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Óleo essencial de casca-preciosa (Aniba canelilla (H. B. K. ) Mez) : validação de metodologia bioanalítica e estudo de permeação cutânea in vitro / “Precious-bark” essential oil (Aniba canelilla (H. B. K.) Mez) : bioanalytical method validation and in vitro cutaneous permeation studyKreutz, Tainá January 2017 (has links)
A Aniba canelilla (H.B.K.) Mez é uma planta aromática proveniente da região amazônica cujo óleo essencial apresenta como componentes majoritários o 1-nitro-2-feniletano e o metileugenol. Apesar das atividades antifúngicas e anti-inflamatórias cientificamente comprovadas e do uso popular do óleo para o tratamento de dermatites, acnes e feridas, não existe até o momento um estudo que verse sobre a quantificação desses compostos na pele. O objetivo deste trabalho foi a validação de um método bioanalítico otimizado por microextração em fase sólida no modo headspace em cromatógrafo gasoso com detector de ionização de chama (HS-SPME-GC-FID) para a determinação do 1-nitro-2-feniletano e metileugenol a partir do óleo essencial em diferentes amostras de estudo de permeação cutânea in vitro. Uma metodologia foi desenvolvida e validada por HS-SPME-GC-FID. A faixa da curva de calibração foi de 2,08 - 207,87 μg.mL-1 para o 1-nitro-2-feniletano e de 0,40-40,41 μg.mL-1 para o metileugenol. A presença de matriz e as características intrínsecas da metodologia de HS-SPME requereram uma transformação da curva de calibração. A transformação logarítmica (Log10) foi então aplicada aos dados e os resultados apresentaram homocedasticidade, resíduos dispersos, coeficiente de determinação (r²> 0,99) e recuperação adequados. Estudos de permeação cutânea foram realizados em células de Franz com diferentes quantidades (20, 100 e 200 μL) de óleo essencial de A. canelilla para avaliar o perfil de permeação e retenção em pele de orelha suína e fluido receptor. A análise das amostras nas condições validadas mostrou uma grande permeação e retenção dos compostos na seguinte ordem: fluido receptor >> derme >> epiderme >> estrato córneo. Verificou-se um aumento progressivo e dependência na retenção com base na quantidade aplicada no compartimento doador e grande retenção principalmente no fluido receptor e derme, resultado este compatível com as características físico-químicas de Log P, afinidade ao ambiente hidrofílico e lipofílico, tamanho e peso molecular do 1-nitro-2-feniletano e metileugenol. Em conclusão, o método proposto por HS-SPME-GC-FID para quantificar os compostos majoritários do óleo essencial de A. canelilla em amostras de pele de orelha suína e fluido receptor foi seletivo, preciso, exato e adequado, e pode ser utilizado em análises futuras. / Aniba canelilla (H.B.K.) Mez is an aromatic plant from the Amazon region whose essential oil has 1-nitro-2-phenylethane and methyleugenol as major compounds. Despite of the scientifically proved antifungal and anti-inflammatory activities and the popular use of oil for the treatment of dermatitis, acnes and wounds, there is no study up to date about the quantification of these compounds in skin samples. The aim of this study was the validation of an optimized bioanalytical method by solid phase microextraction on headspace mode in gas chromatograph with flame ionization detector (HS-SPME-GC-FID) for the determination of 1-nitro-2-phenylethane and methyleugenol from the essential oil in different samples of in vitro cutaneous permeation study. A methodology was developed and validated by HS-SPME-GC-FID. The ranges of calibration curves were 2.08 - 207.87 μg.mL-1 for 1-nitro-2-phenylethane and 0.40 - 40.41 μg.mL-1 for methyleugenol. The presence of matrix and the intrinsic characteristics of the HS-SPME methodology required a transformation to the calibration curves. The logarithmic transformation (Log10) was then applied to the data and the results showed homoscedasticity, dispersed residues, and adequate coefficient of determination (r²> 0.99) and recovery. Skin permeation studies were performed on Franz cells with different amounts (20, 100 and 200 μL) of A. canelilla essential oil to evaluate the skin permeation and retention profile in porcine ear skin and receptor fluid. The analysis of the samples under the validated conditions showed a high permeation and retention of the major compounds in the following order: receptor fluid >> dermis >> epidermis >> stratum corneum. A progressive increase and retention dependence were observed based on the amount applied in the donor compartment, and large retention mainly on the receptor fluid and dermis was observed, in accordance with the physicochemical characteristics of Log P, affinity to the hydrophilic and lipophilic environment, size and molecular weight of 1-nitro-2-phenylethane and methyleugenol. In conclusion, the method proposed by HS-SPME-GC-FID to quantify the major compounds of A. canelilla essential oil in porcine ear skin and receptor fluid samples was selective, accurate, precise and adequate, and can be used in future analyzes.
