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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

GVO-Spuren und Gentechnikrecht : die rechtliche Beurteilung und Handhabung von ungewollten Spuren gentechnisch veränderter Organismen in konventionell und ökologisch erzeugten Produkten /

Ostertag, Alice. January 2006 (has links)
Thesis (doctoral)--Universität, Freiburg (Breisgau), 2005. / Includes bibliographical references (p. 453-474).
62

Detection and quantification of spice adulteration by near infrared hyperspectral imaging

September, Danwille Jacqwin Franco 03 1900 (has links)
Thesis (MSc Food Sc)--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: Near infrared hyperspectral imaging (NIR HSI) in conjunction with multivariate image analysis was evaluated for the detection of millet and buckwheat flour in ground black pepper. Additionally, midinfrared (MIR) spectroscopy was used for the quantification of millet and buckwheat flour in ground black pepper. These techniques were applied as they allow non-destructive, invasive and rapid analysis. Black pepper and adulterant (either millet or buckwheat flour) mixtures were made in 5% (w/w) increments spanning the range 0-100% (w/w). The mixtures were transferred to eppendorf tube holders and imaged with a sisuChema short wave infrared (SWIR) pushbroom imaging system across the spectral range of 1000–2498 nm. Principal component analysis (PCA) was applied to pseudo-absorbance images for the removal of unwanted data (e.g. background, shading effects and bad pixels). PCA was subsequently applied to the ‘cleaned’ data. An adulterant concentration related gradient was observed in principal component one (PC1) and a difference between black pepper adulterated with buckwheat and millet was noted in PC4. Four absorption peaks (1461, 2241, 2303 and 2347 nm) were identified in the loading line plot of PC1 that are associated with protein and oil. The loading line plot of PC4 revealed absorption peaks at 1955, 1999, 2136 and 2303 nm, that are related to protein and oil. Partial least squares discriminant analysis (PLS-DA) was applied to NIR HSI images for discrimination between black pepper adulterated with varying amounts of adulterant (millet or buckwheat). The model created with millet adulterated black pepper samples had a classification accuracy of 77%; a classification accuracy of 70% was obtained for the buckwheat adulterated black pepper samples. An average spectrum was calculated for each sample in the NIR HSI images and the resultant spectra were used for the quantification of adulterant (millet or buckwheat) in ground black pepper. All samples were also analysed using an attenuated total reflectance (ATR) Fourier transform (FT) – infrared (IR) instrument and MIR spectra were collected between 576 and 3999 cm-1. PLS regression was employed. NIR based predictions (r2 = 0.99, RMSEP = 3.02% (w/w), PLS factor = 4) were more accurate than MIR based predictions (r2 = 0.56, RMSEP = 19.94% (w/w), PLS factors = 7). Preprocessed NIR spectra revealed adulterant specific absorption bands (1743, 2112 and 2167 nm) whereas preprocessed MIR spectra revealed a buckwheat specific signal at 1574 cm-1. NIR HSI has great promise for both the qualitative and quantitative analysis of powdered food products. Our study signals the beginning of incorporating hyperspectral imaging in the analysis of powdered food substances and results can be improved with advances in instrumental development and better sample preparation. / AFRIKAANSE OPSOMMING: Die gebruik van naby infrarooi hiperspektrale beelding (NIR HB) tesame met veelvoudige beeldanalise is ondersoek vir die opsporing van stysel-verwante produkte (giers en bokwiet) in gemaalde swart pepper. Middel-infrarooi (MIR) spektroskopie is addisioneel gebruik vir die kwantifisering van hierdie stysel-verwante produkte in swart pepper. Albei hierdie tegnieke is toegepas aangesien dit deurdringend van aard is en dit bied nie-destruktiewe sowel as spoedige analise. Swart pepper en vervalsingsmiddel (giers of bokwiet) mengsels is uitgevoer in 5% (m/m) inkremente tussen 0 en 100% (m/m). Eppendorfbuishouers is met die mengsels gevul en hiperspektrale beelde is verkry deur die gebruik van ‘n sisuChema SWIR (kortgolf infrarooi) kamera met ‘n spektrale reikwydte van 1000–2498 nm. Hoofkomponent-analise (HK) is toegepas op pseudo-absorbansie beelde vir die verwydering van ongewenste data (bv. agtergrond, skadu en dooie piksels). Hoofkomponent-analise is vervolgens toegepas op die ‘skoon’ data. Hoofkomponent (HK) een (HK1) het die aanwesigheid van ‘n vervalsingsmiddel konsentrasie verwante gradient getoon terwyl HK4 ‘n verskil getoon het tussen swart pepper vervals met giers en bokwiet. Vier absorpsiepieke (1461, 2241, 2303 en 2347 nm) was geïdentifiseer binne die HK lading stip van HK1 wat met proteïen en olie geassosieer kon word. Die HK lading stip van HK4 het absorpsipieke by 1955, 1999, 2136 en 2303 nm aangedui wat verband hou met proteïen en olie. Parsiële kleinste waarde diskriminant-analise (PKW-DA) is toegepas op die hiperspektrale beelde vir die moontlike onderskeiding tussen swart pepper vervals met verskeie hoeveelhede vervalsingsmiddel (giers of bokwiet). ‘n Klassifikasie koers van 77% is verkry vir die model ontwikkel met giers vervalsde swart pepper terwyl die model ontwikkel met bokwiet vervalsde swarte pepper ‘n klassifikasie koers van 70% bereik het. ‘n Gemiddelde spektrum is bereken vir elke monster in die hiperspektrale beelde en die resulterende spektra is gebruik vir die kwantifisering van vervalsingsmiddels (giers of bokwiet) in gemaalde swart pepper. ‘n ATR FT-IR instrument met spektrale reikwydte van 576-3999 cm-1 is additioneel gebruik vir die analise van alle monsters. Parsiële kleinste waarde regressie is gebruik vir kwantifikasie doeleindes. NIR gebasseerde voorspellings (r2 = 0.99, RMSEP = 3.02% (m/m), PLS faktore = 4) was meer akkuraat as die MIR gebasseerde voorspellings (r2 = 0.56, RMSEP = 19.94% (m/m), PLS faktore = 7). Vooraf behandelde NIR spektra het vervalsingsmiddel verwante absorpsiepieke (1743, 2112 en 2167 nm) aangetoon terwyl vooraf behandelde MIR spektra ‘n bokwiet verwante absorpsiepiek by 1574 cm-1 aangedui het. NIR HB toon goeie potensiaal vir beide kwalitatiewe en kwantitatiewe analise van gepoeierde voedsel produkte. Ons studie kan gesien word as die begin van die inkorporasie van hiperspektrale beelding in die analise van gepoeierde voedsel material en verbeterde resulte kan verkry word deur die vordering in instrumentasie ontwikkeling en verbeterde monstervoorbereiding.
63

