Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-02-01T21:27:07Z No. of bitstreams: 1 EmilyCintiaTossiDeAraujoCosta_TESE.pdf: 2216846 bytes, checksum: 5f38e382d8ae3c1bfe9f3db58b62a672 (MD5) / Approved for entry into archive by Elisangela Moura (lilaalves@gmail.com) on 2016-02-02T21:24:40Z (GMT) No. of bitstreams: 1 EmilyCintiaTossiDeAraujoCosta_TESE.pdf: 2216846 bytes, checksum: 5f38e382d8ae3c1bfe9f3db58b62a672 (MD5) / Made available in DSpace on 2016-02-02T21:24:40Z (GMT). No. of bitstreams: 1 EmilyCintiaTossiDeAraujoCosta_TESE.pdf: 2216846 bytes, checksum: 5f38e382d8ae3c1bfe9f3db58b62a672 (MD5) Previous issue date: 2013-09-23 / A contamina??o de ?guas naturais por metais tornou-se assunto de interesse p?blico mundial por serem considerados biocumulativos. A determina??o e o monitoramento de contaminantes met?licos em ?guas ? uma tarefa que deve ser cont?nua e por isto a import?ncia do desenvolvimento, modifica??o e otimiza??o de metodologias anal?ticas capazes de realizar a determina??o dos v?rios contaminantes met?licos em ambientes naturais, pois em muitos casos, a instrumenta??o dispon?vel n?o apresenta sensibilidade anal?tica suficiente para a determina??o de tra?os. Neste estudo, um m?todo de extra??o e pr?-concentra??o utilizando um sistema microemulsionado, no equil?brio de Winsor II foi testado e otimizado para a determina??o dos metais Co, Cd, Pb, Tl, Cu e Ni por Espectrometria de absor??o at?mica de alta resolu??o com fonte cont?nua e atomiza??o em forno de grafite e chama (HR-CS AAS). A otimiza??o do programa de temperatura para o forno de grafite foi realizada atrav?s de curvas de pir?lise e atomiza??o para cada analito sem e com o uso de diferentes modificadores qu?micos. Cd e Pb tiveram condi??es ?timas com modificador permanente Ru, pir?lise em 700?C e atomiza??o em 1700?C, para Tl solu??o Pd/Mg foi o melhor modificador, temperaturas 600?C e 1700?C de pir?lise e atomiza??o, respectivamente e para o Co pir?lise em 800?C e atomiza??o ? 2400?C sem uso de modificador qu?mico, por?m W foi empregado como modificador permanente a fim de se prolongar o tempo de vida ?til do forno. Cu e Ni foram analisados na chama ap?s pr?-concentra??o. Avaliou-se tamb?m fatores que influenciam a efici?ncia de extra??o, atrav?s do efeito salting out. Como compromisso, 6 g L-1 de Na e 1% de HNO3 (v/v) foi definido. Para determina??o do ponto ?timo de extra??o, um planejamento centroide-simplex foi aplicado, sendo escolhido como compromisso as seguintes propor??es: 70% fase aquosa, 10% fase ?leo e 20% Cotensoativo/Tensoativo (C/T = 4). Ap?s extra??o, os metais foram determinados e as Figuras de m?rito obtidas para o m?todo proposto foi: 0,1 a 10 ?g L-1 de faixa linear, LOD 0,094, 0,011, 0,057 e 0,050 ?g L-1 para Pb, Cd, Tl e Co, respectivamente. Testes de adi??o e recupera??o na amostra certificada apresentaram valores de recupera??o ap?s extra??o de 105 e 101% para Pb e Cd, respectivamente, e nas amostras fortificadas a recupera??o para os analitos ficou entre 107 e 108% comprovando que o m?todo proposto pode ser utilizado na extra??o, possibilitou a separa??o dos metais de matrizes complexas, e ainda com bom fator de pr?-concentra??o. / The determination and monitoring of metallic contaminants in water is a task that must be continuous, leading to the importance of the development, modification and optimization of analytical methodologies capab le of determining the various metal contaminants in natural environments, because, in many cases, the ava ilable instrumentation does not provide enough sensibility for the determination of trace values . In this study, a method of extraction and pre- concentration using a microemulsion system with in the Winsor II equilibrium was tested and optimized for the determination of Co, Cd, P b, Tl, Cu and Ni through the technique of high- resolution atomic absorption spectrometry using a continuum source (HR-CS AAS). The optimization of the temperature program for the graphite furnace (HR-CS AAS GF) was performed through the pyrolysis and atomization curves for the analytes Cd, Pb, Co and Tl with and without the use of different chemical modifiers. Cu and Ni we re analyzed by flame atomization (HR-CS F AAS) after pre-concentr ation, having the sample introduction system optimized for the realization of discrete sampling. Salinity and pH levels were also analyzed as influencing factors in the efficiency of the extraction. As final numbers, 6 g L -1 of Na (as NaCl) and 1% of HNO 3 (v/v) were defined. For the determination of the optimum extraction point, a centroid-simplex statistical plan was a pplied, having chosen as the optimum points of extraction for all of the analytes, the follo wing proportions: 70% aqueous phase, 10% oil phase and 20% co-surfactant/surfactant (C/S = 4). After extraction, the metals were determined and the merit figures obtained for the proposed method were: LOD 0,09, 0,01, 0,06, 0,05, 0,6 and 1,5 ?g L -1 for Pb, Cd, Tl, Co, Cu