Master of Science / Department of Animal Sciences and Industry / Jim L. Nelssen / Five-hundred and four barrows and gilts were used in four experiments to determine the influence of dietary ingredients on fat quality. Experiment 1 evaluated feeding duration of choice white grease (CWG) and soybean oil. Increasing feeding duration of pigs fed CWG or soybean oil increased (quadratic, P < 0.01) iodine value (IV) in jowl fat and backfat. Pigs fed soybean oil had increased (P < 0.01) IV in jowl and backfat compared with pigs fed CWG. In Exp. 2 dried distillers grains with solubles (DDGS), extruded expelled soybean meal (EESM), and CWG were used to evaluate diets with common iodine value product (IVP) from ingredients varying in unsaturated fat level and concentration. Pigs fed either diet with DDGS had increased (P = 0.02) backfat and jowl fat IV, compared with all other treatments. Pigs fed EESM had increased (P = 0.04) backfat and jowl fat IV compared with the control, low CWG, and high CWG. Pigs fed low CWG and high CWG had increased (P = 0.04) jowl fat IV compared to the control. Increasing dietary fat increased carcass fat IV, with unsaturated fats from DDGS and EESM having a greater affect than more saturated fats, such as CWG, even when formulated to the same IVP. Experiment 3 evaluated the effects of increasing CWG in corn- and sorghum-based diets on fat quality. There was a grain source X fat level interaction (P = 0.04) for IV in both backfat and jowl fat. Adding CWG increased IV in backfat and jowl fat for pigs fed corn- and sorghum-based diets; however, the greatest increase was between 0 and 2.5% CWG in sorghum-based diets and between 2.5 and 5% CWG in corn-based diets. Despite this interaction, pigs fed corn-based diets had increased (P < 0.01) backfat and jowl fat IV compared with pigs fed sorghum-based diets. Increasing CWG increased (linear, P < 0.01) IV in backfat and jowl fat. Experiment 4 examined the effects of DDGS on fat quality. Backfat, jowl fat, and belly fat IV increased (linear, P = 0.02) with increasing DDGS in both the pigs marketed on d 57 and 78.

Doctor of Philosophy / Department of Animal Science / Jim L. Nelssen and Michael D. Tokach / The optimum sampling method swine producers should use to estimate the mean and SD of pig BW within a barn was determined based upon both the time required to conduct and the precision and accuracy of each sampling method. Weighing 5 pigs from 15 pens was determined to be the optimal sampling method. This should require approximately 55 min to complete. Weighing 5 pigs from 15 pens had a CI range of 7.2 to 8.0 kg for estimating the mean BW and 5.6 kg for estimating SD. Next, a meta-analysis was conducted using data from existing literature to generate equations to predict finishing pig back, belly, and jowl fat iodine value. While numerous factors were evaluated, dietary essential fatty acids, dietary net energy content, and backfat thickness had the greatest influence on predicting iodine value of the 3 distinct fat depots. Lastly, 6 experiments were conducted to determine the effects of added Zn on growth performance, pork quality, plasma Zn, and ileal mucosal inflammation mRNA expression of finishing pigs fed diets containing ractopamine-HCl (RAC; Elanco Animal Health, Greenfield, IN). Additional Zn increased plasma Zn and reduced relative expression of IL-1β, but did not improve growth performance of pigs fed diets containing RAC in 5 of the experiments. However, in 1 of the experiments, adding Zn to diets containing RAC resulted in a trend for improved growth performance of pigs. Supplementing the RAC diets with dietary Zn decreased the percentage of type IIA fibers and tended to increase the percentage of type IIX fibers compared to pigs fed the RAC diet without added Zn. Ractopamine-HCl produced chops that were lighter and less red, but possessed reduced metmyoglobin reducing ability at the end of the display period. However, adding Zn to RAC diets increased metmyoglobin reducing ability levels at the end of the display period.