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The Detection of an Invasive Pathogen through Chemical and Biological Means for the Protection of Commercial CropsSimon, Alison G 22 September 2017 (has links)
Standoff detection of targets using volatiles is essential when considering substances that are hazardous or dangerous, or for which the presence or location is unknown. For many invasive biological threats, their presence is often not realized until they have begun visibly affecting and spreading through crops or forests. The fungus Raffaelea lauricola is a biothreat vectored by the invasive beetle Xyleborus glabratus, or redbay ambrosia beetle (RAB), whose presence in avocado groves is currently detectable by visual inspection. Once visually identified, the affected trees must be removed and destroyed to protect those remaining trees. However, if the fungus is identified via standoff volatile detection, there is anecdotal evidence that it can be treated with propiconazole and saved from progression to the fatal laurel wilt disease. As a result of the rapid spread of R. lauricola and the quick death of trees, early detection through standoff methods is essential. The only current method of pre-symptomatic identification is canine detection. Canines are sensitive and selective biological detectors that can trace odors to their source, despite the presence of a variety of background odors. The present research evaluated the volatile organic compounds (VOCs) of the laurel wilt disease and R. lauricola using headspace solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). Additionally, a new method for odor collection and presentation to trained detection canines was developed. Knowledge of the disease and standoff volatile detection capabilities are improved using this information.
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Effects of the Cyanobacterium Nodularia spumigena on Selected Estuarine FaunaDavies, Warren Raymond, warren.davies@optusnet.com.au January 2007 (has links)
Nodularia spumigena is an estuarine cyanobacteria that produces the toxin nodularin. This toxic cyanobacteria is known to have caused death to domestic and wild animals and is recognised as dangerous to human health. N. spumigena causes harmful algal blooms in many parts of the world including Australia. The toxic solutes of N. spumigena are potentially dangerous when contact is made to contaminated water bodies or is ingested by primary consumers. In Australia blooms of N. spumigena are common in the Gippsland Lakes in South-eastern Victoria and cause socio - economic hardships to the local communities. This PhD investigates the toxic effects of N. spumigena and its solutes to a range of aquatic life. A method known as SPME - HPLC showed promise in environmental monitoring of N. spumigena toxins by measuring nodularin from water samples. Other research presented study into the lethal and sublethal effects of on an extract from N. spumigena to aquatic fauna. Resu lts showed the N. spumigena extract was not lethal to many aquatic fauna although zooplankton from the Gippsland Lakes showed mortality at environmental relevant levels. Biochemical studies focusing on animal detoxification and antioxidation enzymes and DNA integrity showed sublethal effects to the N. spumigena extract. Results presented in this thesis show that an extract of N. spumigena elicited detoxification and antioxidation responses in animals tested. Furthermore, the use of the COMET assay showed increased damage to DNA of animals tested. Results also showed that different organs in animals tested responded differently to the aqueous extract, suggesting mode of uptake maybe important in toxicosis. Further, feeding studies with N. spumigena help elucidate mode of uptake using enzyme response biomarkers. The overall results of this research provided an assessment of the toxic affects of N. spumigena on aquatic fauna with special reference to the Gippsland Lakes, Victoria, Australia.
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Mise au point d'une méthodologie d'échantillonnage utilisant la micro-extraction sur phase solide pour la quantification de goudrons sur des procédés de thermolyse de la biomasseComte, Julien 31 October 2008 (has links) (PDF)
La gazéification de la biomasse par voie thermochimique apparaît aujourd'hui comme une voie prometteuse pour la production de H2 et CO utilisés dans la synthèse de biocarburants. Le traitement thermique subi par la biomasse entraîne toutefois la production de composés indésirables appelés goudrons (hydrocarbures lourds) dont la teneur dans les gaz de synthèse doit être inférieure à 0,1 mg.Nm-3. Le suivi de la quantité de goudrons produits est, par conséquent, indispensable. Dans ce contexte, une méthodologie d'échantillonnage utilisant la SPME (micro-extraction sur phase solide) a été mise au point pour la quantification de "composés types" représentatifs de la quantité globale de goudrons émis principalement par deux pilotes de gazéification et de pyrolyse. L'introduction de la notion de composés types est destinée d'une part, à simplifier la méthodologie d'échantillonnage et d'autre part, à s'affranchir des éventuelles limitations liées au système de prélèvement des effluents gazeux développé dans le cadre de ce travail pour autoriser l'extraction par SPME. Pour les deux pilotes, 15 composés types ont été retenus. Leur quantification a d'abord nécessité l'étalonnage préalable des fibres SPME (revêtue de polydimethylsiloxane) qui a permis, à plusieurs températures, d'établir les profils d'absorption et de déterminer les coefficients de partage. L'influence des conditions d'extraction sur l'absorption ainsi que les performances du couplage SPME-chromatographie gazeuse ont également été évaluées. De manière à éviter les étalonnages répétitifs, un modèle basé sur la théorie des équilibres thermodynamiques a été développé pour déterminer la valeur des coefficients de partage.