and Ni, re spectively. Line ar ranges of ,1- 2,0 ?g L -1 for Pb, 0,01-2,0 ?g L -1 for Cd, 1,0 - 20 ?g L -1 for Tl, 0,1-5,0 ?g L -1 for Co, 2-200 ?g L -1 and for Cu e Ni 5-200 ?g L -1 were obtained. The enrichment factors obtained ranged between 6 and 19. Recovery testing with the certified sample show ed recovery values (n = 3, certified values) after extraction of 105 and 101, 100 and 104% for Pb, Cd, Cu and Ni respectively. Samples of sweet waters of lake Jiqui, saline water from Potengi river and water produced from the oil industry (PETROBRAS) were spiked and the recovery (n = 3) for the analytes were between 80 and 112% confirming th at the proposed method can be used in the extraction. The proposed method enabled the sepa ration of metals from complex matrices, and with good pre-concentration factor, consistent with the MPV (allowed limits) compared to CONAMA Resolution No. 357/2005 which regulat es the quality of fresh surface water, brackish and saline water in Brazil.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-01-26T17:52:57Z No. of bitstreams: 1 BrenoGustavoPorfirioBezerra_DISSERT.pdf: 1680172 bytes, checksum: 0f4f20935e8e24b12e505645455bea08 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-01-28T19:06:56Z (GMT) No. of bitstreams: 1 BrenoGustavoPorfirioBezerra_DISSERT.pdf: 1680172 bytes, checksum: 0f4f20935e8e24b12e505645455bea08 (MD5) / Made available in DSpace on 2016-01-28T19:06:56Z (GMT). No. of bitstreams: 1 BrenoGustavoPorfirioBezerra_DISSERT.pdf: 1680172 bytes, checksum: 0f4f20935e8e24b12e505645455bea08 (MD5) Previous issue date: 2014-11-03 / A ?gua produzida representa um grande problema associado com a atividade de extra??o de ?leo bruto. O monitoramento dos n?veis de metais nos res?duos ? constante e requer a utiliza??o de t?cnicas anal?ticas sens?veis. No entanto, a determina??o de elementos tra?o muitas vezes pode exigir uma etapa de pr?-concentra??o. O objetivo deste trabalho foi desenvolver um m?todo anal?tico simples e r?pido para a extra??o e pr?-concentra??o baseada no fen?meno de extra??o no ponto nuvem para a determina??o do Cd, Pb e Tl em ?gua produzida amostras por Espectrometria de Absor??o de alta resolu??o com fonte continua e atomiza??o em forno de grafite. Um planejamento Box Behnken foi usado para obter a condi??o ideal de extra??o dos analitos. Os fatores avaliados foram: concentra??o do agente complexante (o,odietilditilfosfato am?nio, DDTP), a concentra??o do ?cido clor?drico e concentra??o do surfactante (Triton X -114). A condi??o ideal de extra??o foi obtida com: 0,6% m v -1 DDTP, HCl 0,3 mol L-1 e 0,2% m v -1 de Triton X - 114 para o Pb; 0,7% m v -1 DDTP, HCl 0,8 mol L-1 e 0,2% m v -1 Triton X-114 para Cd. Para o Tl foi evidenciado que melhor condi??o de extra??o se d? com aus?ncia de DDTP, as condi??es de extra??o foram ent?o HCl 1,0 mol L-1 e 1,0% m v -1 de Triton X - 114. Os limites de detec??o para o m?todo proposto, foram 0,02 ?g L-1 , 0,004 ?g L-1 e 0,06 ?g L-1 para o Pb, Cd e Tl, respectivamente. Os fatores de enriquecimento foram superiores a 10 vezes. O m?todo foi aplicado para a ?gua produzida da bacia Potiguar, e testes de adi??o e recupera??o foram realizados, e valores ficaram entre 81% e 120%. A precis?o foi expressa com desvio padr?o relativo (RSD) foi inferior a 5% / Produced water is a major problem associated with the crude oil extraction activity. The monitoring of the levels of metals in the waste is constant and requires the use of sensitive analytical techniques. However, the determination of trace elements can often require a pre-concentration step. The objective of this study was to develop a simple and rapid analytical method for the extraction and pre-concentration based on extraction phenomenon cloud point for the determination of Cd, Pb and Tl in produced water samples by spectrometry of high resolution Absorption source continues and atomization graphite furnace. The Box Behnken design was used to obtain the optimal condition of extraction of analytes. The factors were evaluated: concentration of complexing agent (o,o-dietilditilfosfato ammonium, DDTP), the concentration of hydrochloric acid and concentration of surfactant (Triton X -114). The optimal condition obtained through extraction was: 0,6% m v-1 DDTP, HCl 0,3 mol L-1 and 0,2% m v-1 of Triton X - 114 for Pb; 0,7% m v-1 DDTP, HCl 0,8 mol L-1 and 0,2% m v-1 Triton X-114 for Cd. For Tl was evidenced that best extraction condition occurs with no DDTP, the extraction conditions were HCl 1,0 mol L-1 e 1,0% m v-1 de Triton X - 114. The limits of detection for the proposed method were 0,005 ?g L-1 , 0,03 ?g L-1 and 0,09 ?g L-1 to Cd, Pb and Tl, Respectively. Enrichment factors Were greater than 10 times. The method was applied to the water produced in the Potiguar basin, and addition and recovery tests were performed, and values were between 81% and 120%. The precision was expressed with relative standard deviation (RSD) is less than 5%