Doctor of Philosophy / Department of Animal Sciences and Industry / Mike Tokach / In 11 experiments, 7,325 pigs were used to determine the effects of: 1) diet type and form on finishing pig growth performance and carcass fat iodine value (IV); 2) pellet quality and feeder adjustment on pig growth performance; 3) corn particle size and diet form on finishing pig growth performance and carcass characteristics; and 4) dietary acidification, diet complexity, and feed-grade antibiotics on nursery pig growth performance. Feeding diets with wheat middlings and dried distillers grains with solubles all the way until marketing decreased G:F and carcass yield, and worsened carcass fat IV. Withdrawing these ingredients 17 d prior to market restored carcass yield, but resulted in small improvements in IV. Pelleting diets improved growth performance; however, a novel finding is that pelleting diets fed to finishing pigs increased belly fat IV. Feeding nursery pigs from a wide feeder gap may improve ADG and ADFI, with no negative effects on G:F. For finishing pigs, reducing feeder gap reduced feed disappearance and improved G:F. In all experiments, feeding pelleted diets improved G:F, but the greatest improvements occurred when the percentage of fines was minimized. Grinding corn finer than 650 microns decreased ADFI and improved G:F for finishing pigs fed meal diets, but not for pigs fed pelleted diets. Pelleting diets improved ADG and G:F, but the greatest magnitude of G:F improvement to pellets occurred when pigs were fed diets containing the largest particle size corn. Thus, grinding corn finer than 650 microns improved feed efficiency for finishing pigs fed meal diets, but provided no additional benefit for pigs fed pelleted diets. When dietary supplementation of benzoic acid was evaluated, added benzoic acid in nursery pig diets did not influence growth performance in university conditions, whereas feeding complex diets or antimicrobials improved growth. In the commercial setting, acidifiers improved growth in one experiment but not the other. The varying response to acidifiers is likely influenced by health status, age, or starting weight of pigs.

Master of Science / Department of Animal Sciences and Industry / Robert Goodband / Three experiments used 1,756 pigs to evaluate the effects of corn dried distillers grains with solubles (DDGS) varying in oil content on growth performance, carcass characteristics, and fat quality in growing-finishing pigs. A fourth experiment used 12 pigs and determined the energy concentration and nutrient digestibility of the DDGS sources used in the previous 3 growth studies. Lastly, a fifth experiment used 576 pigs to determine the effects of DDGS and wheat middlings (midds) withdrawal 24 d before harvest in diets without or with ractopamine HCl (RAC) on growth performance, carcass characteristics, fat quality, and organ/intestine weights. Experiment 1 determined that increasing 7.4% oil DDGS decreased (linear, P < 0.02) ADG and G:F. Also, final BW, HCW, and carcass yield decreased (linear, P < 0.03), but jowl iodine value (IV) increased (linear, P < 0.001) as DDGS increased. Experiments 2 and 3 utilized DDGS sources that contained 5.2 vs. 9.3, and 9.2 vs. 11.8% oil, respectively. In brief, results suggested that while ADG was unaffected, feeding DDGS with 5.2% oil reduced G:F. In Exp. 4, stepwise regression was used to develop prediction equations based to determine that a 1% change in oil content of DDGS will change the DE by 71 kcal/kg and NE by 118 kcal/kg. Experiment 5 determined that pigs fed corn-soy (CS) diets throughout the finishing phase had greater (P < 0.03) ADG, G:F, and carcass yield and lower (P < 0.01) IV than those fed high fiber (HF; DDGS and wheat midds) diets throughout, with pigs fed the fiber withdrawal intermediately. Pigs fed RAC had greater (P < 0.01) ADG, G:F, and carcass yield than pigs not fed RAC. Iodine values were lowest (P < 0.01) for pigs fed the CS diets, highest (P < 0.01) for those fed HF diets throughout, and intermediate for pigs fed the withdrawal diet. Withdrawal of the HF diet to a CS diet partially mitigated negative effects on carcass yield and IV, and feeding RAC, regardless of dietary fiber regimen, improved growth performance and carcass yield.