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The effect of wine matrix on the analysis of volatile sulfur compounds by solid-phase microextraction-GC-PFPDDavis, Peter M. (Peter Mathew) 30 March 2012 (has links)
Constituents of the wine matrix, including ethanol, affect adsorption of sulfur volatiles on solid-phase microextraction (SPME) fibers, which can impact sensitivity and accuracy of volatile sulfur analysis in wine. Several common wine sulfur volatiles, including hydrogen sulfide (H2S), methanethiol (MeSH), dimethyl sulfide (DMS), dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS), diethyl disulfide (DEDS), methyl thioacetate (MeSOAc), and ethyl thioacetate (EtSOAc), have been analyzed with multiple internal standards using SPME-GC equipped with pulsed-flame photometric detection (PFPD) at various concentrations of ethanol, volatile-, and non-volatile-matrix components in synthetic wine samples. All compounds exhibit a stark decrease in detectability with the addition of ethanol, especially between 0.0 and 0.5%v/v, but the ratio of standard to internal standard was more stable when alcohol concentration was greater than 1%. Addition of volatile matrix components yields a similar decrease but the standard-to-internal-standard ratio was consistent, suggesting the volatile matrix did not affect the quantification of volatile sulfur compounds in wine. Non-volatile wine matrix appears to have negligible effect on sensitivity. Based on analyte:internal standard ratios, DMS can be accurately measured against ethyl methyl sulfide (EMS), the thioacetates and DMDS with diethyl sulfide (DES), and H₂S, MeSH, DEDS, and DMTS with diisopropyl disulfide (DIDS) in wine with proper dilution. The developed method was then used to quantify sulfur compounds in 21 various California wines. H₂S and MeSH were found in higher concentrations in white varietals, while DMS was slightly higher in red varietals, particularly cabernet sauvignon and merlot. Trace amounts of DEDS and MeSOAc were found in almost all wines. DMS and DMTS were found in all wines, in some instances above reported thresholds. / Graduation date: 2012
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Solid-phase Microextraction and Detection of Organophosphate Triesters in Indoor airIsetun, Sindra January 2004 (has links)
In the work underlying this thesis solid-phase microextraction (SPME) was evaluated as a passive sampling technique for organophosphate triesters in indoor air. These compounds are used on a large scale as flame-retarding and plastizicing additives in a variety of materials and products, and have proven to be common pollutants in indoor air. The main objective of this work was to develop an accurate method for measuring the volatile fraction. Such a method can be used in combination with active sampling to obtain information regarding the vapour/particulate distribution in different indoor environments. SPME was investigated under both equilibrium and non-equilibrium conditions and parameters associated with these different conditions were estimated. In <b>Paper I</b>, time-weighted average (TWA) SPME under dynamic conditions was investigated in order to obtain a fast air sampling method for organophosphate triesters. Among the investigated SPME coatings, the absorptive PDMS polymer had the highest affinity for the organophosphate triesters and was consequently used in all further work. Since the sampling rate is dependent on the agitation conditions, the linear airflow rates had to be carefully considered. Sampling periods as short as 1 hour were shown to be sufficient for measurements in the ng-μg m-3 range when using a PDMS 100-μm fibre and a linear flow rate above 7 cm s-1 over the fibre. SPME under equilibrium conditions is rather time-consuming, even under dynamic conditions, for slowly partitioning compounds such as organophosphate triesters. Nevertheless, this method has some significant advantages. For instance, the limit of detection is much lower compared to 1 h TWA sampling. Furthermore, the sampling time can be ignored as long as equilibrium has been attained. In <b>Paper II</b>, SPME under equilibrium conditions was investigated and evaluated for organophosphate triester vapours. Since temperature and humidity are closely associated with the distribution constant a simple study of the effect of these parameters was performed. The obtained distribution constants were used to determine the air levels in a common indoor environment. SPME and parallel active sampling on filters yielded similar results, indicating that the detected compounds were almost entirely associated with the vapour phase To apply dynamic SPME method in the field a sampler device, which enables controlled linear airflow rates to be applied, was constructed and evaluated (<b>Paper III</b>). This device was developed for application of SPME and active sampling in parallel. A GC/PICI-MS/MS method was developed and used in combination with active sampling of organophosphate triesters in indoor air (<b>Paper IV</b>). The combination of MS/MS and the soft ionization achieved with methanol as reagent gas yielded high selectivity and detection limits comparable to those provided by GC with nitrogen-phosphorus detection (NPD). The method limit of detection, when sampling 1.5 m3 of air, was in the range 0.1-1.4 ng m-3. In <b>Paper V</b>, the developed MS method was used in combination with SPME for indoor air measurements. The levels detected in the investigated indoor environments range from a few ng to μg m-3. Tris(2-chloropropyl) phosphate was detected at a concentration as high as 7 μg m-3 in a newly rebuilt lecture room.
