MR site and irrigation MR site exceeded the agricultural threshold value. The nickel concentrations in the soil samples from the soil along WFS site, soil along MR site, wetland WFS and irrigation MR site exceeded the agricultural threshold value. The zinc concentrations in the soil samples from the soil along WFS site exceeded the agricultural threshold value. Copper, selenium, cadmium and lead concentrations did not exceed the agricultural threshold values in any of the respective sites. The agricultural threshold value for uranium concentrations was exceeded in the soil samples from the soil along the WFS site and the wetland WFS site. The comparison between the elemental concentrations that were found in the soil samples from the irrigated soil WFS site and the irrigated soil MR site revealed a practically significant difference for the copper, zinc and uranium concentrations. The comparison between the elemental concentrations found in soil samples from the soil along the WFS site and the soil along the MR site revealed a practically significant difference for all elements of interest. The analysis of the elemental concentration in the different particle size fractions of soil samples from all the sites (excluding the irrigated pastures) displayed highest elemental concentrations in the clay sized fraction. The elemental concentrations that were found in this fraction are generally considered to be available for plant uptake, as most of them are usually bound to the surface of secondary soil minerals. The sites with the highest concentration of plant available elements were found to be the soil along WFS site and the wetland WFS site. The elemental concentrations found in the grass samples from the respective sampling sites were compared to elemental concentrations that are normally found in grass pastures (Underwood & Suttle, 2001). The cobalt, nickel, copper and concentrations that were found in the grass samples from most of the sites in both the control and experimental groups were all found to exceed the concentration ranges found in natural pastures. The cadmium and zinc concentrations in the grass samples from the soil along WFS site were found to exceed the respective concentration ranges found in natural pastures. The normal uranium concentration found in irrigated or natural grasses could not be found in an extensive search. Dreesen et al. (1982) reported 0.16 mg/kg uranium in grasses and 1.8 mg/kg uranium in shrubs that grew on soil-covered tailings material. All the sites in the experimental group, including the control WFS site, drastically exceeded these concentrations, which may suggest that the grasses in the experimental sites have been exposed to elevated uranium concentrations. The grass samples with the highest average elemental concentrations were found in the soil along WFS site and irrigated soil WFS site. Lead was to be the only element of interest to have the highest concentration in grass samples from the irrigated soil WFS site. The irrigated soil WFS site portrayed significant transfer factors for nickel, copper, zinc, lead and uranium. This could serve as an indication that the grasses under irrigation in the WFS site absorb and accumulate the highest concentration of elements in respect to the soil concentrations found in the various sites. Therefore, the irrigation from the WFS has a profound effect on the nickel, copper, zinc, lead and uranium concentration in the grass samples under irrigation. The results obtained from the comparative analysis of the elemental concentration in grass samples from the irrigation WFS and irrigation MR sites revealed that all elemental concentrations except for that of zinc had a difference that was practically significant, with the uranium concentration having the largest effect size. The results obtained from the comparative analysis of the elemental concentration in grass samples from the soil along WFS and soil along MR sites revealed that all elemental concentrations had a difference that was practically significant uranium, nickel and zinc concentrations having the largest effect sizes. Considering that a large effect size is achieved at a value equal to or greater than 0.8, the uranium concentration therefore had a massive difference in both comparisons. The results obtained from the comparative analysis of the elemental concentration in grass samples from the wetland WFS and control WFS sites revealed that only the cobalt, nickel and uranium concentrations had differences that were practically significant, with the cobalt concentration having the largest effect size. The results obtained from the comparative analysis of the elemental concentration in the grass samples from the soil along WFS and control WFS sites revealed that all the elemental concentrations except for the lead concentration had a difference that