A presente dissertação apresenta os resultados referentes ao desenvolvimento de procedimentos analíticos para a determinação de índice de iodo em biodiesel e óleo vegetal e do teor de éster em biodiesel e em misturas biodiesel:diesel. O primeiro procedimento para a determinação de índice de iodo foi baseado na descoloração de uma solução de I3- monitorada por espectrofotometria. Para amostras de biodiesel e óleo vegetal, foram obtidas respostas lineares nos intervalos de 10-106 g I2/100 g e 20-144 g I2/100 g, respectivamente. O coeficiente de variação (n = 10) e o limite de detecção (99,7% nível de confiança) foram estimados em 5,0% e 2,5 g I2/100 g para amostras de biodiesel, enquanto para amostras de óleos vegetais os valores foram 3,0% e 7 g I2/100 g, respectivamente. Foram consumidos ca. 1,2 mL de amostra, 0,365 mg de I2 e 40 mg de KI, e gerado ca. 2,2 mL de resíduo por determinação. Efeitos de matriz foram constatados e superados por calibração com compatibilização de matriz. Alternativamente, foi desenvolvimento um spot test utilizando imagens digitais, também baseado no consumo de I2 pelos compostos insaturados presentes na amostra, porém envolvendo a deposição de alíquotas de reagente em papel de filtro e a medida do I2 remanescente, na forma do complexo com amido. As medidas foram realizadas com a câmera de um celular e tratadas como reflectância. Resposta linear foi obtida entre 10-106 g I2/100 g de biodiesel, com coeficiente de variação (n = 10) e limite de detecção (99,7% nível de confiança) estimados em 5,0% e 8 g I2/100 g, respectivamente. Foram consumidos 40 ?L de amostra e 50 ?g de I2 e gerado 65 ?L de resíduo por determinação. A determinação do teor de éster baseou-se na formação do complexo violeta entre Fe(III) e hidroxamato, gerado pela reação entre os ésteres de alquila da amostra e hidroxilamina. Foi utilizado um sistema de análises de fluxo, explorando o processo lab-in-syringe, com etanol como solvente mediador para gerar uma única fase entre a amostra hidrofóbica e os reagentes hidrofílicos. Respostas lineares foram obtidas nos intervalos 4-99% (v/v) e 2-40% (v/v) para biodiesel e mistura biodiesel:diesel, respectivamente. Para as amostras de biodiesel, o coeficiente de variação, o limite de detecção e a frequência de amostragem foram estimados em 0,80% (n = 10), 0,36% e 15 h-1, respectivamente, enquanto para a mistura biodiesel:diesel foram 0,20%, 0,03% (v/v) e 12 h-1, respectivamente. Foram consumidos 40 ?L de amostra de biodiesel e 100 ?L da mistura biodiesel:diesel, 0,860 mg de hidroxilamina, 0,145 mg Fe e gerado ca. 3 mL de resíduo. Os resultados obtidos em todos os procedimentos foram concordantes com os obtidos em procedimentos de referência com 95% de confiança. Os procedimentos desenvolvidos são práticos e viáveis para análises on-line e at-line, além de consumirem pequenas quantidades de solventes orgânicos e reagentes e gerarem pequenos volumes de resíduos / The present dissertation is focused on the development of analytical procedures for the determination of iodine value in biodiesel and vegetable oils as well as of ester content in biodiesel and biodiesel:diesel blends. The procedure for the determination of iodine value was based on discoloration of a triiodide solution measured by spectrophotometry. For biodiesel and vegetable oil samples, linear responses were obtained from 10-106 g I2/100 g and 20-144 g I2/100 g, respectively. The coefficient of variation (n = 10) and limit of detection (99.7% confidence level) were 5.0% and 2.5 g I2/100 g, whereas for vegetable oils, the values were 3.0% and 7 g I2/100 g, respectively. About 1.2 mL of sample, 0.365 mg of I2 and 40 mg of KI were consumed per determination, with generation of ca. 2.2 mL of waste. Matrix effects were circumvented by matrix matching. Alternatively, a spot test using digital images was developed, also based on consumption of iodine by unsaturated compounds in the samples, but relying on deposition of reagent aliquots on a filter paper followed by measurement of remaining iodine, through its complex formed with starch. The measurements were performed with a cell phone camera and treated as reflectance. A linear response was obtained within 10 and 106 g I2/100 g of biodiesel. The coefficient of variation (n = 10) and limit of detection were (99.7% confidence level) estimated at 4.9% and 8 g I2/100 g, respectively. About 40 ?L of sample and 50 ?g of I2 were consumed per determination, with generation of ca. 65 ?L of waste per determination. Ester determination was