Development of the analytical methods for the determination of metals in antifouling paints

In this work, it presents a study involving the use of a new sample preparation method for Al determinations, Ba, Cu, Fe, Li, Mg, Mn, Pb, Sn and Zn in antifouling paints by techniques atomic spectrometry as F AAS and MIP OES. Furthermore, it investigated the capability of the analysis of the antifouling paints by the LIBS technique, which optimization studies were performed scanning and developing a method for the quantitative determination of macroelements. The acid decomposition under reflux system was compared with the calcination procedure based on ASTM standard method with sample mass modification. The conditions for acid decomposition were optimized and performed using 5 mL of HNO3 at a heating temperature of the digester block at 220 ° C for 3 h. The sample preparation time was significantly reduced when compared with the calcination method. The limits of quantification in mg g-1 for the acid decomposition method were 0.09; 0.99 and 0.015 for Cu, Fe and Zn by F AAS, and 0.003; 0.001; 0.030; 0.045; 0.004; 0.016, 0.011; 0.602; 0.120 and 0.044 for Al, Ba, Cu, Fe, Li, Mg, Mn, Pb, Sn and Zn by MIP OES, respectively. The accuracy of the sample preparation method was performed by recovery test and the results varied between 84 and 120% for all analytes in the samples of antifouling paints. Three anti-fouling paints obtained in the local market were analyzed and showed low levels of concentration for the investigated analytes, except for Fe, Cu and Zn, and Cu concentrations were relatively higher, element this used to replace Sn in antifouling paints. The acid decomposition with reflux system proved to be quick, practical, with simplicity and enhanced security when compared to the standard method. Furthermore, LIBS technique has enabled the development of a method for determination of Fe, Cu and Zn, based on serial dilutions of paints with organic solvent and construction of calibration curves based on analytical concentrations defined by F AAS. The results were satisfactory, with only the proviso that the method has a limitation for the determination of low concentrations of Fe.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPESNeste trabalho, apresenta-se um estudo envolvendo o uso de um novo método de preparo de amostras para as determinações de Al, Ba, Cu, Fe, Li, Mg, Mn, Pb, Sn e Zn em tintas anti-incrustantes por técnicas espectrométricas como F AAS e MIP OES. Investigou-se também a potencialidade da análise das tintas anti-incrustantes pela técnica de LIBS, realizando estudos de otimização, varredura e desenvolvimento de um método para as determinações quantitativas dos macros constituintes nas amostras de tintas anti-incrustantes. A decomposição ácida com sistema de refluxo foi comparada com o procedimento de calcinação baseado no método padrão da ASTM, com modificação da massa da amostra. As condições para a decomposição ácida foram otimizadas e realizadas usando apenas 5 mL de HNO3 a uma temperatura de aquecimento do bloco digestor a 220 ° C durante 3 h. O tempo de preparo da amostra foi reduzido significativamente quando comparado com o método de calcinação. Os limites de quantificação, em mg g-1 , para o método de decomposição ácida foram 0,09; 0,99 e 0,015 para Cu, Fe e Zn por F AAS, e 0,003; 0,001; 0,030; 0,045; 0,004; 0,016, 0,011; 0,602; 0,120 e 0,044 para Al, Ba, Cu, Fe, Li, Mg, Mn, Pb, Sn e Zn por MIP OES, respectivamente. A exatidão do método de preparo da amostra foi avaliada por testes de adição e recuperação, e os resultados em sua maioria variaram entre 84 e 120% para todos os analitos nas amostras de tintas antiincrustantes. Três tintas anti-incrustantes obtidas no mercado local foram analisadas e apresentaram baixos níveis de concentrações para os analitos investigados, com exceção de Fe, Cu e Zn, sendo que para Cu as concentrações foram relativamente mais altas, elemento este utilizado em substituição ao Sn nas tintas anti-incrustantes. A decomposição ácida com sistema de refluxo mostrou ser rápida, prática, com simplicidade e maior segurança quando comparada com o método padrão. Por outro lado, a técnica de LIBS permitiu o desenvolvimento de um método para as determinações de Fe, Cu e Zn, baseado em diluições consecutivas das tintas com solvente orgânico e construção de curvas analíticas de calibração baseadas nas concentrações definidas por F AAS. Os resultados obtidos foram satisfatórios, com apenas a ressalva de que o método apresentou uma limitação para a determinação de Fe em baixas concentrações

Third generation antifouling paints: new biocides in the aquatic environment

Submitted by Caroline Silva ([email protected]) on 2012-12-10T17:44:15Z No. of bitstreams: 1 19-RV10415.pdf: 330169 bytes, checksum: 3be5e7fdb7e6961d55bab97638a69aae (MD5)Approved for entry into archive by Michele Fernanda([email protected]) on 2013-03-22T05:14:30Z (GMT) No. of bitstreams: 1 19-RV10415.pdf: 330169 bytes, checksum: 3be5e7fdb7e6961d55bab97638a69aae (MD5)Made available in DSpace on 2013-03-22T05:14:30Z (GMT). No. of bitstreams: 1 19-RV10415.pdf: 330169 bytes, checksum: 3be5e7fdb7e6961d55bab97638a69aae (MD5) Previous issue date: 2011Antifouling agents have been used on vessels and boats since ancient civilizations. Thus, a brief history on the three generations of antifouling paints was provided in the present review. Additionally, information about physic-chemical properties, environmental levels, toxicology and analytical methods was discussed for the 16 “new” booster biocides used as third-generation antifouling paints. The main problems, limitations and future trends related to this subject were also presented. Finally, actions were suggested in order to appraise the current status of the environmental impact caused by these compounds in South America