was practically significant. The cobalt, nickel and zinc had the largest effect sizes. The elemental concentrations that were found in cattle liver, kidney and muscle tissue samples from both the experimental and control groups were compared to elemental concentrations normally found in cattle samples as found in Pulse (1994), ATSDR (2004), and ATSDR (2011). This comparison revealed the following results: The nickel, cadmium and lead concentration that were found in the cattle liver, kidney and muscle tissue samples from both the experimental and control groups were found to be within the ranges normally found in cattle. Cobalt concentrations found in the liver and muscle tissue samples of cattle from both the experimental and control groups exceeded the normal ranges, and the cobalt concentrations found in the kidney samples from the experimental group exceeded the normal range. The copper concentration found in the kidney samples from the cattle in the experimental group exceeded that of the normal concentration range. The zinc concentration found in the liver and kidney samples in the cattle from the experimental group, and the kidney samples from the cattle in the control group exceeded the normal range. The selenium concentration found in the liver, kidney and muscle tissue samples in the cattle from the experimental group, and the kidney samples from the cattle in the control group exceeded the normal range. The uranium concentration found in the liver, kidney and muscle tissue samples in the cattle from the experimental group exceeded the normal range. The comparison between cattle tissue samples from the experimental and control group revealed that nickel, zinc, selenium, lead and uranium concentrations all reveal a practically significant difference. Uranium, nickel and lead portrayed the largest differences between the two groups. The uranium concentration in the cattle samples from the experimental group was 126.75 times higher in the liver, 4350 times higher in the kidney, 47.75 times higher in the spleen, 31.6 times higher in the muscle tissue, 60 times higher in the bone and 129 times higher in the hair than that of the cattle samples from the control group. In addition to this, the uranium did not only accumulate in the predicted tissue samples (bone, liver and kidney), but also in the muscle tissue samples. The nickel concentrations in the cattle samples were all found to be higher in the experimental group, with liver 1.4 times higher, kidney 387.5 times higher, spleen 2.1 times higher, muscle tissue 2.8 times higher, bone 167.5 times higher and hair 76.5 times higher than that of the cattle samples from the control group. The lead concentrations found in the cattle samples from the experimental group were found to be 3.8 times higher in the liver, 17.3 times higher in the kidney, 3.3 times higher in the spleen, 3.2 times higher in the muscle tissue, 9 times higher in the bone and 12.2 times higher in the hair than the cattle samples from the control group. Furthermore, the study revealed that the major route of ingestion for all the elements of interest, excluding nickel and cobalt was via the ingestion of grass. The major route for nickel and cobalt ingestion was via soil ingestion. The elemental concentrations from water ingestion were found to be a less significant. It was shown that a predictive cattle consumption model was developed and calibrated from data gathered from a control and experimental group. Animal matter analysed for both groups were related to the cattle age of six years. Although good correlation between observed and simulated values was achieved, the exiting model fit is non-unique. To obtain a more precise model fit a similar dataset is required for both groups, but at a different age. The predictive model also showed that if only grass were to be used as input, there were no significant changes in the correlation between observed and simulated values. This has a huge advantage in terms of costs associated with laboratory analyses as the analysis of grass will be sufficient for using the model. A human health risk assessment was performed based on the results of the cattle consumption model. It was shown that no toxic risk exits for both the control and experimental groups if an intake rate of 0.13 kg of meat per day was assumed. Furthermore, Figure 6-11 clearly indicates that an intake rate of up to 0.38 kg of meat per day also has no toxic risk for both groups, which strongly suggests that there is no risk to the human food chain. The cattle grazing in the WFS appear to be in a good physical condition and according to the farmer; the reproduction rate is at desirable levels. Good farming practices would have also played a significant role to achieve this. / Thesis (MSc (Environmental Sciences))--North-West University, Potchefstroom Campus, 2012.