Análise isotópica da variabilidade natural do carbono-13 e análise energética em suco, néctar e refrigerante de maçã (malus domestica, borkh) /

Figueira, Ricardo, 1980- January 2008 (has links)
Orientador: Waldemar Gastoni Venturini Filho / co- orientador : Carlos Ducatti / Banca: Léa Silvia Mara Sant'ana / Banca: Muris Sleiman / Banca: José Albertino Bendassolli / Resumo: O objetivo deste trabalho foi desenvolver o método de análise isotópica para a quantificação de fonte C3 em suco, néctar e refrigerante de maçã. Essas bebidas foram produzidas em laboratório, conforme a legislação brasileira. Também foram produzidos sucos adulterados (quantidade de açúcar de cana acima do permitido), néctares e refrigerantes adulterados (quantidade insuficiente de suco). Nessas bebidas, foram feitas análises de ºBrix, pH, acidez titulável, ratio, análise energética e análise isotópica. Para as análises isotópicas foi mensurado o enriquecimento isotópico relativo das bebidas de maçã bem como de suas frações (polpa lavada com água, polpa lavada com acetona e açúcar purificado extraído das bebidas de maçã). Com estes resultados foi estimada a quantidade de fonte C3 pela equação da diluição isotópica. Para determinar a legalidade das bebidas comerciais de maçã foi necessário a criação do limite de legalidade para separar as bebidas que estão de acordo com a legislação brasileira. Os valores da quantificação de fonte C3 acima do limite de legalidade foram considerados legais. Caso estes valores estejam abaixo deste limite, estes produtos foram considerados adulterados conforme as normas brasileiras. A metodologia desenvolvida para sucos, néctares e refrigerantes de maçã comerciais provou ser eficiente para separar os produtos que estão de acordo com a legislação. Esta metodologia também pode ser aplicada para verificar a legalidade em outras bebidas de frutas comerciais. / The goal of this work was to develop an isotopic analysis method to the C3 source quantification in juice, nectar and apple soft drink. In laboratory, juice, nectar and apple soft drink were produced according to Brazilian legislation. Also adulterated juices (cane sugar quantity up admitted), nectar and soft drink adulterated (insufficient juice quantity) were produced. In these beverages, analysis of ºBrix, pH, titratable acidity, ratio, energetic and isotopic analysis were made. For the isotopic analysis, the isotopic enrichment of apple beverages and fractions of this beverages (pulpy washed with water, pulpy washed with acetone and sugar purified extracted of apple beverages) were measured. With these results, the C3 quantification was estimated by the equation of isotopic dilution. For determine the legality of apple commercial beverages, the creation of legality limit for separate the lawful beverages was necessary. The values of C3 quantification above the legality limit were considerate lawful. If below of the legality limit were considerates unlawful according to the Brazilian rules. The methodology developed for commercial juices, nectars and apple soft drinks was efficient to separate the lawful beverages. This methodology can be applied for verify the legality in others commercial fruit beverages. / Doutor
64