based on reaction of alkyl esters from biodiesel and hydroxylamine, yielding hydroxamate, which was measured by spectrophotometry as an iron(III) complex. The flow-based procedure exploited the lab-in-syringe approach, by using ethanol as mediator solvent to generate a single phase between the hydrophobic sample and the hydrophilic reagents. Linear responses were obtained from 4 to 99% (v/v) and 2 to 40% (v/v) for biodiesel and biodiesel:diesel blends, respectively. For biodiesel samples the coefficient of variation (n = 10), detection limit (99.7% confidence level) and sampling rate were estimated at 0.80%, 0.36%, and 15 h-1, respectively, whereas for biodiesel:diesel blends, the corresponding values were 0.20%, 0.03% (v/v), and 12 h-1, respectively. About 40 µL of biodiesel or 100 µL biodiesel:diesel blends, 0.860 mg of hydroxylamine, and 0.145 mg Fe were consumed per determination, with generation of ca. 3 mL of waste. The results obtained by all the proposed procedures agreed with the reference ones at the 95% confidence level. The proposed procedures are practical and feasible for on-line or at-line analysis, by consuming only low amounts of organic solvents and reagents, and generating low waste volumes

A presente dissertação apresenta os resultados referentes ao desenvolvimento de procedimentos analíticos para a determinação de índice de iodo em biodiesel e óleo vegetal e do teor de éster em biodiesel e em misturas biodiesel:diesel. O primeiro procedimento para a determinação de índice de iodo foi baseado na descoloração de uma solução de I3- monitorada por espectrofotometria. Para amostras de biodiesel e óleo vegetal, foram obtidas respostas lineares nos intervalos de 10-106 g I2/100 g e 20-144 g I2/100 g, respectivamente. O coeficiente de variação (n = 10) e o limite de detecção (99,7% nível de confiança) foram estimados em 5,0% e 2,5 g I2/100 g para amostras de biodiesel, enquanto para amostras de óleos vegetais os valores foram 3,0% e 7 g I2/100 g, respectivamente. Foram consumidos ca. 1,2 mL de amostra, 0,365 mg de I2 e 40 mg de KI, e gerado ca. 2,2 mL de resíduo por determinação. Efeitos de matriz foram constatados e superados por calibração com compatibilização de matriz. Alternativamente, foi desenvolvimento um spot test utilizando imagens digitais, também baseado no consumo de I2 pelos compostos insaturados presentes na amostra, porém envolvendo a deposição de alíquotas de reagente em papel de filtro e a medida do I2 remanescente, na forma do complexo com amido. As medidas foram realizadas com a câmera de um celular e tratadas como reflectância. Resposta linear foi obtida entre 10-106 g I2/100 g de biodiesel, com coeficiente de variação (n = 10) e limite de detecção (99,7% nível de confiança) estimados em 5,0% e 8 g I2/100 g, respectivamente. Foram consumidos 40 ?L de amostra e 50 ?g de I2 e gerado 65 ?L de resíduo por determinação. A determinação do teor de éster baseou-se na formação do complexo violeta entre Fe(III) e hidroxamato, gerado pela reação entre os ésteres de alquila da amostra e hidroxilamina. Foi utilizado um sistema de análises de fluxo, explorando o processo lab-in-syringe, com etanol como solvente mediador para gerar uma única fase entre a amostra hidrofóbica e os reagentes hidrofílicos. Respostas lineares foram obtidas nos intervalos 4-99% (v/v) e 2-40% (v/v) para biodiesel e mistura biodiesel:diesel, respectivamente. Para as amostras de biodiesel, o coeficiente de variação, o limite de detecção e a frequência de amostragem foram estimados em 0,80% (n = 10), 0,36% e 15 h-1, respectivamente, enquanto para a mistura biodiesel:diesel foram 0,20%, 0,03% (v/v) e 12 h-1, respectivamente. Foram consumidos 40 ?L de amostra de biodiesel e 100 ?L da mistura biodiesel:diesel, 0,860 mg de hidroxilamina, 0,145 mg Fe e gerado ca. 3 mL de resíduo. Os resultados obtidos em todos os procedimentos foram concordantes com os obtidos em procedimentos de referência com 95% de confiança. Os procedimentos desenvolvidos são práticos e viáveis para análises on-line e at-line, além de consumirem pequenas quantidades de solventes orgânicos e reagentes e gerarem pequenos volumes de resíduos / The present dissertation is focused on the development of analytical procedures for the determination of iodine value in biodiesel and vegetable oils as well as of ester content in biodiesel and biodiesel:diesel blends. The procedure for the determination of iodine value was based on discoloration of a triiodide solution measured by spectrophotometry. For biodiesel and vegetable