In freshwater, there is more opportunity for silver (Ag) to interact with organic ligands than in seawater. Triclosan is an antibiotic agent which resembles thyroid hormone T3 and is finding its way into aquatic systems. Preliminary toxicology studies for the frogSCOPE program suggest that triclosan and nanosilver (nanoAg), also used as an antibiotic agent, may be chemically interacting, as they seem to synergistically increase the endocrine-disrupting abilities already observed independently in each chemical. Ag speciation methods can be used to determine if triclosan or thyroid hormone T3 are interacting with Ag ion (Ag+), which gets released over time by nanoAg. To fully utilize Ag speciation methods, however, total Ag in the sample must also be independently analyzed. Here we investigated a new total Ag analysis using cadmium sulfide quantum dots (CdS QDs) as fluorescence probes in solution. This method promises results in a fraction of the time of the established competitive ligand equilibration-solvent extraction (CLE-SE) technique utilizing PDC- and DDC- to bind Ag and bring it out of solution. Following this investigation were a series of experiments using CLE-SE for total Ag and Ag speciation in well water used to house bullfrog tadpoles in frogSCOPE Ag exposure studies. CLE-SE for Ag speciation was also applied to well water samples containing the two levels of nanoAg or Ag+ used in frogSCOPE Ag exposures, and used in ligand competition experiments to examine the potential of triclosan or T3 to act as strong Ag-binding ligands, as compared to glutathione and EDTA, two known Ag-binding ligands. The results of the latter experiments could be used to determine if either of these could be forming complexes with Ag which increase or decrease their delivery to amphibian cells. The fluorometric method using CdS QDs showed no ideal analytical response to nanomolar Ag+, even when commercial QDs were modified and used, so it could not be applied to our samples. Using CLE-SE for total Ag, the well water used as a base for toxicity studies in frogSCOPE contained Ag below the method detection limit of 5 pM. Using the speciation variation of the CLE-SE method, no evidence of naturally-occurring ligands which could produce extractable (hydrophobic) or non-extractable (hydrophilic) Ag complexes was found in this well water. EDTA and glutathione responded as model Ag-binding ligands to form non-extractable hydrophilic Ag complexes in fresh water. T3 behaved like these model ligands, while triclosan enhanced the extractability of Ag in the presence of certain concentrations of the added ligand, DDC-. In another set of experiments, coordination of Ag by triclosan or T3 was not detectable within that analytical window. These results suggest that ionic Ag released over time by nanoAg may be binding T3 and preventing it from reaching its receptor, but confirming the interaction of triclosan and Ag+ will require additional experiments using different analytical windows.

Diabetes mellitus currently affects over 422 million people globally and over 80% of patients with diabetes will develop diabetic retinopathy. Patients with diabetic retinopathy initially develop background retinopathy, which does not cause significant deterioration of visual function; however, background retinopathy may progress and lead to proliferative diabetic retinopathy and diabetic macular oedema, both of which cause severe visual dysfunction if left untreated. Current therapies for diabetic retinopathy include invasive intravitreal injections and laser photocoagulation; however these treatments only attenuate the progression of proliferative diabetic retinopathy and diabetic macular oedema. Aside from prevention by maintaining good blood glucose and blood pressure control, there are currently no treatments to prevent progression to late-stage diabetic retinopathy and new innovations in the field have not significantly progressed. For this reason, we have used untargeted –omics approaches to identify previously unknown pathological pathways in diabetes. In this thesis, I have analysed a range of trace metals in donor retinas and found that total copper was increased in diabetic retinas compared with non-diabetic. This result was replicated in streptozotocin-induced diabetic rat retinas and further evidenced by upregulation of metallothioneins and caeruloplasmin in diabetic rat retinas compared with non-diabetic. Treatment with the copper chelator triethylenetetramine modulated these changes, the downstream effects of which require further study. This is the first description, to our knowledge, of dysregulated copper homeostasis in the diabetic retina. I have also mapped metabolic changes in streptozotocin-induced diabetic rat retinas and found previously undescribed metabolite changes such as diabetes-induced downregulation of scyllo inositol. This coincided with substantial changes to retinal lipids during diabetes and changes to individual lipids were consistent within their respective class. I have also found a pattern whereby regardless of the extent of change to a lipid class in diabetes, lipids containing docosahexaenoic acid (22:6 carbon chain) were consistently downregulated. This is thought to be the first study to describe this range of metabolite changes in the diabetic retina but also the first study to describe this range of metabolite analysis concomitantly within the same tissue sample. The data from this study provides new insights into metallomic and metabolic dysfunction in diabetic retinopathy and shown that these data are reproducible. We suggest that there is plenty of scope for further research to investigate mechanisms behind copper dysregulation, how this affects pathogenesis of diabetic retinopathy along with new insights into dysregulated metabolic pathways.