Les infractions consommées par le mensonge / The infractions proved (done) through lie

Comert, Alev 14 December 2015 (has links)
Le mensonge est un fait omniprésent dans notre vie. La religion et les règles morales condamne tout mensonge parce qu’il est le signe de trahison des valeurs morales universelles communes à toutes les sociétés. Tous les jugements et les droits doivent nécessairement reposer sur la vérité. Les règles juridiques, inspiré de règles religieuses et morales, répriment également le mensonge. Toutefois, en application des principes régissant la matière, le droit pénal ne réprime que les mensonges concrètement nuisibles à la société et aux individus. La sanction du mensonge nécessite que l’usage du mensonge permette de parvenir à une fin prohibée par la loi pénale. L’intervention du législateur est justifiée et légitimée par des impératifs d’ordre public imposant la protection des valeurs sociales nécessaires au fonctionnement de la société. La recherche entreprise porte sur les infractions consommées par le mensonge en droit pénal. Le droit pénal conçoit le mensonge comme une déviation par rapport à la vérité réalisée sous des multiples formes, sans apporter une définition précise. La matière pénale ne s’intéresse pas à une inexactitude en tant que telle, mais au mensonge, qui par définition, ne peut être qu’intentionnel, fait de mauvaise foi dans le but de tromper. Cette étude a pour but de d’identifier les critères retenus lors de la répression du mensonge dans toutes les infractions consommées par une altération frauduleuse de la vérité. A la lecture du Code pénal, on peut constater que de nombreuses infractions sont construites sur le mensonge. Conformément aux principes régissant le droit pénal, la répression du mensonge doit se faire qu'en fonction de critères objectifs et déterminés. Les réformes et les évolutions substantielles génèrent des incertitudes sur les frontières traditionnellement admises du mensonge punissable et génèrent une problématique renouvelée. Les composantes des infractions sont affectées par des transformations majeures et rendent la ligne de démarcation de la répression mouvante. La jurisprudence confirme cette tendance et témoignent de la souplesse observée lors de la caractérisation du mensonge. / Lying is a fact of life. Both religion and morality condemn lying as a sign of treason against the universal moral rules common to all societies. All judgements and all laws must rely on truth. Legal rules, inspired by religious and moral rules, repress the use of lies. Applying the principles of this subject, however, criminal law only represses lies that specifically harm society or individuals. Lies are only punished if their use facilitates actions prohibited by penal law. The intervention of the legislator is justified and legitimate to ensure public order and protect the social values essential for the functioning of society. The following research aims to show the (proven) violations committed by the act of lying. Penal law considers lies a deviation from the truth that manifests itself in a number of ways and does not have a precise definition. In criminal matters, inaccuracy is not the most crucial aspect –lies are by definition necessarily instances of intentional deception. This study aims to identify the criteria applied for the punishment of lying in cases of violations of the law that resort to an alteration of the truth with fraudulent intent. Reading the criminal code, we see that a large number of violations are based on lies. According to the penal law principles, the punishment of lying must be based on specific and objective criteria only. Reforms and substantial transformations throw uncertainties upon the traditionally accepted demarcations of punishable lies, which perpetuates the problem. The components of these violations are affected by major transformations, which leads to unclear determination of punishment. Juriceprudence confirms this tendency and shows certain flexibility during the characterisation of what constitutes a lie.
65

