Provenance determination of rooibos tea using strontium isotope ratio measured by inductively coupled plasma mass spectrometry
- Authors: Fouda Mbanga, Bienvenu Gael
- Date: 2016
- Subjects: Strontium compounds - Analysis , Strontium - Isotopes , Provenance trials , Inductively coupled plasma mass spectrometry , Rooibos tea
- Language: English
- Type: Masters (Thesis)
- Identifier: http://ujcontent.uj.ac.za8080/10210/367403 , http://hdl.handle.net/10210/251099 , uj:26177
- Description: M.Sc. (Chemistry) , Abstract: Rooibos tea is gaining importance as an herbal drink and product enhancer in the beverage, food, nutraceutical and cosmetic markets. Popular food products such as rooibos tea can be a target of fraudulent scheme, which consists of deliberate misrepresentation with the aim to mislead buyers with regard to the true product or any of its ingredients. Determination of the provenance of rooibos tea (fingerprinting) may play a key role in ensuring consumer safety, decreasing damage to producers and in creating awareness about potential use of such tool as deterrent to misleading traders. Among the fingerprinting techniques, inorganic mass spectrometry based on stable isotope ratios such as 87Sr/86Sr is used for determining the origin of various agricultural products. The purpose of this work was to evaluate the potential use of 87Sr/86Sr isotope ratio as a tool for determining the origin of the South African Rooibois tea. The ratio was determined by single quadrupole inductively coupled plasma mass spectrometry. Rooibos tea leaves and soil samples collected from seven tea growing farms in Clanwilliam district and the neighboring Northern Cape region were mineralized and total concentrations of the isotopes determined using internal standardization and external calibration. It was found that scandium (Sc) cannot be used as internal standard since it is present in tea leaves. Hence, throughout this work 69Ga, 115In, and 175Lu were used for instrument drift correction. The evaluation of 87Sr/86Sr ratio was difficult due to isobaric interference of 87Rb on 87Sr. To overcome this challenge, the two isotopes were separated successfully on Dowex 50W-X8 resin by metal-EDTA and metal-DCTA complex elution prior to isotopes ratio determination. Accuracy of the method was checked using tea leaves and sandy soil certified reference materials INCT-TL-1 and CRM-SA-C, respectively. The limits of detection (LOD) and of quantification (LOQ) were between 0.13-0.82 μg L-1 and 0.44-2.75 μg L-1, respectively. The lowness of the LOD and LOQ showed that analysis could be repeated. It was found that DCTA elution method was more efficient than the EDTA one because it complexes metal ions more strongly. The results obtained for 87Sr/86Sr isotope ratio in all the seven farms showed lack of a good correlation between the soil and the tea leaf samples.
- Full Text:
- Authors: Fouda Mbanga, Bienvenu Gael
- Date: 2016
- Subjects: Strontium compounds - Analysis , Strontium - Isotopes , Provenance trials , Inductively coupled plasma mass spectrometry , Rooibos tea
- Language: English
- Type: Masters (Thesis)
- Identifier: http://ujcontent.uj.ac.za8080/10210/367403 , http://hdl.handle.net/10210/251099 , uj:26177
- Description: M.Sc. (Chemistry) , Abstract: Rooibos tea is gaining importance as an herbal drink and product enhancer in the beverage, food, nutraceutical and cosmetic markets. Popular food products such as rooibos tea can be a target of fraudulent scheme, which consists of deliberate misrepresentation with the aim to mislead buyers with regard to the true product or any of its ingredients. Determination of the provenance of rooibos tea (fingerprinting) may play a key role in ensuring consumer safety, decreasing damage to producers and in creating awareness about potential use of such tool as deterrent to misleading traders. Among the fingerprinting techniques, inorganic mass spectrometry based on stable isotope ratios such as 87Sr/86Sr is used for determining the origin of various agricultural products. The purpose of this work was to evaluate the potential use of 87Sr/86Sr isotope ratio as a tool for determining the origin of the South African Rooibois tea. The ratio was determined by single quadrupole inductively coupled plasma mass spectrometry. Rooibos tea leaves and soil samples collected from seven tea growing farms in Clanwilliam district and the neighboring Northern Cape region were mineralized and total concentrations of the isotopes determined using internal standardization and external calibration. It was found that scandium (Sc) cannot be used as internal standard since it is present in tea leaves. Hence, throughout this work 69Ga, 115In, and 175Lu were used for instrument drift correction. The evaluation of 87Sr/86Sr ratio was difficult due to isobaric interference of 87Rb on 87Sr. To overcome this challenge, the two isotopes were separated successfully on Dowex 50W-X8 resin by metal-EDTA and metal-DCTA complex elution prior to isotopes ratio determination. Accuracy of the method was checked using tea leaves and sandy soil certified reference materials INCT-TL-1 and CRM-SA-C, respectively. The limits of detection (LOD) and of quantification (LOQ) were between 0.13-0.82 μg L-1 and 0.44-2.75 μg L-1, respectively. The lowness of the LOD and LOQ showed that analysis could be repeated. It was found that DCTA elution method was more efficient than the EDTA one because it complexes metal ions more strongly. The results obtained for 87Sr/86Sr isotope ratio in all the seven farms showed lack of a good correlation between the soil and the tea leaf samples.
- Full Text:
Method development for the digestion and analysis of four common sedimentary lithologies using ICP-OES and ICP-MS
- Authors: Downer, Nicholas Ramsey
- Date: 2010-03-25T06:44:39Z
- Subjects: Sedimentology , Inductively coupled plasma spectrometry , Inductively coupled plasma mass spectrometry
- Type: Thesis
- Identifier: uj:6701 , http://hdl.handle.net/10210/3103
- Description: M.Sc. , The understanding of the classification and origin of geological systems is facilitated by the acquisition of accurate and precise analytical data. New instrumentation is rapidly developed for the preparation and quantitative analysis of geological materials using smaller amounts of sample, with lower limits of detection and faster analysis times. The development of new methodologies is crucial for the effective utilisation of new instrumentation. This study was conceptualised because of the relationship between the Department of Geology and the Central Analytical Facility of the Faculty of Science, University of Johannesburg. There is a high demand for accurate and precise chemical data for various lithologies and the availability of high-end analytical equipment, but little practical expertise to utilise this equipment to its full potential. The study is centred round the analysis of four common sedimentary lithological groups that are routinely studied by the Department of Geology namely carbonate rocks, shales, iron ore and manganese ore. A large literature base exists for the decomposition and analysis of geological materials. The bulk of this literature is centred round more established and conventional methods of sample preparation and analysis. The use of microwave digestion instrumentation and methodologies in recent times has revolutionised sample decomposition with shorter decomposition times, smaller sample masses required for decomposition, lower loss of analytes to volatilisation and creating a safer laboratory environment for analysts to work in. Inductively coupled plasma optical emission spectroscopy (ICP-OES) is a more mature method of sample analysis, being commercialised in the mid 1970’s, while inductively coupled plasma mass spectroscopy (ICP-MS) is a newer technique, v being commercialised as of the mid 1980’s. These two techniques are multi-element techniques, with low limits of detection and fast analysis times for a plethora of analytes, over seventy elements for ICP-OES and over eighty elements for ICP-MS. Samples from all four lithological groups were successfully digested in a microwave digestion unit with varying combinations of nitric acid (HNO3), hydrochloric acid (HCl), perchloric acid (HClO4) and hydrofluoric acid (HF) and various digestion programs. Accurate and repeatable methods of analysis were developed for iron, manganese, calcium and potassium for all four lithologies with ICP-OES; aluminium was successfully determined for shale, iron and manganese ore with ICP-OES. Titanium, sodium, arsenic, barium, bismuth, chromium, copper, molybdenum, scandium, strontium and vanadium were determined for all four lithotypes with acceptable accuracy and repeatability using ICP-MS.