Submitted by Luciana Sebin (lusebin@ufscar.br) on 2016-10-07T17:54:22Z No. of bitstreams: 1 TeseAFO.pdf: 3549447 bytes, checksum: 4e7cee7e550c3a9888b1a0994be5e4d1 (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2016-10-10T20:05:35Z (GMT) No. of bitstreams: 1 TeseAFO.pdf: 3549447 bytes, checksum: 4e7cee7e550c3a9888b1a0994be5e4d1 (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2016-10-10T20:08:58Z (GMT) No. of bitstreams: 1 TeseAFO.pdf: 3549447 bytes, checksum: 4e7cee7e550c3a9888b1a0994be5e4d1 (MD5) / Made available in DSpace on 2016-10-10T20:31:01Z (GMT). No. of bitstreams: 1 TeseAFO.pdf: 3549447 bytes, checksum: 4e7cee7e550c3a9888b1a0994be5e4d1 (MD5) Previous issue date: 2016-01-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Selenium is essential in animal nutrition; it ensures proper functioning of musculoskeletal, reproductive, and immune system. The intake requirement range for Se is narrow and low levels of Se are required. In order to supply the demand, the animal feed supplementation has grown, considering the knowing of Se deficiency in soils from different countries. This supplementation is made with the use of organoselenium, because of its low toxicity and high bioavailability to the animal. This study targets organoselenium speciation (of Se-methionine and its product of oxidation, Se-O-methionine, and Se-cystine) in animal feed samples and beef using HPLC coupled to ICP-MS/MS. Inorganic species, selenate (Se(VI)) and selenite (Se(IV)), which could be toxic even at low levels, were also determined. The instrumental parameters were optimized and the use of hydrogen as reaction gas to remove the m/z= 80 (Se most abundant isotope) interferences was evaluated, and it demonstrated analytical capacity by using Se standard solutions in presence of interfering elements and CRMs (bovine liver and fish liver) digests indicated a calculated accuracy of 89 and 97 %, respectively. The Se chemical speciation method was applied in samples provided from an experiment with 48 animals (divided into four groups) were fed with Se enriched feed for 82 days. The groups are: (1) cattle feed (control); (2) cattle feed + antioxidants (organoselenium + vitamin E); (3) cattle feed + canola oil and (4) cattle feed + antioxidants (canola oil + organoselenium + vitamin E). A sample preparation method development for complex matrices like animal feed and beef was optimized with an enzyme coquetail. A good separation was obtained and Se species could be easily identified. The method is robust and his been applied for different types of samples with recoveries > 65%. The results infer that a majority of Se in both feed and beef present as Se-methionine. The same method was used to evaluate commercialized feed of swine, poultry and bovine in order to evaluate if the concentrations and species are in agreement with labels. In general the samples attend to legislation according to the evaluated parameters. / O selênio é um elemento essencial na nutrição animal e está associado ao funcionamento saudável dos sistemas músculoesquelético, reprodutivo e imunológico. O valor de ingestão diária recomendado é estreito e baixas concentrações de Se são necessárias. A fim de suprir as necessidades na alimentação animal, a prática de suplementação tem crescido, pois a deficiência de Se em solos de diversos países é comum. Essa suplementação é feita com o emprego de Se orgânico pela sua baixa toxicidade e alta biodisponibilidade para o animal. O presente estudo teve como objetivo a especiação de Se orgânico (como a Se-metionina e seu produto de oxidação, Se-O-metionina, e a Se-cistina) em amostras de ração animal e carne bovina utlizando HPLC acoplado ao ICP-MS/MS. As espécies inorgânicas, selenato (Se(VI)) e selenito (Se(IV)), as quais podem ser tóxicas