Avaliação da qualidade físico-química e microbiológica do mel das abelhas africanizadas (Apis melliferaL.) da região Leste/RN Brasil. / Evaluation of the physical-chemical and microbiological quality of the Africanized bee s honey (Apis mellifera L.) from the East Region, RN in Brazil

Medeiros, Altevir Paula de 31 August 2011 (has links)
Made available in DSpace on 2016-08-15T20:31:00Z (GMT). No. of bitstreams: 1 AltevirPM_DISSERT.pdf: 757570 bytes, checksum: a681ad77207595274ca2835fa19c8e0e (MD5) Previous issue date: 2011-08-31 / It has been verified the honey produced by Apis mellifera L. in the East Potiguar Mesoregion, RN, Brazil, to identify if they satisfy the specifications determined by the legislations. 90 samples have been analyzed determining the physical-chemical parameters, qualitative tests, microbiological and with some adulterations done (addition of commercial sugar and corn glucose) to check the detection limits of Lund and Lugol s tests. The samples were collected for a honey exporting company from RN and sent to UFERSA, in aliquots of 500ml and analyzed 48 hours after each collection. They were collected from January to February in 2009. The following results were obtained: moisture (15,23%±0,56%), water activity (0,61±0,02%), solids (0,04±0,02%), ashes (0,19±0,09%), acidity (31,55 meq/kg±6,67), sugar (76,61%±6,22), sucrose (4,72%±0,87), HMF (14,16 mg/kg±8,86), Lund (2,96+0,99%) and negative diastase activity. The values of moisture, HMF, sugar, free acidity, insoluble solids and ashes have been in accordance with the regulations of BRASIL (2000), Codex (2001) and MERCOSUL (CMG 89/99). The microbiological parameters analyzed were: coliform presence at 35°C and 45°C, Salmonella sp, mold and yeast quantification from the 90 samples of the collected honey. 60 samples presented a mold and yeast counting higher than 102 UFC/g above the permitted amount by MERCOSUL s legislation with the limit of 1X102 UFC/g or 100 UFC per gram. The honey samples analyzed had values higher than >1.100 NMP/g to coliforms at 35°C and 45°C and seven samples with growth between 15 and 3,6 NMP/g-1 which are considered so high, based on the legislation of MERCOSUL the maximum limit of <3 NMP/g. Two samples presented Salmonella sp that suggests the necessity of implementation of good practices in all the levels of the productive chain, especially in the apiary and the necessity of knowing the microbiota of honey in the regions of Brazil; / Foram verificados se méis produzidos por Apis melliferaL., na Mesorregião Leste Potiguar - RN Brasil, cumprem as especificações determinadas pelas legislações. Foram analisadas 90 amostras determinando os parâmetros físico-químicos, testes qualitativos, microbiológicos e realizaram-se adulterações (adição de açúcar comercial e glucose de milho) para testar os limites de detecção dos testes de Lund e Lugol. As amostras foram coletadas por uma empresa exportadora de mel do Estado do RN e enviadas para análise em alíquotas de 500 ml e analisadas 48 horas após cada coleta. Foram coletas de janeiro a dezembro de 2009,obtendo os seguintes resultados: umidade (15,23%±0,56%), atividade de água (0,61±0,02%), sólidos (0,04±0,02%), cinzas (0,19±0,09%), acidez (31,55 meq/kg±6,67), açúcares (76,61%±6,22), sacarose (4,72%±0,87), HMF (14,16 mg/kg±8,86), Lund (2,96+0,99%) e atividade diastásica negativa. Os valores de umidade, HMF, açúcares, acidez livre, sólidos insolúveis e cinzas estiveram de acordo com os regulamentos do BRASIL (2000), Codex (2001) e o MERCOSUL (GMC 89/99). Os parâmetros microbiológicos analisados foram: presença de coliformes a 35ºC e 45ºC, Salmonella sp, quantificação de bolores e leveduras das 90 amostras de mel coletadas. 60 amostras apresentaram contagem de bolores e leveduras maiores que 102 UFC/g, acima do permitido pela legislação do MERCOSUL com limite de 1X102 UFC/g ou 100 UFC por grama. Amostras de mel analisadas tinham valores maiores que >1.100 NMP/g para coliformes a 35ºC e 45ºC e sete amostras com crescimento entre 15 e 3,6 NMP/g-1 sendo estes valores bem elevados tendo como base a legislação do MERCOSUL o limite Maximo de <3 NMP/g. Duas amostras apresentaram Salmonella sp, o que sugere a necessidade de implementação das boas práticas em todos os níveis da cadeia produtiva, em especial no apiário e da necessidade de se conhecer a microbiota dos méis das regiões do Brasil);
66