oil samples, linear responses were obtained from 10-106 g I2/100 g and 20-144 g I2/100 g, respectively. The coefficient of variation (n = 10) and limit of detection (99.7% confidence level) were 5.0% and 2.5 g I2/100 g, whereas for vegetable oils, the values were 3.0% and 7 g I2/100 g, respectively. About 1.2 mL of sample, 0.365 mg of I2 and 40 mg of KI were consumed per determination, with generation of ca. 2.2 mL of waste. Matrix effects were circumvented by matrix matching. Alternatively, a spot test using digital images was developed, also based on consumption of iodine by unsaturated compounds in the samples, but relying on deposition of reagent aliquots on a filter paper followed by measurement of remaining iodine, through its complex formed with starch. The measurements were performed with a cell phone camera and treated as reflectance. A linear response was obtained within 10 and 106 g I2/100 g of biodiesel. The coefficient of variation (n = 10) and limit of detection were (99.7% confidence level) estimated at 4.9% and 8 g I2/100 g, respectively. About 40 ?L of sample and 50 ?g of I2 were consumed per determination, with generation of ca. 65 ?L of waste per determination. Ester determination was based on reaction of alkyl esters from biodiesel and hydroxylamine, yielding hydroxamate, which was measured by spectrophotometry as an iron(III) complex. The flow-based procedure exploited the lab-in-syringe approach, by using ethanol as mediator solvent to generate a single phase between the hydrophobic sample and the hydrophilic reagents. Linear responses were obtained from 4 to 99% (v/v) and 2 to 40% (v/v) for biodiesel and biodiesel:diesel blends, respectively. For biodiesel samples the coefficient of variation (n = 10), detection limit (99.7% confidence level) and sampling rate were estimated at 0.80%, 0.36%, and 15 h-1, respectively, whereas for biodiesel:diesel blends, the corresponding values were 0.20%, 0.03% (v/v), and 12 h-1, respectively. About 40 µL of biodiesel or 100 µL biodiesel:diesel blends, 0.860 mg of hydroxylamine, and 0.145 mg Fe were consumed per determination, with generation of ca. 3 mL of waste. The results obtained by all the proposed procedures agreed with the reference ones at the 95% confidence level. The proposed procedures are practical and feasible for on-line or at-line analysis, by consuming only low amounts of organic solvents and reagents, and generating low waste volumes

Master of Science / Department of Animal Sciences and Industry / Michael Tokach / In 3 experiments, 4,720 pigs were used to determine the effects of: 1) dietary fat and feeding duration on growth performance and fat quality in finishing pigs; or 2) a novel protease or 3) increasing levels of Zn amino acid complex (ZnAA) or ZnO on finishing pig performance. Experiment 1 tested the effects of feeding tallow, soybean oil, or a blend of the two for various feeding durations (d 0 to 42, 42 to 84, or 0 to 84). Overall, pigs fed added fat for the entire 84 d had improved G:F compared to those fed a control diet. Additionally, pigs fed additional fat for the entire study had improved ADG and G:F as well as increased d 84 BW compared to pigs fed additional fat for 42 d. Increasing the feeding duration of soybean oil lowered monounsaturated fatty acids and increased polyunsaturated fatty acid concentrations while these values remained relatively unchanged by the addition of tallow. There were feeding period by fat source interactions for fatty acid composition and iodine value for belly and backfat, but not jowl fat, indicating a longer turnover rate for jowl fat compared to belly or backfat. In Exp. 2, adding a protease to a nutrient deficient diet increased ADFI and tended to increase ADG compared to pigs fed a negative control diet. There were no differences observed in ADG, ADFI, or G:F between pigs fed a positive control diet, formulated to 90% of the pigs SID lysine requirement, and those fed a negative control diet plus the protease, which would suggest the release values attributed to the enzyme were accurate. In Exp. 3, supplementing additional Zn from either ZnAA or ZnO at 25, 50, or 75 ppm in finishing diets for commercial finishing pigs was evaluated. Overall, no differences were observed in ADFI, but a Zn source by level interaction was observed for ADG and G:F, as pigs fed increasing ZnO were observed to have similar performance, while pigs fed added levels of 25 and 50 ppm Zn from ZnAA had decreased performance compared to those fed the highest level of ZnAA.