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Microwave extraction of essential oils (from black pepper and coriander) at 2.46 GHzRamanadhan, Balasundaram 27 October 2005
Essential oils are composed of a wide range of bioactive chemical compounds. They traditionally found application as flavour, fragrances and medicinal aroma. Today, the essential oils are sought-after for innumerable applications starting from markers for plant identifications to base for semi-synthesis of highly complex molecules. The extraction of highly delicate essential oils from plants remains a crucial step in all these applications. By using microwaves to mediate the extraction, it is possible to maintain mild conditions and effect superior extraction. However, apart from laboratory trials, essential oil extraction using microwave energy is largely an unexplored area. In the current work, an integrated procedure for microwave extraction followed by volatiles sampling and analysis from selected botanical raw materials (viz. black pepper, Piper nigrum and coriander Coriandrum sativum) was developed. There are two problems to overcome in the extraction from solid plant materials: that of releasing the essential oil from solid matrix and letting it diffuse out successfully in a manner that can be scaled-up to industrial volumes. Towards this end, an innovative volatiles extraction unit was conceived, designed and developed that used thin layer, for microwave exposure and rotational mixing, to mitigate the effects of thermal gradient and non-uniform exposure of bulk matter.
The effect of varying the microwave field on the essential oils extracted was studied. The microwave field that coupled in the region of extraction was estimated from temperature rise measurement using the microwave power equation (with water as reference dielectric). The essential oil extracted under different microwave fields were compared using gas chromatography-mass spectrometry (GC-MS) and data analysis with SAS statistical software.
The microwave field at the site of extraction was sensed by symmetrical placement of biomaterial sample and a reference, in a rotational extractor, such that they both couple the same field during tumbling motion. By measuring the temperature rise in the reference accurately, it is possible to estimate the microwave field present at that position. The rotational extractor has a second degree of freedom, in that it can slide along the axel taking discrete positions. Each position leads to a different microwave exposure of the sample. It is possible to measure the relative variation of microwave field using temperature rise data at each position. It was found that, at position labeled R4, located at 65.6 mm from the right extreme of the microwave cavity had the highest effective microwave field strength of value 92.7 V/m.
The volatiles released from the biomaterials, black pepper and coriander, were sampled using solid phase micro extraction and analyzed using gas chromatography-mass spectrometry. The highest peaks representing beta-caryophyllene in black pepper and linalool in coriander were identified using mass spectrometric peak matching using NIST library.The extract (in terms of ion count) for each microwave parameter (such as field, water content level and solvent type) was plotted as a trend graph.
The current experiment successfully tested the procedure for following the microwave process in the extraction of sensitive spice volatiles (from black pepper and coriander). With the microwave field measured at the region of extraction, it was possible to plot pepper extraction versus the microwave field to which the pepper sample was exposed. The extraction was represented in terms of cumulative value of ion counts obtained in GC-MS analysis. This unique procedure developed in the current research allows for the graphical comparison of the microwave extractions. It was found that black pepper has a better response to microwave extraction than coriander. The pepper extraction was found to increase proportionately with increase in microwave field strength. The extraction was also enhanced proportionately by the incremental addition of water content at constant microwave field.