mesmo em concentrações baixas também foram determinadas no método. A otimização dos parâmetros instrumentais e a avaliação do emprego de hidrogênio como gás de reação com os interferentes para determinação da m/z= 80 para monitoramento do isótopo mais abundante de Se foram realizadas, sendo a capacidade analítica demonstrada com o emprego de soluções padrão de Se na presença de possíveis interferentes e com o emprego de CRMs de fígado bovino e fígado de peixe, e a exatidão calculada foi de 89 e 97 %, respectivamente. A especiação química de Se foi aplicada a amostras provenientes de experimento com 48 animais (divididos em quatro grupos) alimentados com ração enriquecida de Se orgânico durante 82 dias. Os grupos foram: (1) ração animal (controle); (2) ração animal + antioxidantes (Se orgânico + vitamina E); (3) ração animal + óleo de canola e (4) ração animal + antioxidantes (óleo de canola + Se orgânico + vitamina E). O método de preparo de amostra para matrizes complexas, como ração animal e carne bovina foi otimizado com uma mistura de enzimas. Uma boa separação foi obtida e as espécies de Se foram facilmente identificadas. O método foi considerado robusto e tem sido aplicado para diferentes tipos de amostras com recuperações > 65%. Os resultados inferem que Se-metionina é a espécie majoritária nas amostras de rações animal e carne bovina. O método desenvolvido foi aplicado a extratos de ração animal comercializáveis de suínos, aves e bovinos, para verificação da veracidade quanto às espécies sugeridas nos rótulos das embalagens. De forma geral, as amostras atenderam a legislação perante aos quesitos avaliados. / CAPES: 001/2011 / CAPES: 99999.014317/2013-03

The elemental analysis of soil is useful in forensic and environmental sciences. Methods were developed and optimized for two laser-based multi-element analysis techniques: laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and laser-induced breakdown spectroscopy (LIBS). This work represents the first use of a 266 nm laser for forensic soil analysis by LIBS. Sample preparation methods were developed and optimized for a variety of sample types, including pellets for large bulk soil specimens (470 mg) and sediment-laden filters (47 mg), and tape-mounting for small transfer evidence specimens (10 mg). Analytical performance for sediment filter pellets and tape-mounted soils was similar to that achieved with bulk pellets. An inter-laboratory comparison exercise was designed to evaluate the performance of the LA-ICP-MS and LIBS methods, as well as for micro X-ray fluorescence (μXRF), across multiple laboratories. Limits of detection (LODs) were 0.01-23 ppm for LA-ICP-MS, 0.25-574 ppm for LIBS, 16-4400 ppm for µXRF, and well below the levels normally seen in soils. Good intra-laboratory precision (≤ 6 % relative standard deviation (RSD) for LA-ICP-MS; ≤ 8 % for µXRF; ≤ 17 % for LIBS) and inter-laboratory precision (≤ 19 % for LA-ICP-MS; ≤ 25 % for µXRF) were achieved for most elements, which is encouraging for a first inter-laboratory exercise. While LIBS generally has higher LODs and RSDs than LA-ICP-MS, both were capable of generating good quality multi-element data sufficient for discrimination purposes. Multivariate methods using principal components analysis (PCA) and linear discriminant analysis (LDA) were developed for discriminations of soils from different sources. Specimens from different sites that were indistinguishable by color alone were discriminated by elemental analysis. Correct classification rates of 94.5 % or better were achieved in a simulated forensic discrimination of three similar sites for both LIBS and LA-ICP-MS. Results for tape-mounted specimens were nearly identical to those achieved with pellets. Methods were tested on soils from USA, Canada and Tanzania. Within-site heterogeneity was site-specific. Elemental differences were greatest for specimens separated by large distances, even within the same lithology. Elemental profiles can be used to discriminate soils from different locations and narrow down locations even when mineralogy is similar.