Vera Lúcia Cancio Souza Santos

EspEctromEtria dE absorção atômica: o caminho para dEtErminaçõEs multi- ElEmEntarEs

This paper present an overview of way covered for the spectrometry of atomic absorption (AAS), tracing a line of the historical events in its development and its establishment as a multielement technique. Additionally, the efforts carried by through several researchers in the search for the instrumental evolution, the advances, advantages, limitations, and trends of this approach are related. Several works focusing its analytical applications are cited employing simultaneous multielement determination by flame (FAAS) and/or graphite furnace (GF AAS), and fast sequential multielement determination using FAAS are reported in the present review.

Distribution of trace elements in tissues of shrimp species Litopenaeus vannamei (Boone, 1931) from Bahia, Brazil

In this study, concentrations of trace elements in tissues of shrimp species (Litopenaeus vannamei) from farming and zone natural coastal located in the northeastern Brazil were investigated. The elements determination was performed by optical emission spectrometry with inductively coupled plasma (ICP OES). The following ranges of concentrations in the tissues were obtained in µg g-1 dry weight: Al: 13.4-886.5, Cd: 0.93-1.80; Cu: 24.8-152; Fe: 3.2-410.9; Mn: 0.36-24.4; Se: 0.094-9.81 and Zn: 20.3-109.4. The shrimp muscle can be a good iron source (about 88.9 mg-1g dry weight). The distribution of Se concentration in tissues showed much variation between locations, and the concentration levels found in shrimp muscles of wild samples were high, where its levels in 67% of muscle and 50% of others tissues samples exceeded the ANVISA limit, indicating evidence of selenium bioaccumulation. Significant correlation was observed between the following pairs of elements: Fe-Zn (r= -0.70), Mn-Cu (r= -0.74), Se-Cu (r= -0.68), Se-Mn (r= 0.82) in the muscles; Fe-Al (r= 0.99), Mn-Al (r= 0.62), Mn-Fe (r= 0.62), Se-Al (r = 0.88), Se-Fe (r= 0.87), Se-Mn (r= 0.58) in the exoskeleton and Cu-Zn (r = 0.68), Al-Cu (r= 0.88), Fe-Cu (r= 0.95) and Fe-Al (r= 0.97) in the viscera.

Assessment of essential elements and chemical contaminants in thirteen fish species from the Bay Aratu, Bahia, Brasil

Concentrations of ten elements (Cd, Cr, Cu, Fe, Ni, Pb, Se, Sr, V and Zn) were determinate in muscle tissues of 13 fish species from Aratu Bay, Bahia, Brazil by inductively coupled plasma optical emission spectrometry. The accuracy and precision of our results were checked by using two certified reference materials: BCR-422 cod muscle and SRM 1566b oyster tissue. The average trace element concentrations in the fish species varied in the following ranges, in μg g-1: 0.03-0.8 for Cr; 2.0-33.7 for Cu, 2.4-135.1 for Fe, 1.6-25.6 for Se; 1.6-35.1 for Sr; and 2.8-40.5 for Zn. The Diaptereus rhombeus (carapeba) specie presented the highest concentrations of Se, Cu and Fe. Chromium and Se were present at levels above the limit of tolerance allowed by the National Agency of Sanitary Vigilance (ANVISA). The results were also evaluated using the multivariate analysis techniques: principal component analysis (PCA) and hierarchical cluster analysis (HCA).

Source and distribution of organic matter in surface sediments from mangroves on the island of Itaparica, Bahia/Brazil

Elemental analysis and isotopic composition evaluated the impact of human activity at the surface sediments in the largest island of Todos os Santos Bay, northeastern Brazil. Saturated hydrocarbons (n-alkanes and isoprenoids) by gas chromatography coupled with a flame ionization detector and 13C by mass spectrometer were determined from 30 surface sediment samples in mangroves at the Itaparica Island (Bahia-Brazil) in the rainy and dry season. These data, distribution, and ratio of carbon/nitrogen showed a mixture of sources: continental, marine, and anthropogenic ones. From the chromatographic profiles, light oil contamination was observed in the dry regions of Baiacu, Campinas, and Ponta Grossa, while in Jiribatuba it was observed during the rainy season. However, δ13C results during dry and rainy season in the presence of oil also showed in Misericordia and Cacha Prego districts for both periods and Ponta Grossa during the rainy season. Principal component analysis, using a correlation matrix, revealed the latent relationships among all the surface sediment stations investigated and confirmed our analytical results.

CONCENTRAÇÃO DE METAIS EM SEDIMENTOS DA LAGOA DO PARQUE METROPOLITANO DE PITUAÇU, SALVADOR, BAHIA, BRASIL

A lagoa de Pituacu esta inserida no Parque Metropolitano de Pituacu (PMP). Esta recebe efluentes domesticos e pluviais e encontra-se em um processo acelerado de degradacao ambiental. O presente trabalho teve como objetivo determinar a concentracao de metais pesados (Al, Cu, Fe, Mn, V) em sedimentos superficiais da lagoa do Parque Metropolitano de Pituacu, Salvador, Bahia, Brasil. Foram definidos 7 pontos amostrais. A determinacao de metais (Al, Cu, Fe, Mn e V) foi realizada utilizando a tecnica da espectrometria de emissao optica com plasma indutivamente acoplado (ICP OES). A faixa de concentracoes encontradas para os metais foram: Al (3.618-27.210 mg kg -1 ); Fe (11.968-122.030 mg kg -1 ); Mn (44,00-481,50 mg kg -1 ); V (25,00-111,50 mg kg -1 ) e Cu (4,05-25,50 mg kg -1 ). A ordem de concentracao nos diversos pontos foi Fe>Al>Mn>V>Cu ou Fe>Al>Mn=V>Cu, com as maiores e as menores concentracoes de todos os metais, encontradas nos pontos P1 e P3, respectivamente. Houve variacoes espaciais nas concentracoes dos metais, com maiores concentracoes nos pontos amostrais proximos de atividades antropicas (efluentes e atividade agricola). Esse estudo reporta niveis relativamente altos, especialmente para o V, indicando possiveis necessidades de ampliar acoes de preservacao ou monitoramento ambiental para evitar a acumulacao desses metais em niveis toxicos para a agua e para o sedimento.