- Full Text:
- Authors: Downer, Nicholas Ramsey
- Date: 2010-03-25T06:44:39Z
- Subjects: Sedimentology , Inductively coupled plasma spectrometry , Inductively coupled plasma mass spectrometry
- Type: Thesis
- Identifier: uj:6701 , http://hdl.handle.net/10210/3103
- Description: M.Sc. , The understanding of the classification and origin of geological systems is facilitated by the acquisition of accurate and precise analytical data. New instrumentation is rapidly developed for the preparation and quantitative analysis of geological materials using smaller amounts of sample, with lower limits of detection and faster analysis times. The development of new methodologies is crucial for the effective utilisation of new instrumentation. This study was conceptualised because of the relationship between the Department of Geology and the Central Analytical Facility of the Faculty of Science, University of Johannesburg. There is a high demand for accurate and precise chemical data for various lithologies and the availability of high-end analytical equipment, but little practical expertise to utilise this equipment to its full potential. The study is centred round the analysis of four common sedimentary lithological groups that are routinely studied by the Department of Geology namely carbonate rocks, shales, iron ore and manganese ore. A large literature base exists for the decomposition and analysis of geological materials. The bulk of this literature is centred round more established and conventional methods of sample preparation and analysis. The use of microwave digestion instrumentation and methodologies in recent times has revolutionised sample decomposition with shorter decomposition times, smaller sample masses required for decomposition, lower loss of analytes to volatilisation and creating a safer laboratory environment for analysts to work in. Inductively coupled plasma optical emission spectroscopy (ICP-OES) is a more mature method of sample analysis, being commercialised in the mid 1970’s, while inductively coupled plasma mass spectroscopy (ICP-MS) is a newer technique, v being commercialised as of the mid 1980’s. These two techniques are multi-element techniques, with low limits of detection and fast analysis times for a plethora of analytes, over seventy elements for ICP-OES and over eighty elements for ICP-MS. Samples from all four lithological groups were successfully digested in a microwave digestion unit with varying combinations of nitric acid (HNO3), hydrochloric acid (HCl), perchloric acid (HClO4) and hydrofluoric acid (HF) and various digestion programs. Accurate and repeatable methods of analysis were developed for iron, manganese, calcium and potassium for all four lithologies with ICP-OES; aluminium was successfully determined for shale, iron and manganese ore with ICP-OES. Titanium, sodium, arsenic, barium, bismuth, chromium, copper, molybdenum, scandium, strontium and vanadium were determined for all four lithotypes with acceptable accuracy and repeatability using ICP-MS.
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The classification of agricultural products according to geographical origin by means of quadrupole-based ICP-mass spectrometry for the determination of ¹¹B/¹°B isotope ratios, and the study of boron isotope fractionation
- Authors: Greeff, Liezl
- Date: 2010-04-01T05:32:05Z
- Subjects: Wine and wine making , Boron isotopes , Inductively coupled plasma mass spectrometry , Provenance trials
- Type: Thesis
- Identifier: uj:6740 , http://hdl.handle.net/10210/3148
- Description: M.Sc. , The 11B/10B stable isotope ratio in wine- and provenance soil samples of four South African wine regions was determined by means of quadrupole inductively coupled plasma mass spectrometry (ICP-MS). The data obtained was combined with multi-element results for the same samples. Discriminant analysis and ANOVA statistics were utilized to create a footprint of wines compared to their provenance soil. The results showed that the stable boron isotope ratio was a distinguishable characteristic in wine and soil samples for the Stellenbosch, Robertson, Swartland, and Walker Bay wine regions. The potential improvement of precision and accuracy was investigated specifically for ICP-QMS (quadrupole mass spectrometry) analysis of boron isotope ratios. Sample preparation methods for the matrices used in this work were developed and applied. The influence of the matrix components was investigated. Ion exchange separation procedures were developed for the separation of total B from the wine and soil matrices. Results were treated mathematically to minimize mass bias effects. It was found that combined matrix effects and TDS (total dissolved solids) deposition did have a pronounced effect on the 11B/10B isotope ratios of the samples. The possibility of boron isotope fractionation was investigated in vine plants. Hydroponic experiments were set up with test plants of two cultivars. A 10B enriched nutrient solution or growth solution with natural 11B/10B ratio was supplied to the plants during alternating periods of 5 weeks each. New growth leaves were harvested once every week during each of these time periods. All samples were carefully prepared and analyzed to determine the relationship of the 11B/10B ratio in the leaves compared to that of the supplied nutrient solution. It was observed that the 11B/10B isotope ratio of the growth solution had an influence on the 11B/10B stable isotope ratio in new growth leaves of vine plants.