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Among the several techniques used for provenance studies, the geochronological analysis associated to paleocurrent survey has presented excellent results. Therefore, this study aimed to identifying the sources of the sandstone at the outcrop that gave name to the Penedo Formation, inserted in the Sergipe-Alagoas Basin. This outcrop is located at Penedo’s city, state of Alagoas, northeast of Brazil. The methodology consisted of a continuous bibliographical survey; field work for sample collection and paleocurrent analysis; preparation of samples for concentration of the detrital zircon crystals; chemical-isotopic determination of the crystals with the U-Pb dating, by Laser Ablation Mass Spectrometer (LA-ICP-MS); data processing and the elaboration of this dissertation. The sedimentary record of paleocurrents indicated a contribution coming from north, while the analyzed crystals indicated ages ranging from Mesoarchean (3,098 ± 33 Ma) to Paleozoic (530 ± 12 Ma). This set of ages is related to five groups of sources: Neoproterozoic granites related to the Brasiliano cycle; Mesoproterozoic rocks of the Cabrobró Complex; rocks of the Paleoproterozoic basement coming from the Arapiraca Complex; and finally, rocks of Neo and Mesoarquean ages from rocks of the “Domo Jirau do Ponciano”, south of Alagoas state. Further work with the chemical characterization of zircon crystals of various igneous lithotypes (presented in this dissertation in the form of annex), indicated that these crystals of the Penedo Formation were largely provided from basic igneous or mantle affinity rocks, which ratifies the sources identified here by geocrology and paleocurrent analysis. / Dentre as diversas técnicas empregadas para estudos de proveniência, a análise geocronológica aliada ao levantamento de paleocorrentes tem se destacado com excelentes resultados. Esta pesquisa teve o objetivo de identificar as fontes dos arenitos da seção aflorante que deu nome à Formação Penedo, inserida na Bacia de Sergipe-Alagoas. Este afloramento localiza-se na cidade de Penedo, estado de Alagoas, nordeste do Brasil. A metodologia de trabalho constituiu de levantamento bibliográfico contínuo; missões de campo para coleta de amostra e levantamento de paleocorrentes; preparação das amostras para concentração dos cristais de zircão detríticos; determinação química-isotópica dos cristais com a datação U-Pb, por meio de Espectrometria de Massa por Ablação a Laser (LA-ICP-MS); tratamento de dados e elaboração desta dissertação. O registro sedimentar de paleocorrentes indicaram aporte vindo de norte, enquanto os cristais analisados indicaram idades variando do Mesoarqueano (3.098 ± 33 Ma) ao Paleozóico (530 ± 12 Ma). Este conjunto de idades está relacionado a cinco grupos de fontes: granitos neoproterozóicos relacionados ao ciclo Brasiliano; rochas mesoproterozóicas do Complexo Cabrobró; rochas do embasamento paleoproterozóico provindas do Complexo Arapiraca; e por fim, rochas de idades neo e mesoarqueanas provenientes do Domo Jirau do Ponciano, sul do estado de Alagoas. Trabalho complementar sobre a caracterização química de cristais de zircões de diversos litotipos ígneos (apresentados nesta dissertação na forma de anexo), indicaram que estes cristais da Formação Penedo eram em grande parte oriundos de rochas ígneas básicas ou com afinidade mantélica, ratificando as fontes aqui indentificadas por meio de geocrologia e paleocorrente.