A altera??o do tipo penal de adultera??o de combust?veis: reflexo da constitucionaliza??o do direito penal no mercado de combust?veis

Pinheiro Neto, Luiz Felipe 19 March 2014 (has links)
Made available in DSpace on 2014-12-17T14:27:29Z (GMT). No. of bitstreams: 1 LuizFPN_DISSERT.pdf: 1155478 bytes, checksum: 9e8987b9d6b2c6260ed4b50e8325c276 (MD5) Previous issue date: 2014-03-19 / The neoconstitutionalism led to a process of ethical revaluation of the normative systems and the process of constitutionalization of the many fields of law. This study examines the consequences of this process in criminal law, so important a Law field for the protection of the most valuable assets by the society, including the fundamental guarantees, thus emphasizing the necessity of protection of the collective and individual rights, which are guided by the observance of the defendants individual rights in the course of criminal proceedings and the search for the best efficiency of penal protection, according to the corollaries of defense against the state (prohibition of the excess or ?bermassverbot) and the provision of rights by the state (prohibition of insufficient protection or Untermassverbot). The offense of fuel adulteration is taken as an object of study, since it is a vital market to a nation dependent of people and good s movement for their living, driven by fossil and biofuels. Such a crime affects essential legal interests to the development of society, interests such as the environment, consumer relations and economic order, particularly the principle of free competition. This paper seeks to analyze the need of a greater efficiency of this particular criminal protection, once concluded the conduct harm and social fear as a consequence by it as growing, and therefore having its former crime type, engraved in Article 1 of Law No. 8.176/1991, rewritten in compliance with the criminal law s principle of legality. Thus, the reformation proposals and legislative creation involving this crime were observed, with emphasis on the bill No. 2498/2003, which keeps it as blank heterogeneous criminal norm, kind of penal normative whose constitutionality is raised, including the forethought of criminal responsibility in the perpetrating of the offense as culpable and subsequently increasing the applicable minimum penalty, as well as the inclusion of new activities in the typical nucleus / O neoconstitucionalismo levou a um processo de revaloriza??o ?tica dos sistemas normativos e o processo de Constitucionaliza??o dos v?rios ramos do Direito. O presente estudo analisa as conseq??ncias deste processo no Direito Penal, ramo ?ltimo de prote??o dos bens mais valorados pela sociedade, incluindo as garantias fundamentais, destacando a necessidade de prote??o da coletividade e do indiv?duo, o que passa pela observ?ncia das garantias individuais dos acusados no curso do processo penal e pela busca de melhor efici?ncia da prote??o penal, conforme os corol?rios da defesa contra o Estado (proibi??o de excesso ou ?bermassverbot) e a presta??o pelo Estado (proibi??o de infraprote??o ou Untermassverbot). Toma-se por objeto de estudo o delito de adultera??o de combust?veis, os quais comp?em mercado vital para uma na??o dependente do deslocamento de pessoas e mercadorias para sua viv?ncia, impulsionada por combust?veis f?sseis e biocombust?veis. Tal crime atinge bens jur?dicos vitais ao desenvolvimento da sociedade, como o meio ambiente, as rela??es de consumo e a ordem econ?mica, destacando-se o princ?pio da livre concorr?ncia. Busca o presente trabalho analisar a necessidade da maior efici?ncia desta espec?fica prote??o penal, verificada a danosidade da conduta e o temor social por ela despertado, o que passa por uma reformula??o da reda??o do tipo penal insculpido no artigo 1? da Lei n? 8.176/1991, em observ?ncia ao princ?pio da legalidade no Direito Penal. Observam-se assim as propostas de reforma e cria??o legislativa envolvendo este crime, com destaque para o Projeto de Lei n? 2498/2003, que o mant?m como norma penal em branco heterog?nea, esp?cie normativa cuja constitucionalidade ? abordada, e incluindo a previs?o de responsabiliza??o criminal no cometimento do delito na modalidade culposa e majorando a pena m?nima aplic?vel, al?m da inclus?o de novas atividades no n?cleo t?pico
67