- Full Text:
- Authors: Greeff, Liezl
- Date: 2010-04-01T05:32:05Z
- Subjects: Wine and wine making , Boron isotopes , Inductively coupled plasma mass spectrometry , Provenance trials
- Type: Thesis
- Identifier: uj:6740 , http://hdl.handle.net/10210/3148
- Description: M.Sc. , The 11B/10B stable isotope ratio in wine- and provenance soil samples of four South African wine regions was determined by means of quadrupole inductively coupled plasma mass spectrometry (ICP-MS). The data obtained was combined with multi-element results for the same samples. Discriminant analysis and ANOVA statistics were utilized to create a footprint of wines compared to their provenance soil. The results showed that the stable boron isotope ratio was a distinguishable characteristic in wine and soil samples for the Stellenbosch, Robertson, Swartland, and Walker Bay wine regions. The potential improvement of precision and accuracy was investigated specifically for ICP-QMS (quadrupole mass spectrometry) analysis of boron isotope ratios. Sample preparation methods for the matrices used in this work were developed and applied. The influence of the matrix components was investigated. Ion exchange separation procedures were developed for the separation of total B from the wine and soil matrices. Results were treated mathematically to minimize mass bias effects. It was found that combined matrix effects and TDS (total dissolved solids) deposition did have a pronounced effect on the 11B/10B isotope ratios of the samples. The possibility of boron isotope fractionation was investigated in vine plants. Hydroponic experiments were set up with test plants of two cultivars. A 10B enriched nutrient solution or growth solution with natural 11B/10B ratio was supplied to the plants during alternating periods of 5 weeks each. New growth leaves were harvested once every week during each of these time periods. All samples were carefully prepared and analyzed to determine the relationship of the 11B/10B ratio in the leaves compared to that of the supplied nutrient solution. It was observed that the 11B/10B isotope ratio of the growth solution had an influence on the 11B/10B stable isotope ratio in new growth leaves of vine plants.
- Full Text:
Provenance determination of South African wines with quadrupole-based ICP-MS measurements of ¹¹B/¹°B isotope ratios
- Authors: De Bruyn, Riette
- Date: 2009-11-16T06:21:56Z
- Subjects: Wine and wine making - South Africa , Inductively coupled plasma mass spectrometry , Boron isotopes
- Type: Thesis
- Identifier: uj:8639 , http://hdl.handle.net/10210/2997
- Description: M.Sc. , The origin of a wine plays a key role in establishing the quality and the price the consumer is prepared to pay. Fingerprinting techniques based on multi-element data combined with multivariate statistical analysis as well as isotope ratio data for certain elements such as boron (11B/10B) and strontium (87Sr/86Sr) are being developed and have been used for provenance determination of wine with varying degrees of success. The aim of this study was to develop a method to determine boron isotope ratios (11B/10B) with the required precision using ICP-MS (inductively coupled plasma mass spectrometry) in soil and wine samples and applying this method to establish the origin of South African wines. Analytical difficulties such as the boron memory effect, dead time, mass bias drift and matrix effects were investigated. Although the memory effect, dead time and mass bias drift were satisfactorily resolved, it was not possible to determine what the cause of all the observed matrix effects was during this study. The method was used to categorise wines from the Robertson, Swartland and Stellenbosch regions and an attempt was made to link the measured boron isotope ratios with that obtained from the corresponding provenance soils. The 11B/10B isotope ratios for the wine samples (Robertson: 4.202 ± 0.014, Swartland: 4.173 ± 0.013 and Stellenbosch: 4.174 ± 0.028) were, however, higher than the ratios obtained for the soil samples (Robertson: 4.108 ± 0.020, Swartland: 4.070 ± 0.023 and Stellenbosch: 4.124 ± 0.039). It was possible to distinguish, using the boron isotope ratios (wine and soil samples), between the Robertson area (Breede River region) and the Swartland area (Coastal region). The wine and soil 11B/10B isotope ratios obtained for the Stellenbosch area (Coastal region) overlapped with the 11B/10B isotope ratios of the Robertson and Swartland regions making it impossible to differentiate it from these two regions.
- Full Text:
- Authors: De Bruyn, Riette
- Date: 2009-11-16T06:21:56Z
- Subjects: Wine and wine making - South Africa , Inductively coupled plasma mass spectrometry , Boron isotopes
- Type: Thesis
- Identifier: uj:8639 , http://hdl.handle.net/10210/2997
- Description: M.Sc. , The origin of a wine plays a key role in establishing the quality and the price the consumer is prepared to pay. Fingerprinting techniques based on multi-element data combined with multivariate statistical analysis as well as isotope ratio data for certain elements such as boron (11B/10B) and strontium (87Sr/86Sr) are being developed and have been used for provenance determination of wine with varying degrees of success. The aim of this study was to develop a method to determine boron isotope ratios (11B/10B) with the required precision using ICP-MS (inductively coupled plasma mass spectrometry) in soil and wine samples and applying this method to establish the origin of South African wines. Analytical difficulties such as the boron memory effect, dead time, mass bias drift and matrix effects were investigated. Although the memory effect, dead time and mass bias drift were satisfactorily resolved, it was not possible to determine what the cause of all the observed matrix effects was during this study. The method was used to categorise wines from the Robertson, Swartland and Stellenbosch regions and an attempt was made to link the measured boron isotope ratios with that obtained from the corresponding provenance soils. The 11B/10B isotope ratios for the wine samples (Robertson: 4.202 ± 0.014, Swartland: 4.173 ± 0.013 and Stellenbosch: 4.174 ± 0.028) were, however, higher than the ratios obtained for the soil samples (Robertson: 4.108 ± 0.020, Swartland: 4.070 ± 0.023 and Stellenbosch: 4.124 ± 0.039). It was possible to distinguish, using the boron isotope ratios (wine and soil samples), between the Robertson area (Breede River region) and the Swartland area (Coastal region). The wine and soil 11B/10B isotope ratios obtained for the Stellenbosch area (Coastal region) overlapped with the 11B/10B isotope ratios of the Robertson and Swartland regions making it impossible to differentiate it from these two regions.
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Laser ablation ICP-MS age determination of detrital zircon populations in the Phanerozoic Cape and Lower Karoo Supergroups (South Africa) and correlatives in Argentina.