The aim of this diploma thesis is determination of selected metals in unconventional fruit species, specifically in cornelian cherry (Cornus mas), sea buckthorn (Hippophae rhamnoides) and medlar (Mespilus germanica).There is informationabout 16 analysed metals – As, B, Be, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Se, Sn, Pb, V, Zn. There are described analytical techniques for elemental analysis and methods for destruction biological material. Samples for analysis are prepared by using microwave mineralization and ICP-MS for detection. This is described in the experimental part of the diploma thesis. Analysis confirmed that unconventional fruits are rich sources of trace elements.

No description available.

Due to their unique properties, engineered nanomaterials are now widely used in numerous commercial products. Cerium oxide (CeO2) nanoparticles (NPs) are among the most commonly used engineered NPs, with applications in surface coatings, catalysis, the manufacturing of semiconductors, biomedicine and agriculture. With the significant increase in the production and use of CeO2 NPs, concern is increasing over their release into the environment and their subsequent fate and toxicity. In order to evaluate their environmental risk, it is necessary to detect, quantify and characterize the NPs in all environmental compartments. Unfortunately, analyses of NPs in natural systems are challenging due to their small sizes, their low concentrations (∼ ng L-1) and the complexity of environmental matrices, which also contain natural colloids. Single particle inductively coupled plasma mass spectrometry (SP-ICP-MS) is a specific and sensitive technique that enables the detection of very low concentrations (∼ ng L-1) of NPs and it can provide information on their number concentrations, sizes, and size distributions. This technique is often limited by high size detection limits (SDL). However, it is especially important to obtain rigorous size, concentration, and fate data for the smallest NPs, since they are expected to have the greatest environmental risk. To that end, the specific objective of this thesis was to develop an improved method for the detection, quantification, and characterization of CeO2 NPs in complex natural waters using SP-ICP-MS. The project was then divided into several objectives: (1) decrease the SDL for CeO2 NPs; (2) optimize the preparation method for natural water samples; (3) apply the preparation and the analysis methods to detect, quantify, and characterize CeO2 NPs in several natural water samples and commercial products, such as a paint and a stain; (4) identify the origin (natural or engineered) of the detected CeO2 NPs; (5) quantify and characterize the release of CeO2 NPs from paint and stain under natural weathering scenarios; and (6) evaluate the effect of different physicochemical conditions (pH, ionic strength, and NOM) on the fate of CeO2 NPs after their release. A high sensitivity sector field ICP-MS (SF-ICP-MS) with microsecond dwell times (50 μs) was used to lower the SDL of CeO2 NPs to below 4.0 nm. While filtration is often used as a preparation method for SP-ICP-MS, its effect on the concentrations and sizes of NPs is unknown. For this purpose, the interactions between six different membrane filters and CeO2 NPs in aqueous samples were examined. The highest recoveries were observed for polypropylene membranes, where 60 % of the pre-filtration NPs were found in a rainwater and 75% were found in a river water. Recoveries could be increased to over 80% by pre-conditioning the filtration membranes with a multi-element solution. Similar recoveries were obtained when samples were centrifuged at low centrifugal forces (≤1000xg). SF-ICP-MS was then used to detect CeO2 NPs in Montreal rainwater, St. Lawrence River water, a paint, and a stain. A significant decrease in the concentrations of CeO2 NPs, initially contained in paint and stain, was measured over time under different conditions, which was attributed to agglomeration and/or dissolution. Finally, when painted and stained panels were placed outside, the released Ce in the precipitation was mainly in the dissolved form with no significant release of CeO2 NPs. / En raison de leurs propriétés uniques, les nanomatériaux manufacturés sont maintenant largement