Otimização de rotina analítica para elementos traços em sedimento de lagoa por ICP-OES : Lagoa Juara-Serra/ES

• Autor(a) principal: Oliveira, Antonio Carlos de
• Data de Publicação: 2010
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Espírito Santo (riUfes)
• Texto Completo: http://repositorio.ufes.br/handle/10/4653
• topic: ICP-OES; Nebulização; Cadeia alimentar; Rádio freqüência; elementos; concentrações; análises; Química; Elementos traços; Sedimentos lacustres; Quimiometria; Espectrometria de emissão óptica por plasma acoplado indutivamente; 54

This workevaluates the application of the technique of ICP-OES for the determination of trace elements that are environmentally viable in sediment samples from the lake. We investigated the elements As, Ba, Cd, Co, Cr, Cu, Mn, Mo, Ni, Pb, Se, Sr and Zn and Al as a majority element, all measured in the fraction less than 63µm sediment dried at 40°C using a spectrometer in view radial, V-groove nebulizer, a mist chamber Sturman-Master and detection system based on coupled device (CCD). We investigated the robustness of the plasma, pumping speed, pressure in the mist chamber, the power of radio frequency, integration time of the signal. Under optimum conditions was obtained limits of detection (LD)and the limits of quantification ( LQ).Although the present and if the higher LQ's yet these are below the guides Threshold Effects Levels (TEL) and Probable Effects Levels (PEL) established by the Canadian Council of Ministers of the Environment (CCME), which is a reference to the resolution of the National Council on Environment (CONAMA 344). The methodology was developed through the use of Certified Reference Material (CRM) MESS 3 marine sediment, resulting in concentrations consistent with the certified (relative error <10%), except for Al, As and Cd showed relative error on the throne of 12 %. The quality of the results was evaluated considering also the precision (RSD <10%) with As, Cd, Pb and Se only slightly higher than desired, and removal of duplicates that tests showed satisfactory results for all trace elements studied.The sediment of Lake Juara -Serra / ES was characterized by determination of Total Organic Matter (TOM) using the techniques of the oven at 550ºC and thermogravimetric analysis (TA). The result of TOM by heating in a furnace results showed two times higher than that obtained by the derivative of the TA curve. The result of trace elements in sediment and TOM were correlated with turbidity and pH of surface water by Principal Component Analysis (PCA) getting to know the positive and negative correlations between groups of parameters. Observed four groups of parameters positively correlated: Pb, Ni, Ba, Cu, Mo and turbidity; Zn, Cr and Al; Co, Se,As and pH; Sr, Cd and TOM. The group of Cd and Zn were negatively correlated, possibly due to anthropogenic contribution. The Cd that had values above the TEL but belowthe PEL