- Authors: Vorster, Clarisa
- Date: 2014-01-14
- Subjects: Karoo Supergroup , Cape Supergroup , Zircon - South Africa , Zircon - Argentinia , Inductively coupled plasma mass spectrometry , Geochronometry
- Type: Thesis
- Identifier: uj:7897 , http://hdl.handle.net/10210/8789
- Description: Ph.D. (Geology) , The successions of the Cape- and Karoo Supergroups preserve an integrated history of sedimentation along the paleo-Pacific margin of Gondwana from the Paleozoic to the Early Mesozoic. The Cape- and Karoo Supergroups have been well studied with regard to stratigraphy, sedimentary facies and depositional environment. However, the nature and location of their source regions, especially for the changeover from deposition within an Atlantic-type continental margin basin for the successions of the Cape Supergroup to an Andean-type continental foreland basin for some of the units of the Karoo Supergroup, remains poorly understood. In order to shed light on the nature of these source regions, a comprehensive U-Pb detrital zircon study of the successions of the Cape- and lower Karoo Supergroups was launched. A representative number of samples from the upper and lower successions of the Table Mountain- Bokkeveld- and Witteberg Groups of the Cape Supergroup as well as the Dwyka and Ecca Groups of the Karoo Supergroup were collected throughout the western, southwestern and southern Cape region. A few samples of the Dwyka Group were also collected within the more eastern outcrop regions of the succession located in Kwazulu-Natal. The sedimentary rocks of the Natal Group and Msikaba Formation have long been regarded as coeval with the Cape Supergroup. Similar to the successions of the Cape- and Karoo Supergroups, very little is known about their sedimentary source regions. Also, their relative age of sedimentation remains poorly constrained. The U-Pb detrital zircon study of the successions of the Cape- and lower Karoo Supergroups was thus extended so as to include the successions of the Natal Group and Msikaba Formation. The detrital zircon age populations of the successions of the Natal Group and Msikaba Formation would not only improve the present understanding with regards to the sedimentary source regions to these units but would also facilitate the evaluation of possible correlations between these units and the stratigraphic units of the Cape Supergroup. Samples of both the lower Durban Formation and the upper Mariannhill Formation of the Natal Group and the Msikaba Formation (which is presently regarded as being part of the Cape Supergroup) were therefore collected within their respective outcrop regions in the Kwazulu-Natal area. The similarities in litho- and bio-stratigraphy between the successions of the Cape- and Karoo Supergroups and those of the Ordovician to Early Permian successions of the Ventania System and the Ordovician to Silurian successions of the Tandilia System in Argentina have long been recognized. Although the detrital zircon populations of some of the formations within these Systems have been evaluated in the past, it is yet to be determined whether these successions and those of the Cape- and lower Karoo Supergroups have certain source regions in common. In order to facilitate such a comparison, samples of selected units of the Ventania System were therefore collected near Sierra de la Ventania, while a sample of the Balcarce Formation of the Tandilia System was obtained near Mar del Plata. The detrital zircon age populations of the successions of the Ventania and Tandilia Systems were also further evaluated in the light of establishing or confirming a time-correlation between these formations and those of the Cape- and lower Karoo Supergroups. U-Pb age determination of the detrital zircons population of the samples was conducted by means of Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS). Although LA-ICP-MS is a routine, well-established technique where the U-Pb age determination of detrital zircons is concerned, it was yet to be established at the centralized analytical facility of the University of Johannesburg, SPECTRUM, using the instrumentation currently available (i.e. 213nm Nd:YAG laser coupled to Quadrupole-based ICP-MS). The U-Pb age determination of detrital zircons was therefore preceded by a fair amount of instrument optimization and method development. Well studied shortcomings of U-Pb detrital zircon dating by LA-ICP-MS such as laser induced elemental fractionation, mass discrimination effects and as well as the possible occurrence of minor common-Pb needs were addressed and corrected for. The detrital zircon populations of successions in the Cape Supergroup have a distinct major Neoproterozoic to Early Cambrian age component, which can be attributed to an input of detritus from successions related to the Pan-African Orogeny in South Africa, such as the Gariep- and Saldania Belts located towards the north of the Cape Basin. A substantial amount of Mesoproterozoic detrital zircon grains is also present in all the samples from the successions of the Cape Supergroup. These grains of Mesoproterozoic age were probably derived from the Namaqua-Natal Metamorphic Province, which is also regarded as the source of some minor amounts of Paleoproterozoic detrital zircon grains. The near absence of Archean grains from the detrital zircon populations of the successions of the Cape Supergroup is notable, and is thought to be due to the Namaqua-Natal Metamorphic Province acting as a geomorphological barrier at the time of their deposition. The minor Paleozoic (Ordovician to Carboniferous) detrital zircon populations in the samples from the formations of the Cape Supergroup increase progressively upwards through the succession. ....
- Full Text:
- Authors: Vorster, Clarisa
- Date: 2014-01-14
- Subjects: Karoo Supergroup , Cape Supergroup , Zircon - South Africa , Zircon - Argentinia , Inductively coupled plasma mass spectrometry , Geochronometry
- Type: Thesis
- Identifier: uj:7897 , http://hdl.handle.net/10210/8789
- Description: Ph.D. (Geology) , The successions of the Cape- and Karoo Supergroups preserve an integrated history of sedimentation along the paleo-Pacific margin of Gondwana from the Paleozoic to the Early Mesozoic. The Cape- and Karoo Supergroups have been well studied with regard to stratigraphy, sedimentary facies and depositional environment. However, the nature and location of their source regions, especially for the changeover from deposition within an Atlantic-type continental margin basin for the successions of the Cape Supergroup to an Andean-type continental foreland basin for some of the units of the Karoo Supergroup, remains poorly understood. In order to shed light on the nature of these source regions, a comprehensive U-Pb detrital zircon study of the successions of the Cape- and lower Karoo Supergroups was launched. A representative number of samples from the upper and lower successions of the Table Mountain- Bokkeveld- and Witteberg Groups of the Cape Supergroup as well as the Dwyka and Ecca Groups of the Karoo Supergroup were collected throughout the western, southwestern and southern Cape region. A few samples of the Dwyka Group were also collected within the more eastern outcrop regions of the succession located in Kwazulu-Natal. The sedimentary rocks of the Natal Group and Msikaba Formation have long been regarded as coeval with the Cape Supergroup. Similar to the successions of the Cape- and Karoo Supergroups, very little is known about their sedimentary source regions. Also, their relative age of sedimentation remains poorly constrained. The U-Pb detrital zircon study of the successions of the Cape- and lower Karoo Supergroups was thus extended so as to include the successions of the Natal Group and Msikaba Formation. The detrital zircon age populations of the successions of the Natal Group and Msikaba Formation would not only improve the present