Tintas anti-incrustantes de terceira geração: novos biocidas no ambiente aquático

Antifouling agentshave been used on vessels and boats since ancient civilizations. Thus, a brief history on the three generations of antifouling paints was provided in the present review. Additionally, information about physic-chemical properties, environmental levels, toxicology and analytical methods was discussed for the 16 “new” booster biocides used as third-generation antifouling paints. The main problems,limitations and future trends related to this subject were also presented. Finally, actions were suggested in order to appraise the current status of the environmental impact caused by these compounds in South America

Active carbon preparation from treads of tire waste for dye removal in waste water

Bandas de rodagem de sucatas de pneus apresentam baixos teores de cargas inorgânicas e grande quantidade de negro de fumo em sua formulação. Neste trabalho, esse material foi tratado com hidróxido de potássio e cloreto de zinco e, em seguida, realizou-se a pirólise a 500 e 700 °C. Foi investigado o desempenho dos produtos na remoção dos corantes azul de metileno e alaranjado de metila em condições ambientais de pH e concentração. Carbonos obtidos com KOH e pirólise a 700 °C apresentam uma melhor capacidade de adsorção. A simulação deste processo permitiu a caracterização dos gases que contribuem para o desenvolvimento da superfície. Os produtos obtidos apresentam estrutura mesoporosa e estreita distribuição no tamanho de partícula. A presença de contaminantes oriundos desses carbonos foi investigada em meio aquoso. A ausência de zinco e enxofre e o excelente desempenho para remoção de corantes fazem esses materiais úteis no tratamento de água.Treads of scrap tires present low contents of inorganic fillers and a large amount of carbon black. In this work, this material was treated with potassium hydroxide and zinc chloride followed by pyrolysis at 500 and 700 °C. The ability to remove methylene blue and methyl orange were investigated under environmental conditions of pH and concentration. Carbons obtained with KOH at 700 °C present superior adsorption capacity. A simulation of this process permitted the characterization of the gases which contributed to surface development. The obtained products present a mesoporous structure and narrow particle size distribution. The presence of contaminants originated from these carbons was investigated in the aqueous media. The absence of zinc and sulfur releasing and the excellent ability to remove organic dye make these materials useful in the treatment of waste water

Transesterification of castor oil assisted by microwave irradiation

Microwave assisted transesterification of castor bean oil was carried out in the presence of methanol or ethanol, using a molar ratio alcohol/castor bean oil of 6:1, and 10% w/w of acidic silica gel or basic alumina (in relation to the oil mass) as catalyst. Under acid catalysis, the reaction occurred with satisfactory yields using H2SO4 immobilized in SiO2 , methanol under conventional conditions (60 C for 3 h) as well as using microwave irradiation for 30 min. The best results were obtained under basic conditions (Al2O3/50% KOH) using methanol and conventional (60 C, stirring, 1 h) or microwave conditions (5 min). In comparison with conventional heating, the catalyzed alcoholysis assisted by microwaves is much faster and leads to higher yields of the desired fatty esters

Active carbon preparation from treads of tire waste for dye removal in waste water

Bandas de rodagem de sucatas de pneus apresentam baixos teores de cargas inorgânicas e grande quantidade de negro de fumo em sua formulação. Neste trabalho, esse material foi tratado com hidróxido de potássio e cloreto de zinco e, em seguida, realizou-se a pirólise a 500 e 700 °C. Foi investigado o desempenho dos produtos na remoção dos corantes azul de metileno e alaranjado de metila em condições ambientais de pH e concentração. Carbonos obtidos com KOH e pirólise a 700 °C apresentam uma melhor capacidade de adsorção. A simulação deste processo permitiu a caracterização dos gases que contribuem para o desenvolvimento da superfície. Os produtos obtidos apresentam estrutura mesoporosa e estreita distribuição no tamanho de partícula. A presença de contaminantes oriundos desses carbonos foi investigada em meio aquoso. A ausência de zinco e enxofre e o excelente desempenho para remoção de corantes fazem esses materiais úteis no tratamento de água.Treads of scrap tires present low contents of inorganic fillers and a large amount of carbon black. In this work, this material was treated with potassium hydroxide and zinc chloride followed by pyrolysis at 500 and 700 °C. The ability to remove methylene blue and methyl orange were investigated under environmental conditions of pH and concentration. Carbons obtained with KOH at 700 °C present superior adsorption capacity. A simulation of this process permitted the characterization of the gases which contributed to surface development. The obtained products present a mesoporous structure and narrow particle size distribution. The presence of contaminants originated from these carbons was investigated in the aqueous media. The absence of zinc and sulfur releasing and the excellent ability to remove organic dye make these materials useful in the treatment of waste water