Orientador: Matthieu Tubino / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-16T16:51:27Z (GMT). No. of bitstreams: 1 Aricetti_JulianaAparecida_M.pdf: 3453712 bytes, checksum: 05441cfd4b0bc4b35a48f907bb26b81e (MD5) Previous issue date: 2010 / Resumo: No presente trabalho foram desenvolvidos métodos alternativos aos atualmente utilizados para a determinação do índice de acidez e do índice de iodo de biodiesel e de óleos e gorduras. Os métodos oficiais para a determinação do índice de acidez (ABNT NBR 14448 e AOCS 3d-63) são problemáticos devido ao uso de solventes tóxicos (álcool isopropílico e tolueno). Tais solventes ainda, apresentam problema metodológico, pois afetam, no método potenciométrico, o funcionamento do eletrodo de vidro devido à desidratação da membrana do mesmo. O método que utiliza indicador visual ácido-base apresenta baixa reprodutibilidade, baixa repetibilidade e baixa precisão, situação que se torna mais grave quando as amostras são coloridas, uma vez que a detecção do ponto final da titulação depende da percepção visual do analista. Com o intuito de contornar estes tipos de problemas, foram desenvolvidos dois métodos alternativos, sendo um potenciométrico (MPT - com base no método da ABNT NBR 14448) e outro titulométrico com uso de indicador visual ácido-base (MIV - com base no método AOCS Cd 3d-63). O MPT utiliza como solventes uma mistura constituída por água destilada e álcool etílico (50:50 v/v). É utilizado eletrodo de vidro preenchido com solução aquosa de KCl 3,0 mol L. Este método apresentou resultados de boa qualidade, redução considerável no custo e na toxicidade da análise, maior estabilidade do eletrodo de vidro quanto à desidratação da membrana e, portanto maior durabilidade. O método MIV segue o mesmo procedimento do método potenciométrico descrito e utiliza como indicador visual a fenolftaleína. Também neste caso, os resultados são de boa qualidade. Para ambos os métodos, o custo é cerca de 80% menor e a quantidade de resíduos gerados é cerca de 40% menor do que no caso dos métodos oficiais. Para a determinação do índice de iodo, foram desenvolvidos três métodos alternativos ao oficial para biodiesel e para óleos e gorduras (EN 14111 e AOCS Cd 1-25 ). Um deles é titulométrico com uso de indicador visual que utiliza como solvente álcool etílico e água destilada e gelada; e como reagente, solução etanólica de iodo. Todo o procedimento analítico pode ser realizado em cerca de 10 minutos. Os demais métodos são potenciométricos, sendo um baseado no método oficial (Wijs potenciométrico), onde a determinação do ponto final da titulação é realizada com uso de eletrodo de platina e outro no qual a determinação do ponto final da titulação também é realizada com eletrodo de platina mas em solução etanol-água. De modo geral, neste trabalho objetivou-se a substituição no uso de solventes tóxicos e do reagente de Wijs por outros mais amigáveis ambientalmente. Os métodos desenvolvidos apresentam menor custo (redução de cerca de 90%) e toxicidade muito mais baixa por conta dos solventes e reagentes utilizados. Os três métodos desenvolvidos apresentaram resultados coerentes com o método oficial. Estudou-se a possibilidade de correlacionar alguns dos parâmetros do biodiesel, determinados através dos métodos analíticos propostos, com o objetivo de reduzir o número necessário de análises segundo as exigências da ANP. Verificou-se, por exemplo, que é possível, com excelente correlação, determinar o índice de cetano através do índice de iodo / Abstract: In this work we developed alternative methods currently used for determining the acid value and iodine value of biodiesel and of oils and fats. The official methods for determining the acid value (ABNT NBR 14448 and AOCS 3d-63) are problematic due to the use of toxic solvents (isopropyl alcohol and toluene). These solvents also have methodological problem, because they affect, the potentiometric method, the operation of the glass electrode membrane due to dehydration of the same. The method that uses visual acid-base indicator has a low reproducibility, low repeatability and low accuracy, a situation that becomes more severe when the samples are colored, since the detection of end point depends on the visual perception of the analyst. In order to outline these types of problems, we developed two alternative methods, instead a potentiometric (MPT - based on the method of ABNT NBR 14448) and another titration with the use of visual indicator acid-base (MIV - based on the method AOCS Cd 3d-63). MPT uses as solvent a mixture consisting of distilled water and ethanol (50:50 v / v). It¿s used a glass electrode filled with aqueous solution of KCl 3.0 mol L. This method showed good results, considerable reduction in cost and of the toxicity analysis, greater stability of the glass electrode as the dehydration of the membrane are more durable. The MIV method