understanding with regards to the sedimentary source regions to these units but would also facilitate the evaluation of possible correlations between these units and the stratigraphic units of the Cape Supergroup. Samples of both the lower Durban Formation and the upper Mariannhill Formation of the Natal Group and the Msikaba Formation (which is presently regarded as being part of the Cape Supergroup) were therefore collected within their respective outcrop regions in the Kwazulu-Natal area. The similarities in litho- and bio-stratigraphy between the successions of the Cape- and Karoo Supergroups and those of the Ordovician to Early Permian successions of the Ventania System and the Ordovician to Silurian successions of the Tandilia System in Argentina have long been recognized. Although the detrital zircon populations of some of the formations within these Systems have been evaluated in the past, it is yet to be determined whether these successions and those of the Cape- and lower Karoo Supergroups have certain source regions in common. In order to facilitate such a comparison, samples of selected units of the Ventania System were therefore collected near Sierra de la Ventania, while a sample of the Balcarce Formation of the Tandilia System was obtained near Mar del Plata. The detrital zircon age populations of the successions of the Ventania and Tandilia Systems were also further evaluated in the light of establishing or confirming a time-correlation between these formations and those of the Cape- and lower Karoo Supergroups. U-Pb age determination of the detrital zircons population of the samples was conducted by means of Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS). Although LA-ICP-MS is a routine, well-established technique where the U-Pb age determination of detrital zircons is concerned, it was yet to be established at the centralized analytical facility of the University of Johannesburg, SPECTRUM, using the instrumentation currently available (i.e. 213nm Nd:YAG laser coupled to Quadrupole-based ICP-MS). The U-Pb age determination of detrital zircons was therefore preceded by a fair amount of instrument optimization and method development. Well studied shortcomings of U-Pb detrital zircon dating by LA-ICP-MS such as laser induced elemental fractionation, mass discrimination effects and as well as the possible occurrence of minor common-Pb needs were addressed and corrected for. The detrital zircon populations of successions in the Cape Supergroup have a distinct major Neoproterozoic to Early Cambrian age component, which can be attributed to an input of detritus from successions related to the Pan-African Orogeny in South Africa, such as the Gariep- and Saldania Belts located towards the north of the Cape Basin. A substantial amount of Mesoproterozoic detrital zircon grains is also present in all the samples from the successions of the Cape Supergroup. These grains of Mesoproterozoic age were probably derived from the Namaqua-Natal Metamorphic Province, which is also regarded as the source of some minor amounts of Paleoproterozoic detrital zircon grains. The near absence of Archean grains from the detrital zircon populations of the successions of the Cape Supergroup is notable, and is thought to be due to the Namaqua-Natal Metamorphic Province acting as a geomorphological barrier at the time of their deposition. The minor Paleozoic (Ordovician to Carboniferous) detrital zircon populations in the samples from the formations of the Cape Supergroup increase progressively upwards through the succession. ....
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Qualitative structure-activity relationship (QSAR) studies of 3,5-dicaffeoylquinic acid geometrical isomers with the aid of density functional theory (DFT), liquid chromatography mass spectrometry (LC-MS) and HIV-1 integrase docking studies
- Authors: Makola, Mpho Mankone
- Date: 2016
- Subjects: Plant metabolites , Phytochemicals , Plant extracts - Therapeutic use , Alkali metals , Inductively coupled plasma mass spectrometry
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/124743 , uj:20954
- Description: Abstract: Please refer to full text to view abstract , M.Sc. (Biochemistry)
- Full Text:
- Authors: Makola, Mpho Mankone
- Date: 2016
- Subjects: Plant metabolites , Phytochemicals , Plant extracts - Therapeutic use , Alkali metals , Inductively coupled plasma mass spectrometry
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/124743 , uj:20954
- Description: Abstract: Please refer to full text to view abstract , M.Sc. (Biochemistry)
- Full Text:
Metal accumulation in Labeo capensis Smith, 1841 and the potential use of Argulus japonicas Thiele, 1900 as a sentinel for metal accumulation from the Vaal Dam, South Africa
- Authors: Lynch, Lloyd Patrick
- Date: 2015-06-30
- Subjects: Labeo capensis - Histology , Histochemistry , Fishes - Ecology - South Africa - Vaal Dam , Freshwater fishes - South Africa - Vaal Dam - UJ Island , Metal catalysis , Inductively coupled plasma mass spectrometry
- Type: Thesis
- Identifier: uj:13656 , http://hdl.handle.net/10210/13840
- Description: MSc. (Zoology) , The use of parasites in aquatic monitoring studies has increased over the last two decades, due to the remarkable ability to accumulate metals to higher concentrations than their hosts. Studies utilizing parasitic organisms have primarily focused on the use of endoparasites, resulting in limited knowledge on the potential of ectoparasitic organisms. The present study was undertaken in April 2013 at UJ Island (26°52.249‟S; 20°10.249‟E) in the Vaal Dam where 22 Labeo capensis Smith, 1841 were collected with the aid of gill nets. All Argulus japonicus Thiele, 1900 specimens were collected off of each host upon host collection, and kept alive for 24 hours prior to being frozen, to allow for digestion of intestinum content. Water and sediment samples were collected on site, and water quality data was received from Rand Water Analytical Facility in Vereeniging for the sampling period, as this organisation routinely monitors the physico-chemical parameters and metal concentrations of the Vaal Dam. The fish were sacrificed by severing the spinal cord, and blood, gill arch, gill filament, kidney, liver, muscle and skin tissues were collected from each fish for metal analysis. All samples were frozen and transported to the University of Johannesburg for analysis. Water, fish tissue, parasite and sediment samples underwent acid digestion utilizing closed vessel microwave digestion techniques, and analysis was performed utilizing both Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) and Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES). Fish muscle tissue underwent further Cold Vapour Atomic Absorption Spectrometry (CVAAS) analysis. Selected A. japonicus specimens were prepared for fluorescence microscopy. These specimens underwent photo irradiation and were treated with Phen Green FL cell permeate diacetate stain to visually locate regions where the metals were being accumulated. The results from the metal analysis indicated that metals present within the Vaal Dam water are all at trace levels. The comparison of metal concentrations between the water, sediment and fish tissues revealed that sediment contains the highest concentrations for metals, followed by fish tissues and water at the lowest concentrations. This trend exists as a result of the underlying geological morphology of the Vaal Dam, the physiological and biological characteristics of L. capensis, and the physico-chemical variables of the water. The risk assessment performed on the muscle tissue revealed that the levels of arsenic, cadmium and selenium were above the safety threshold values for human consumption. The analysis of the A. japonicus specimens revealed that the selected techniques were not adequate for the analysis of individual specimens, as specimens were too small...