The impact of the logistical process on food safety and quality for maize export in South Africa

Swart, Jacobus Johannes January 2012 (has links)
To be submitted in fulfilment of the requirements for the degree MASTER OF TECHNOLOGIAE: In Quality In the Faculty of Engineering AT THE CAPE PENINSULA UNIVERSITY OF TECHNOLOGY, 2012 / Over the last decades, due to the lack of safety concern and inadequate quality management in logistical process, it caused unsafe and poor quality of maize products. Thus, this study looks into the key factors that affect maize exports from South Africa in order to improve the logistical processes and reduce the risks involved in the process. The main risks associated with poor traceability and logistical chain management of maize export, as well as issues pertaining to non-conformance to the different food safety standards were explored. Data were collected a group of food business operators (FBO) (n1=127) and food business inspectors (n2=20) through a number of interviews and a self-administered questionnaire. Data were then analysed by using the SPSS-V19 programme to generate descriptive statistical results to determine the specific needs and gaps within the current system as well as providing recommendations on the specific food safety changes pertaining to the maize export industry. The results showed that there is a lack of understanding among role-players regarding FBO legislation. In the comparison of many large companies, there is only a few small role-players adhere to the legislation pertaining to food safety and traceability. This has impacted on the quality of maize products negatively. This strongly suggested that all role-players that handle maize for export must be registered for FBO codes with Department of Agriculture, Forestry and Fisheries. The study also recommended that the Perishable Products Export Control Board (PPECB) should inspect and confirm the legitimacy of the FBO codes that appears on the maize export documentation. Keywords: Quality, food safety, food business operator, maize export, logistical processes, and traceability.
68

Desenvolvimento de método analítico para determinação dos principais adulterantes da cocaína em urina humana