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In Vivo Detection of Trace Organic Contaminants in Fish Using Solid Phase MicroextractionWang, Shuang 18 October 2010 (has links)
The feasibility of using solid phase micro-extraction (SPME) as an in vivo sampling tool for analysis of trace environmental contaminants in fish exposed to municipal wastewater effluents (MWWEs) was validated using controlled laboratory and field experiments. SPME was compared with traditional extraction techniques, including solid phase extraction (SPE) in water and solid-liquid extraction (SLE) in fish tissues to assess relative efficiencies. All three techniques were used to quantify the presence of eight compounds of interest in fish exposed to MWWEs in the laboratory, as well as in wild and field caged fish upstream and downstream of three wastewater treatment plants in the Grand River watershed. Atrazine, carbamazepine, naproxen, diclofenac, gemfibrozil, bisphenol A, fluoxetine and ibuprofen were selected as target compounds due to their diverse chemical characteristics and frequent detection in surface waters and sediments around the world. The distribution coefficients between various sample matrices (water, fish) and extraction phases (SPME fibers) were compared, as were extraction profiles and bioconcentration factors of target analytes in muscle of fish exposed to MWWEs under laboratory conditions, during field caging studies, or collected (wild) from the Grand River. Poly(dimethylsiloxane) (PDMS) medical grade tubing was utilized as the SPME extraction phase, which when kinetically calibrated, were effective at extracting and quantifying the target analytes from both water and fish tissue relative to traditional techniques. Caged and in wild fish exposed to MWWEs from all three municipal treatment plants bio-accumulated detectable levels of several of the target chemicals. All target analytes (except for fluoxetine) were identified in the MWWEs and exposed fish by SPME at low concentrations (ng/L). The presence and concentration of the targeted analytes in both water and wild fish living in the Grand River watershed varied with season and proximity to the wastewater outfalls. Results demonstrate that properly applied SPME can detect and quantify selected contaminants in fish tissues, surface water, and wastewater effluents. In vivo SPME allows for non-lethal sampling of fish, which creates the opportunity for monitoring contaminant exposure in receiving environments influenced by MWWEs or non-point-source runoff while minimizing the impact on the organisms.
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Solid phase microextraction for in vivo determination of pharmaceuticals in fish and wastewaterTogunde, Oluranti Paul January 2012 (has links)
This thesis describes the development and application of solid phase microextraction (SPME) as a sample preparation technique for in vivo determination of pharmaceutical residues in fish tissue and wastewater. The occurrence, distribution and fate of pharmaceuticals in the environment are a subject of concern across the globe due to the impact they may have on human life and aquatic organisms. To address this challenge from an analytical perspective, a simplified and reliable analytical methodology is required to investigate and determine the concentration (bioconcentration factors) of trace pharmaceutical residue in fish tissue and environmental water samples (exposure). An improved SPME method, coupled with liquid chromatography with tandem mass spectrometry has been developed and applied to both controlled laboratory and field-caged fish exposed to wastewater effluent for quantitative determination of pharmaceutical residue in fish specific tissue.
A new SPME configuration based on C18 thin film (blade) was developed and optimized to improve SPME sensitivity for in vivo determinations of trace pharmaceuticals in live fish. The C18 thin film extraction phase successfully quantified bioconcentrated fluoxetine, venlafaxine, sertraline, paroxetine, and carbamazapine in the dorsal-epaxial muscle of living fish at concentrations ranging from 1.7 to 259 ng/g. The reproducibility of the method in spiked fish muscle was 9-18% RSD with limits of detection and quantification ranging from 0.08 - 0.21 ng/g and 0.09 - 0.64 ng/g (respectively) for the analytes examined. Fish were sampled by in vivo SPME for 30 min to detect pharmaceutical uptake and bioconcentration, with experimental extracts analyzed using liquid chromatography coupled with tandem mass spectrometry.
In addition, a simplified analytical methodology based on SPME was developed and optimized for determination and bioconcentration factor of different classes of pharmaceuticals residues in fish bile. The reproducibility of the method in spiked fish Rainbow Trout bile was 3-7% RSD with limits of detection (LOD) ranging from 0.3 – 1.4 ng/mL for the analytes examined. The field application of SPME sampling was further demonstrated in Fathead Minnow (Pimephales promelas), a small-bodied fish caged upstream and downstream of a local wastewater treatment plant where fluoxetine, atorvastatin, and sertraline were detected in fish bile at the downstream location. Also, a simple automated analytical method using high throughput robotic system was developed for the simultaneous extraction of pharmaceutical compounds detected in surface waters. The proposed method successfully determined concentrations of carbamazepine, fluoxetine, sertraline, and paroxetine in treated effluent at concentrations ranging from 240 - 3820 ng/L with a method detection limit of 2-13 ng/L, and a relative standard deviation of less than 16%. Application of the method was demonstrated using wastewater from pilot-scale municipal treatment plants and environmental water samples from wastewater-dominated reaches of the Grand River (Waterloo, ON).