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- Authors: Lynch, Lloyd Patrick
- Date: 2015-06-30
- Subjects: Labeo capensis - Histology , Histochemistry , Fishes - Ecology - South Africa - Vaal Dam , Freshwater fishes - South Africa - Vaal Dam - UJ Island , Metal catalysis , Inductively coupled plasma mass spectrometry
- Type: Thesis
- Identifier: uj:13656 , http://hdl.handle.net/10210/13840
- Description: MSc. (Zoology) , The use of parasites in aquatic monitoring studies has increased over the last two decades, due to the remarkable ability to accumulate metals to higher concentrations than their hosts. Studies utilizing parasitic organisms have primarily focused on the use of endoparasites, resulting in limited knowledge on the potential of ectoparasitic organisms. The present study was undertaken in April 2013 at UJ Island (26°52.249‟S; 20°10.249‟E) in the Vaal Dam where 22 Labeo capensis Smith, 1841 were collected with the aid of gill nets. All Argulus japonicus Thiele, 1900 specimens were collected off of each host upon host collection, and kept alive for 24 hours prior to being frozen, to allow for digestion of intestinum content. Water and sediment samples were collected on site, and water quality data was received from Rand Water Analytical Facility in Vereeniging for the sampling period, as this organisation routinely monitors the physico-chemical parameters and metal concentrations of the Vaal Dam. The fish were sacrificed by severing the spinal cord, and blood, gill arch, gill filament, kidney, liver, muscle and skin tissues were collected from each fish for metal analysis. All samples were frozen and transported to the University of Johannesburg for analysis. Water, fish tissue, parasite and sediment samples underwent acid digestion utilizing closed vessel microwave digestion techniques, and analysis was performed utilizing both Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) and Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES). Fish muscle tissue underwent further Cold Vapour Atomic Absorption Spectrometry (CVAAS) analysis. Selected A. japonicus specimens were prepared for fluorescence microscopy. These specimens underwent photo irradiation and were treated with Phen Green FL cell permeate diacetate stain to visually locate regions where the metals were being accumulated. The results from the metal analysis indicated that metals present within the Vaal Dam water are all at trace levels. The comparison of metal concentrations between the water, sediment and fish tissues revealed that sediment contains the highest concentrations for metals, followed by fish tissues and water at the lowest concentrations. This trend exists as a result of the underlying geological morphology of the Vaal Dam, the physiological and biological characteristics of L. capensis, and the physico-chemical variables of the water. The risk assessment performed on the muscle tissue revealed that the levels of arsenic, cadmium and selenium were above the safety threshold values for human consumption. The analysis of the A. japonicus specimens revealed that the selected techniques were not adequate for the analysis of individual specimens, as specimens were too small...
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Speciation studies of trace metals in environmental samples, using spectrometric techniques
- Authors: Nyaba, Luthando
- Date: 2016
- Subjects: Mass spectrometry , Trace elements - Speciation , Metals - Speciation , Inductively coupled plasma mass spectrometry
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/124960 , uj:20979
- Description: Abstract: Trace metals in the environmental matrices may provide benefit or risk to humans, as well as other living organisms. Normally, environmental policies regulate maximum allowed total metal concentrations that may be toxic to living organisms. However, this approach has been criticized due to failure to consider the different toxicities that occur when metals exist in different species. Therefore, it is necessary to determine the chemical forms (species) of the element, because different species of the same metal can range from essential to innocuous to toxic. Therefore, the main objective of this project is to develop sample preparation techniques for speciation of V, Mo, Se Te and Sb in environmental samples prior to spectrometric determinations. The sample preparations methods include suspended solid phase extraction (SDSPME), dispersive liquid-liquid microextraction (DLLME) and ultrasound-assisted dispersive solid phase microextraction (UADSPME). A rapid and efficient preconcentration method for speciation of Mo (VI), Sb (V) and V (V) that is based on ligandless ultrasound-assisted dispersive solid phase microextraction (UADSPME) using Fe3O4@Al2O3 nanoparticles (NPs) as a sorbent was developed. The NPs were characterized using XRD, SEM, EDX and surface area (BET). The experimental parameters affecting the preconcetration system were optimized using fractional factorial design. The target analytes quantified by inductively coupled plasma spectrometry (ICP-OES). Under optimum conditions, the developed method displayed relatively low limits of detection and quantification, good repeatability (intra-day precision) and reproducibility (inter-day precision). Finally, a non-chromatographic method was developed for speciation of Mo, Sb, and V at trace levels and successfully applied for the determination of analytes in environmental water samples. On the other hand, suspended dispersive solid phase microextraction combined with inductively coupled plasma spectrometric determination was used for speciation of inorganic selenium in water samples. Nano-alumina modified with Aliquat 336 was used as a solid phase materials. The developed method was found to be selective to Se(IV). The SDSPME procedure displayed excellent analytical figures of merit such as linearity, low LODs and LOQs, high precision and accuracy as well as high sample throughput. Dispersive liquid-liquid microextraction (DLLME) was used for speciation of tellurium in wastewater and surface water samples. A multivariate approach was used for optimization of experimental parameters affecting the speciation of Te. Under the... , M.Tech. (Chemistry)
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- Authors: Nyaba, Luthando
- Date: 2016
- Subjects: Mass spectrometry , Trace elements - Speciation , Metals - Speciation , Inductively coupled plasma mass spectrometry
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/124960 , uj:20979
- Description: Abstract: Trace metals in the environmental matrices may provide benefit or risk to humans, as well as other living organisms. Normally, environmental policies regulate maximum allowed total metal concentrations that may be toxic to living organisms. However, this approach has been criticized due to failure to consider the different toxicities that occur when metals exist in different species. Therefore, it is necessary to determine the chemical forms (species) of the element, because different species of the same metal can range from essential to innocuous to toxic. Therefore, the main objective of this project is to develop sample preparation techniques for speciation of V, Mo, Se Te and Sb in environmental samples prior to spectrometric determinations. The sample preparations methods include suspended solid phase extraction (SDSPME), dispersive liquid-liquid microextraction (DLLME) and ultrasound-assisted dispersive solid phase microextraction (UADSPME). A rapid and efficient preconcentration method for speciation of Mo (VI), Sb (V) and V (V) that is based on ligandless ultrasound-assisted dispersive solid phase microextraction (UADSPME) using Fe3O4@Al2O3 nanoparticles (NPs) as a sorbent was developed. The NPs were characterized using XRD, SEM, EDX and surface area (BET). The experimental parameters affecting the preconcetration system were optimized using fractional factorial design. The target analytes quantified by inductively coupled plasma spectrometry (ICP-OES). Under optimum conditions, the developed method displayed relatively low limits of detection and quantification, good repeatability (intra-day precision) and reproducibility (inter-day precision). Finally, a non-chromatographic method was developed for speciation of Mo, Sb, and V at trace levels and successfully applied for the determination of analytes in environmental water samples. On the other hand, suspended dispersive solid phase microextraction combined with inductively coupled plasma spectrometric determination was used for speciation of inorganic selenium in water samples. Nano-alumina modified with Aliquat 336 was used as a solid phase materials. The developed method was found to be selective to Se(IV). The SDSPME procedure displayed excellent analytical figures of merit such as linearity, low LODs and LOQs, high precision and accuracy as well as high sample throughput. Dispersive liquid-liquid microextraction (DLLME) was used for speciation of tellurium in wastewater and surface water samples. A multivariate approach was used for optimization of experimental parameters affecting the speciation of Te. Under the... , M.Tech. (Chemistry)