Sena, Laís Cristina Santana 19 February 2016 (has links)
Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Cocaine is a stimulant that features a strong ability to cause dependence. Often adulterants are added to this drug in order to mimic its action or minimize its adverse effects. When there are other pharmacologically active components in the drug composition, severe problems can occur to users’ health, such as intoxication symptoms. Thus, the aim of this study was to develop a method for the determination of the main adulterants of cocaine (caffeine, levamisole, lidocaine, phenacetin, diltiazem, and hydroxyzine) in human urine. The high-performance liquid chromatography with a photodiode array detector and the dispersive liquid-liquid microextraction based on solidification of floating organic drop were used as analysis technique and as sample preparation technique, respectively. The reversed-phase chromatographic separation was obtained with a C18 column (250 x 4.6 mm; 5 μm; 80 Å) in gradient elution mode using acetonitrile-trifluoroacetic acid 0.026% (v/v) at 1 mL min-1 as mobile phase, at 25°C, and detection at 235 nm. The analysis time was 25 min. Under optimum conditions, human urine samples were alkalized with 0.5 mol.L-1 sodium phosphate buffer (pH 10) and added sodium chloride (20% m/v). Acetonitrile (150 μL) and 1-dodecanol (30 μL) were used as dispersive and extraction solvent, respectively. The method presented linear range of 312.5 – 3125 ng.mL−1 for caffeine and levamisole and 187.5 – 1875 ng.mL−1 for lidocaine, phenacetin, diltiazem, and hydroxyzine, with limit of quantification of 187.5 ng.mL-1 to lidocaine, phenacetin, diltiazem, and hydroxyzine and 312.5 ng.mL-1 for caffeine and levamisole. Recovery mean values were between 6.0 and 42.6%. The method showed good precision and accuracy, with within- and between-run relative standard deviation and relative error less than 15%. The samples were stable after freeze-thaw cycle and short-term room temperature stability tests. Additionally, this method was applied in samples of urine of five cocaine users and at least one adulterant was identified in all samples. It is expected that this method will contribute to the precision in the diagnosis of cocaine adulterants’ intoxication and to the proper planning of therapeutic measures. / A cocaína é uma droga estimulante que apresenta capacidade de causar dependência. Frequentemente são adicionados a esta droga adulterantes com o intuito de mimetizar sua ação ou minimizar seus efeitos adversos. Quando há nessa droga outros componentes farmacologicamente ativos, agravos à saúde dos usuários podem ocorrer, como quadros de intoxicação. Assim, o objetivo deste trabalho foi desenvolver um método de determinação dos principais adulterantes da cocaína (cafeína, levamisol, lidocaína, fenacetina, diltiazem e hidroxizina) em urina humana. A cromatografia líquida de alta eficiência com detector de arranjo de fotodiodos foi utilizada como técnica de análise e a microextração líquido-líquido dispersiva com solidificação da gota orgânica flutuante, como técnica de preparo das amostras. A separação cromatográfica dos analitos em fase reversa foi obtida em uma coluna C18 (250 x 4,6 mm; 5 μm; 80 Å) em modo gradiente e usando acetonitrila-ácido trifluoroacético 0,026% (v/v) a 1 mL.min-1 como fase móvel (25°C e detecção a 235 nm). O tempo de análise foi de 25 min. Para o preparo da amostra, a urina foi alcalinizada com tampão fosfato de sódio 0,5 mol.L-1 (pH 10) e adicionada de cloreto de sódio (20% m/v). Acetonitrila (150 μL) e 1-dodecanol (30 μL) foram utilizados como solvente dispersor e extrator, respectivamente. O método apresentou intervalos lineares de concentração de 312,5 – 3125 ng.mL−1 para cafeína e levamisol e de 187,5 – 1875 ng.mL−1 para lidocaína, fenacetina, diltiazem e hidroxizina, com limite de quantificação de 187,5 ng.mL-1 para lidocaína, fenacetina, diltiazem e hidroxizina e 312,5 ng.mL-1 para cafeína e levamisol. Os valores médios de recuperação variaram de 6,0 a 42,6%. O método mostrou boa precisão e exatidão intra e intercorrida com coeficientes de variação e erros relativos menores que 15%. As amostras apresentaram-se estáveis após ciclos de congelamento-descongelamento e após serem mantidas por 24h em temperatura ambiente. Ainda, o método foi aplicado em cinco amostras de urina de usuários de cocaína e pelo menos um adulterante foi identificado em todas as amostras. Espera-se que este método possa contribuir para a precisão no diagnóstico das intoxicações por adulterantes da cocaína e para o adequado planejamento das medidas terapêuticas.
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The use of Generalized Two-Dimensional FT-Raman Correlation Spectroscopy method to monitor the quality of automotive gasoline. / Qualidade de gasolinas automotivas atravÃs de Espectroscopia Vibracional FT-Raman, combinada com correlaÃÃo 2D generalizada.