utilisés dans de nombreux produits commerciaux. Les nanoparticules (NPs) de dioxyde de cérium (CeO2) sont parmi les NPs manufacturées les plus couramment utilisées, avec des applications dans les revêtements de surface, la catalyse, la fabrication de semi-conducteurs, la biomédecine et l’agriculture. Avec l’augmentation significative de la production et l’utilisation des NPs de CeO2, l’inquiétude grandit quant à leur rejet dans l’environnement et à leur devenir et toxicité subséquente. Afin d’évaluer leur risque environnemental, il est nécessaire de détecter, quantifier et caractériser les NPs dans tous les compartiments environnementaux. Malheureusement, les analyses des NPs dans les systèmes naturels sont difficiles en raison de leurs petites tailles, de leurs faibles concentrations (∼ ng L-1) et de la complexité des matrices environnementales, qui contiennent également des colloïdes naturels. La spectrométrie de masse à plasma à couplage inductif en mode particule unique (SP-ICP-MS) est une technique spécifique et sensible qui permet la détection de très faibles concentrations (∼ ng L-1) de NPs en fournissant des informations sur leurs concentrations en nombre, leurs tailles et leurs distributions de taille. Cette technique est souvent limitée par des limites de détection de taille (SDL) élevées. Cependant, il est particulièrement important d’obtenir des données précises sur la taille, la concentration et le devenir des plus petites NPs, qui présentent un plus grand risque environnemental. À cette fin, l’objectif spécifique de cette thèse était de développer une méthode améliorée pour la détection, la quantification et la caractérisation des NPs de CeO2 dans les eaux naturelles complexes à l’aide de SP-ICP-MS. Le projet a ensuite été divisé en plusieurs parties : (1) diminuer la SDL pour les NPs de CeO2; (2) optimiser la méthode de préparation des échantillons d’eau naturelle; (3) appliquer les méthodes de préparation et d’analyse pour détecter, quantifier et caractériser les NPs de CeO2 dans plusieurs échantillons d’eau naturelle et produits commerciaux, telles qu’une peinture et une teinture; (4) identifier l’origine (naturelle ou manufacturée) des NPs de CeO2 détectées; (5) quantifier et caractériser le relargage des NPs de CeO2 de la peinture et de la teinture sous différents scénarios météorologiques; et (6) Évaluer l’effet des différentes conditions physicochimiques (pH, force ionique, et la présence de la matière organique naturelle) sur le devenir des NPs de CeO2 après le relargage. Un ICP-MS à secteur magnétique (SF-ICP-MS) à haute sensibilité avec des temps d’acquisition (i.e. ‘dwell times’) à l’échelle de microsecondes (50 μs) a été utilisé pour diminuer la SDL des NPs de CeO2 à moins de 4.0 nm. Alors que la filtration est souvent utilisée comme méthode de préparation pour le SP-ICP-MS, son effet sur les concentrations et les tailles des NPs est inconnu. Pour cela, les interactions entre six filtres avec des membranes différentes et les NPs de CeO2 dans des échantillons aqueux ont été examinées. Les recouvrements les plus élevés ont été observés pour la membrane de polypropylène, où 60% des NPs de pré-filtration ont été trouvées dans l’eau de pluie et 75% dans les eaux de rivière. Les recouvrements pourraient être augmentés à plus de 80% en préconditionnant les membranes des filtres avec une solution multi-éléments. Des recouvrements similaires ont été obtenus lorsque les échantillons ont été centrifugés à une faible vitesse de rotation (≤1000xg). Le SF-ICP-MS a ensuite été utilisé pour détecter des NPs de CeO2 dans une eau de pluie de Montréal, une eau du fleuve St. Laurent, une peinture et une teinture. En se basant sur le rapport de cérium/lanthane (Ce/La), les NPs de CeO2 détectées dans la pluie sont majoritairement d’origine naturelle alors que celles dans la peinture et la teinture sont manufacturées. Une diminution significative des concentrations des NPs de CeO2, originairement contenues dans la peinture et la teinture, a été mesurée avec le temps, sous l’effet de différentes conditions, ce qui a été attribué à l’agglomération et/ou la dissolution. Finalement, lorsque des panneaux peints et teints ont été placés à l’extérieur, le Ce relargué était principalement sous la forme dissoute, sans relargage significatif des NPs de CeO2.