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Precise 87Sr/86Sr isotope ratio measurement by quadrupole based ICP-MS after ion exchange separation of Rb for provenance determination of agricultural products
- Authors: Vorster, Clarisa
- Date: 2010-04-08T08:33:41Z
- Subjects: Wine and wine making , Strontium isotopes , Inductively coupled plasma mass spectrometry , Ion exchange chromatography , Provenance trials
- Type: Thesis
- Identifier: uj:6750 , http://hdl.handle.net/10210/3158
- Description: M.Sc. , The strontium isotope ratio 87Sr/86Sr in the wine and soil of four wine-producing regions in South Africa has been determined using quadrupole ICP-MS. Isotope ratio measurements with fairly good precision had been obtained and 87Sr/86Sr ratio values in wine and soil samples were statistically evaluated to determine whether the regions investigated could be distinguished. Statistical interpretation of data revealed that the Robertson wine-producing region could be distinguished from Stellenbosch, Swartland and Walker Bay wine regions on the basis of their 87Sr/86Sr ratio. By using a combination of 87Sr/86Sr and multielement data, canonical discriminant functions with very good classification abilities could be obtained to correctly distinguish between wine and soil samples originating from a specific production region. Due to the isobaric overlap of strontium and rubidium at mass 87, a very good strontium-rubidium separation method had to be developed. The chelating properties of EDTA and DCTA in combination with ion exchange chromatography were explored in order to achieve such a separation. Due to the advanced rubidium separation ability of the developed DCTA elution method, it has been employed in all wine and soil sample preparations. Since chromatographic ion exchange procedures are not capable of removing all the rubidium from the sample matrices, 87Sr/86Sr ratio values were mathematically corrected for residual rubidium using an 88Sr correction. Since strontium isotope ratio measurements require very good precision, it is traditionally determined using TIMS. However, due to the ease of operation, shorter analysis time and widespread availability of quadrupole ICP-MS, the technique was evaluated for its merit for determining strontium isotope ratios. The optimization of acquisition parameters for the determination of the 87Sr/86Sr ratio in wine and soil samples with good precision of below 0.1% RSD has been conducted. Furthermore, selected sample matrix components were assessed as possible matrix interferences as well as for their ability to affect the precision of measurements. It was concluded that with adequate optimization of acquisition parameters, proper sample preparation and reliable mathematical correction of data, 87Sr/86Sr ratio measurements with reasonable precision could be obtained using quadrupole ICP-MS.
- Full Text:
- Authors: Vorster, Clarisa
- Date: 2010-04-08T08:33:41Z
- Subjects: Wine and wine making , Strontium isotopes , Inductively coupled plasma mass spectrometry , Ion exchange chromatography , Provenance trials
- Type: Thesis
- Identifier: uj:6750 , http://hdl.handle.net/10210/3158
- Description: M.Sc. , The strontium isotope ratio 87Sr/86Sr in the wine and soil of four wine-producing regions in South Africa has been determined using quadrupole ICP-MS. Isotope ratio measurements with fairly good precision had been obtained and 87Sr/86Sr ratio values in wine and soil samples were statistically evaluated to determine whether the regions investigated could be distinguished. Statistical interpretation of data revealed that the Robertson wine-producing region could be distinguished from Stellenbosch, Swartland and Walker Bay wine regions on the basis of their 87Sr/86Sr ratio. By using a combination of 87Sr/86Sr and multielement data, canonical discriminant functions with very good classification abilities could be obtained to correctly distinguish between wine and soil samples originating from a specific production region. Due to the isobaric overlap of strontium and rubidium at mass 87, a very good strontium-rubidium separation method had to be developed. The chelating properties of EDTA and DCTA in combination with ion exchange chromatography were explored in order to achieve such a separation. Due to the advanced rubidium separation ability of the developed DCTA elution method, it has been employed in all wine and soil sample preparations. Since chromatographic ion exchange procedures are not capable of removing all the rubidium from the sample matrices, 87Sr/86Sr ratio values were mathematically corrected for residual rubidium using an 88Sr correction. Since strontium isotope ratio measurements require very good precision, it is traditionally determined using TIMS. However, due to the ease of operation, shorter analysis time and widespread availability of quadrupole ICP-MS, the technique was evaluated for its merit for determining strontium isotope ratios. The optimization of acquisition parameters for the determination of the 87Sr/86Sr ratio in wine and soil samples with good precision of below 0.1% RSD has been conducted. Furthermore, selected sample matrix components were assessed as possible matrix interferences as well as for their ability to affect the precision of measurements. It was concluded that with adequate optimization of acquisition parameters, proper sample preparation and reliable mathematical correction of data, 87Sr/86Sr ratio measurements with reasonable precision could be obtained using quadrupole ICP-MS.
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Identification of the sources of, and subsequent minimization of the uncertainties associated with the measurement of minor elements in PGM furnace matte by ICP-MS
- Authors: Goso, Xolisa Camagu
- Date: 2009-03-31T09:23:10Z
- Subjects: Inductively coupled plasma mass spectrometry , Platinum group metallurgy
- Type: Thesis
- Identifier: uj:8239 , http://hdl.handle.net/10210/2350
- Description: M.Tech. , The Inductively Coupled Plasma Mass Spectrometry (ICP-MS) technique showed very high uncertainties associated with the determination of the concentrations of minor elements in the Platinum Group Metal (PGM) smelting plant samples. This project reports on the work done for the identification of, and subsequent minimisation of the sources of uncertainties associated with the measurements of minor elements in the PGM Furnace Matte material by ICP-MS. To perform these studies, Elan 6000, Shimadzu ICPM-8500 and Finnigan Element 2 ICP-M spectrometers were employed. Synthetic Furnace Matte samples (SFMSs) were prepared and used to ascertain the uncertainties associated with the alleged sources at Mintek and Leo-Tech laboratories. The Element 2 spectrometer dominated the other two ICP-M spectrometers in terms of the accuracy for the determination of the concentrations of minor elements in SFMSs. The evidence of spectral interferences from the significant deviations in the measurement results between the isotopes of the same element was observed in the quantification of Zn, Se, Te and Sn in SFMS by the quadrupole Elan 6000 and the Shimadzu spectrometers. It also transpired that the accuracy of the quantitative determination of minor elements in the Furnace Matte (FM) matrix by ICP-MS was hampered by the matrix elements with the severity depending on the specific analyte and the make and model of the ICP-M spectrometer. The Anglo platinum FM material that was analysed in the second round robin was used as a Certified Reference Material (CRM) in the analysis of the Lonmin FM sample. It was revealed that the laboratory standard operating procedures for the preparation, dilution and subsequent analysis of the sample are potential sources of uncertainty in measurement results. The two-fold dilution of the sample for the lessening of the matrix effects was not effective. The use of multi-walled nanotubes for the alleviation of the matrix effects by removal was also not successful. Nevertheless standard addition method (SAM), combined with internal standardisation can be used as an effective calibration method in ICP-MS to achieve less matrix interfered results over the combination of the common external standardisation and internal standardisation methods.