Kellen Cristina Vilhena Lima 16 December 2005 (has links)
Relata a utilizaÃÃo da espectroscopia FT-Raman combinada com CorrelaÃÃo 2D Generalizada como mÃtodo alternativo para a realizaÃÃo do controle de qualidade de Gasolinas automotivas diretamente nos postos de combustÃvel. Apresenta os procedimentos para identificar a adulteraÃÃo da Gasolina automotiva pela adiÃÃo irregular de Etanol, Metanol e compostos aromÃticos e parafÃnicos, atravÃs da anÃlise dos espectros Raman obtidos para os diferentes adulterantes separadamente, misturados à Gasolina A e misturados à Gasolina A e ao Etanol. Descreve os procedimentos de prÃ-tratamento sobre os espectros Raman, a aplicaÃÃo do mÃtodo de CorrelaÃÃo 2D Generalizada aos sistemas estudados e a determinaÃÃo das curvas de calibraÃÃo que relacionam as intensidades integradas das bandas Raman com o teor de adulterante na Gasolina. Apresenta a praticidade de aplicaÃÃo do mÃtodo, que possibilita verificar a adulteraÃÃo da Gasolina automotiva atravÃs da comparaÃÃo entre o espectro Raman da amostra cuja conformidade se deseja verificar com o espectro da amostra padrÃo. Enfatiza a flexibilidade e a viabilidade de se ter um padrÃo especÃfico para cada distribuidora, ou atà mesmo para cada nova produÃÃo de Gasolina da refinaria. / It is reported the use of Generalized Two-Dimensional FT-Raman Correlation Spectroscopy (2DCOS-FT-Raman) method to monitor the quality of automotive gasoline in the gas stations. It is presented a procedure to identify the adulteration of automotive gasoline by the illicit addition of ethanol, methanol, aromatic and paraphinic compounds through the analysis of the Raman spectra obtained for different compositions of adulterants added to gasoline âAâ type and to gasoline âAâ type plus ethanol samples. It is discussed the data preconditioning step, the application of 2DCOS method, and the calibration curves that correlates the integrated intensities of the Raman bands of a given adulterant with its percentage in a given gasoline sample. It shown the protocol for using the 2DCOS-FT-Raman method to verify the adulteration in a given gasoline sample compared with a specific standard. This work emphasizes the flexibility and viability of using this method to have a specific standard for each gasoline distribution firm and also for each new gasoline derived from the refinery.
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Desenvolvimento de procedimento analítico limpo e com alta sensibilidade para a determinação de melamina em leite / Development of a green and highly sensitive analytical procedure for the determination of melamine in milk

Carina de Fátima Nascimento 13 March 2014 (has links)
A melamina é um composto tóxico ilegalmente empregado para adulterar o teor de proteínas em leite. A ingestão de pequenas quantidades de melamina pode causar complicações renais e até mesmo a morte de animais e humanos. Os procedimentos usuais para a determinação de proteínas são baseados na quantificação de nitrogênio total e não permitem detectar a adulteração. Neste trabalho, um procedimento rápido e limpo foi desenvolvido para a determinação de melamina como adulterante em leite. Triton X-114 foi utilizado para o clean-up da amostra e como fluoróforo. A determinação da melamina foi baseada na supressão da fluorescência do surfactante na fase pobre após a extração em ponto nuvem. Resposta linear foi observada entre 1,0 e 6,0 mg L- 1 de melamina, descrita pela equação de Stern-Volmer I°/I = 0,999 + 0,0165 CMEL (r = 0,999). O limite de detecção foi estimado em 0,8 mg L- 1 (nível de confiança de 95 %), o que permite a detecção de 320 \'mü\'g de melamina em 100 g de leite. Coeficientes de variação (n = 8) foram estimados em 0,4 e 1,4 % na ausência e na presença do analito, respectivamente. Recuperações entre 95 e 102% e os coeficientes angulares das curvas de calibração obtidas na presença e ausência de leite indicaram a ausência de efeitos da matriz. Os resultados para diferentes amostras de leite concordaram com os obtidos por cromatografia líquida de alto desempenho a um nível de confiança de 95% / Melamine is a toxic compound illegally used to adulterate the protein content in milk. The ingestion even of low amounts of melamine can lead to renal complications and death of animals and humans. Usual procedures for the determination of total nitrogen are not selective for the determination of non-protein nitrogen. In this work, a fast and environmentally friendly procedure was developed for the determination of melamine as a milk adulterant. Triton X-114 was used for sample clean-up and as a fluorophore. Determination of melamine was based on fluorescence quenching of surfactant in the poor phase after cloud point extraction in the presence of melamine. A linear response was observed from 1.0 and 6.0 mg L-1 melamine, described by the Stern-Volmer equation I°/I = 0.999 + 0.0165 CMEL(r = 0.999). The detection limit was estimated at 0.8 mg L-1 level (95% confidence level), which enables detection of as low as 320 \'mü\'g in 100 g of melamine of milk. The coefficients of variation (n = 8) were estimated at 0.4 % or 1.4 % in the absence or presence of the analyte, respectively. Recoveries within 95-102 % and similar slopes of calibration graphs obtained with and without milk indicated the absence of matrix effects. The results for different milk samples agreed with those obtained by high performance liquid chromatography at the 95% confidence level

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