Finally, 4 and 8-d laboratory exposures were carried out with Rainbow Trout exposed to wastewater effluent collected from pilot scale at Burlington, ON. Additionally, wild fish, White Sucker (Catostomus commersonii) were collected and sampled from Waterloo and Kitchener downstreams containing local municipal effluent. Bioconcentration factors of the selected compounds were determined in both fish muscle and bile samples. The results show that anti-depressant drugs such fluoxetine, sertraline and paroxetine were uptake in the fish muscle and fish bile for both laboratory and field exposure. In summary, exposure of fish to micro-pollutants such as pharmaceuticals may be monitored through the analysis of bile, particularly at low concentration exposure of pharmaceuticals, where the sensitivity of analytical method may be challenged. SPME is a promising simple analytical tool which can potentially be used for monitoring of pharmaceuticals in fish tissue and wastewater.
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Microwave extraction of essential oils (from black pepper and coriander) at 2.46 GHzRamanadhan, Balasundaram 27 October 2005 (has links)
Essential oils are composed of a wide range of bioactive chemical compounds. They traditionally found application as flavour, fragrances and medicinal aroma. Today, the essential oils are sought-after for innumerable applications starting from markers for plant identifications to base for semi-synthesis of highly complex molecules. The extraction of highly delicate essential oils from plants remains a crucial step in all these applications. By using microwaves to mediate the extraction, it is possible to maintain mild conditions and effect superior extraction. However, apart from laboratory trials, essential oil extraction using microwave energy is largely an unexplored area. In the current work, an integrated procedure for microwave extraction followed by volatiles sampling and analysis from selected botanical raw materials (viz. black pepper, Piper nigrum and coriander Coriandrum sativum) was developed. There are two problems to overcome in the extraction from solid plant materials: that of releasing the essential oil from solid matrix and letting it diffuse out successfully in a manner that can be scaled-up to industrial volumes. Towards this end, an innovative volatiles extraction unit was conceived, designed and developed that used thin layer, for microwave exposure and rotational mixing, to mitigate the effects of thermal gradient and non-uniform exposure of bulk matter.
The effect of varying the microwave field on the essential oils extracted was studied. The microwave field that coupled in the region of extraction was estimated from temperature rise measurement using the microwave power equation (with water as reference dielectric). The essential oil extracted under different microwave fields were compared using gas chromatography-mass spectrometry (GC-MS) and data analysis with SAS statistical software.
The microwave field at the site of extraction was sensed by symmetrical placement of biomaterial sample and a reference, in a rotational extractor, such that they both couple the same field during tumbling motion. By measuring the temperature rise in the reference accurately, it is possible to estimate the microwave field present at that position. The rotational extractor has a second degree of freedom, in that it can slide along the axel taking discrete positions. Each position leads to a different microwave exposure of the sample. It is possible to measure the relative variation of microwave field using temperature rise data at each position. It was found that, at position labeled R4, located at 65.6 mm from the right extreme of the microwave cavity had the highest effective microwave field strength of value 92.7 V/m.
The volatiles released from the biomaterials, black pepper and coriander, were sampled using solid phase micro extraction and analyzed using gas chromatography-mass spectrometry. The highest peaks representing beta-caryophyllene in black pepper and linalool in coriander were identified using mass spectrometric peak matching using NIST library.The extract (in terms of ion count) for each microwave parameter (such as field, water content level and solvent type) was plotted as a trend graph.
The current experiment successfully tested the procedure for following the microwave process in the extraction of sensitive spice volatiles (from black pepper and coriander). With the microwave field measured at the region of extraction, it was possible to plot pepper extraction versus the microwave field to which the pepper sample was exposed. The extraction was represented in terms of cumulative value of ion counts obtained in GC-MS analysis. This unique procedure developed in the current research allows for the graphical comparison of the microwave extractions. It was found that black pepper has a better response to microwave extraction than coriander. The pepper extraction was found to increase proportionately with increase in microwave field strength. The extraction was also enhanced proportionately by the incremental addition of water content at constant microwave field.
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