follows the same procedure of the potentiometric method described and used as visual indicator phenolphthalein. Here too, the results are of good quality. For both methods, the cost is about 80% lower and the amount of waste produced is about 40% lower than in the case of official methods. For the determination of iodine value, we were developed three alternatives to the official for biodiesel and for oils and fats (EN 14 111 and AOCS Cd 1-25). One is titration with the use of visual indicator that uses as solvent ethyl alcohol and distilled water and ice, and as reagent solution of iodine in ethanol. The whole analytical procedure can be performed in about 10 minutes. The other methods are potentiometric, on based on the official method (potenciometric Wijs), where the determinaton of the end point is preformed using a platinum electrode and another in which the determination of the end point is also made with platinum electrode but in ethanol-water solution. Generaly, this study aimed to replace the use of toxic solvents and reagent Wijs for other more environmentally friendly. The methods developed have lower cost (reduction of about 90%) and much lower toxicity due to the solvents and reagents used. The three developed methods showed good agreement with the results of official method. We studied the possibility to correlate some of the parameters of the biodiesel, as determined by the methods proposed, aiming to reduce the required number of tests as required by ANP. There was, for example, which is possible, with excellent correlation, to determine the cetane number by iodine / Mestrado / Quimica Analitica / Mestre em Química

Made available in DSpace on 2016-08-17T14:52:38Z (GMT). No. of bitstreams: 1 DISSERTACAO_RAQUEL MACHADO DE SOUSA.pdf: 3658389 bytes, checksum: 42d5adba41b1c3d2c90530fe77f43b2c (MD5) Previous issue date: 2015-02-26 / To ensure efficient combustion and emissions quality, as well as safety in the transport and handling of biodiesel, the National Agency of Petroleum, Natural Gas and Biofuels (ANP) establishing, through Resolution No. 14 of 2012, quality standards and specifications for this biofuel, and for that many official or alternative methods may be used. In literature, it is possible to identify an increasing use of linear methods and non - linear in the recognition and classification standards applied to the monitoring of biodiesel quality. In this context, the Artificial Neural Networks (ANN) have shown to be quite viable, as a tool non - linear, in predicting biofuel properties. The present work proposes to assess the prediction of biodiesel quality properties using supervised training algorithms of ANNs. In order to contribute to a study to provide a network structure with a training algorithm that can perform better with good results in the prediction. Through the prediction of the properties of the biodiesel from the composition of the esters of the raw material, it is possible to assess the feasibility of using such raw materials for the synthesis of a quality biodiesel. In this work we obtained a better ANN architecture for iodine value prediction and viscosity. The results of the simulations showed that the ANNs are a technology that can be used to predict these properties, like other related composition of fatty acid esters. / Para assegurar uma combustão eficiente e qualidade nas emissões, bem como a segurança no transporte e manuseio do biodiesel, a Agência Nacional do Petróleo, Gás Natural e Biocombustíveis (ANP) institui, por meio da Resolução nº 14 de 2012, parâmetros de qualidade e especificações para esse biocombustível, e para isso diversos métodos oficiais ou alternativos podem ser utilizados. Na literatura, é possível identificar uma crescente utilização de métodos lineares e não- lineares no reconhecimento e classificação de padrões aplicados ao monitoramento da qualidade de biodiesel. Nesse contexto, as Redes Neurais Artificiais (RNAs) vêm se mostrando bastante viáveis, como ferramenta não lineares, na predição de propriedades de biocombustíveis. O presente trabalho propõe avaliar a predição de propriedades de qualidade de biodiesel utilizando algoritmos de treinamento supervisionado de RNAs. De modo a contribuir com um estudo para se obter uma estrutura de rede com um algoritmo de treinamento que consiga bons resultados com melhor desempenho na predição. Por meio da predição das propriedades do biodiesel a partir da composição dos ésteres da matéria-prima, será possível avaliar a viabilidade da utilização de tal matéria-prima para a síntese de um biodiesel de qualidade. No presente trabalho obteve-se uma melhor arquitetura de RNA para predição de índice de iodo e viscosidade. Os resultados obtidos das simulações mostraram que as RNAs são uma tecnologia que pode ser utlizada para predizer essas propriedades, como outras relacionadas a composição de ésteres de ácidos graxos.