- Full Text:
- Authors: Goso, Xolisa Camagu
- Date: 2009-03-31T09:23:10Z
- Subjects: Inductively coupled plasma mass spectrometry , Platinum group metallurgy
- Type: Thesis
- Identifier: uj:8239 , http://hdl.handle.net/10210/2350
- Description: M.Tech. , The Inductively Coupled Plasma Mass Spectrometry (ICP-MS) technique showed very high uncertainties associated with the determination of the concentrations of minor elements in the Platinum Group Metal (PGM) smelting plant samples. This project reports on the work done for the identification of, and subsequent minimisation of the sources of uncertainties associated with the measurements of minor elements in the PGM Furnace Matte material by ICP-MS. To perform these studies, Elan 6000, Shimadzu ICPM-8500 and Finnigan Element 2 ICP-M spectrometers were employed. Synthetic Furnace Matte samples (SFMSs) were prepared and used to ascertain the uncertainties associated with the alleged sources at Mintek and Leo-Tech laboratories. The Element 2 spectrometer dominated the other two ICP-M spectrometers in terms of the accuracy for the determination of the concentrations of minor elements in SFMSs. The evidence of spectral interferences from the significant deviations in the measurement results between the isotopes of the same element was observed in the quantification of Zn, Se, Te and Sn in SFMS by the quadrupole Elan 6000 and the Shimadzu spectrometers. It also transpired that the accuracy of the quantitative determination of minor elements in the Furnace Matte (FM) matrix by ICP-MS was hampered by the matrix elements with the severity depending on the specific analyte and the make and model of the ICP-M spectrometer. The Anglo platinum FM material that was analysed in the second round robin was used as a Certified Reference Material (CRM) in the analysis of the Lonmin FM sample. It was revealed that the laboratory standard operating procedures for the preparation, dilution and subsequent analysis of the sample are potential sources of uncertainty in measurement results. The two-fold dilution of the sample for the lessening of the matrix effects was not effective. The use of multi-walled nanotubes for the alleviation of the matrix effects by removal was also not successful. Nevertheless standard addition method (SAM), combined with internal standardisation can be used as an effective calibration method in ICP-MS to achieve less matrix interfered results over the combination of the common external standardisation and internal standardisation methods.
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Multi-element analysis of South African wines and their provenance soils by ICP-MS and their classification according to geographical origin using multivariate statistics
- Authors: Van der Linde, Gert
- Date: 2010-04-08T08:45:39Z
- Subjects: Wine and wine making , Inductively coupled plasma mass spectrometry , Provenance trials , Trace elements
- Type: Thesis
- Identifier: uj:6766 , http://hdl.handle.net/10210/3172
- Description: M.Sc. , The South African wine industry is well respected internationally for producing high quality wines. The possible adulteration of these wines can lead to loss of reputation and a loss of sales and could also be dangerous to consumer’s health. Multi-element analysis of wines is one way of implementing quality control and the same multi-element data can also be used to prove the point of origin. The metal content of the fruit (grapes) should represent the metal content of the soil in which the plants (vineyards) were grown. An Inductively Coupled Plasma Mass Spectrometer (ICP-MS) was used with correct internal standard and interference correction to obtain reliable concentrations for 27 elements (Li, B, Al, Sc, V, Cr, Mn, Co, Ni, Cu, Zn, Se, Rb, Sr, Zr, Nb, Mo, Cd, Sn, Sb, Ba, Ce, Nd, W, Tl, Pb and U) of 1:1 diluted wines and microwave digested vineyard soil from four South-African wine-producing regions: Stellenbosch, Swartland, Robertson and Walker Bay. This multi-element data was then interpreted using multivariate statistical analysis in order to determine which elements have the ability to discriminate between the four regions. Li, B, Sc, Ni, Mn, Co, Cu, and Rb were the elements that were identified to have discrimination ability. 96% of wines and 100% of vineyard soils were correctly classified. Indirectly it has been proven that the metal content of the soil can be correlated to the metal content of the wine. This methodology can be reliably used in industry for quality control and routine provenance determination
- Full Text:
- Authors: Van der Linde, Gert
- Date: 2010-04-08T08:45:39Z
- Subjects: Wine and wine making , Inductively coupled plasma mass spectrometry , Provenance trials , Trace elements
- Type: Thesis
- Identifier: uj:6766 , http://hdl.handle.net/10210/3172
- Description: M.Sc. , The South African wine industry is well respected internationally for producing high quality wines. The possible adulteration of these wines can lead to loss of reputation and a loss of sales and could also be dangerous to consumer’s health. Multi-element analysis of wines is one way of implementing quality control and the same multi-element data can also be used to prove the point of origin. The metal content of the fruit (grapes) should represent the metal content of the soil in which the plants (vineyards) were grown. An Inductively Coupled Plasma Mass Spectrometer (ICP-MS) was used with correct internal standard and interference correction to obtain reliable concentrations for 27 elements (Li, B, Al, Sc, V, Cr, Mn, Co, Ni, Cu, Zn, Se, Rb, Sr, Zr, Nb, Mo, Cd, Sn, Sb, Ba, Ce, Nd, W, Tl, Pb and U) of 1:1 diluted wines and microwave digested vineyard soil from four South-African wine-producing regions: Stellenbosch, Swartland, Robertson and Walker Bay. This multi-element data was then interpreted using multivariate statistical analysis in order to determine which elements have the ability to discriminate between the four regions. Li, B, Sc, Ni, Mn, Co, Cu, and Rb were the elements that were identified to have discrimination ability. 96% of wines and 100% of vineyard soils were correctly classified. Indirectly it has been proven that the metal content of the soil can be correlated to the metal content of the wine. This methodology can be reliably used in industry for quality control and routine provenance determination
- Full Text:
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