Karina Santos Garcia

Determination of total arsenic and arsenic (III) in phosphate fertilizers and phosphate rocks by HG-AAS after multivariate optimization based on Box-Behnken design

In the present paper, a procedure for the determination of total arsenic and arsenic (III) in phosphate fertilizers and phosphate rocks by slurry sampling (SS) with hydride generation atomic absorption spectrometry (HG-AAS) is proposed. Arsenic (III) is determinated directly and total arsenic is determinated after reduction reaction. The procedure was optimized for the flow rate of NaBH(4), NaBH(4) and hydrochloric acid concentrations using a full two-level factorial and also a Box-Behnken design. Slurry preparation with hydrochloric acid in an ultrasonic bath allowed the determination of arsenic (III) with limits of detection and quantification of 0.1 and 0.3 microg L(-1), respectively. The precision of results, expressed as relative standard deviation (RSD), was always lower than 3%. The accuracy of this method was confirmed by analysis of certified sediment reference materials, while the procedure also allows for calibration using aqueous external standards. This method (SS/HG-AAS) was used to determine total arsenic and arsenic (III) in two phosphate rock samples and two phosphate fertilizer samples. In these samples, total arsenic concentrations varied from 5.2 to 20.0 mg kg(-1), while As (III) concentrations varied from 2.1 to 5.5 mg kg(-1), in agreement with published values. All samples were also analyzed using acid digestion/HG-AAS. Both, a paired t-test and a linear regression model demonstrated no significant difference (95% CL) between the results obtained using these two sample preparation procedures.

Assessment of carcinogenic heavy metal levels in Brazilian cigarettes.

Several studies have associated high cancer incidence with smoking habits. According to IARC, lead (Pb), cadmium (Cd), arsenic (As), nickel (Ni), and chromium (Cr) are carcinogenic to humans. These metals are present in cigarettes and their levels vary according to geographical region of tobacco cultivation, fertilizer treatment, plant variety etc. This study aims to assess these metal levels in cigarettes commercialized in Brazil. Three cigarettes of each 20 different brands were individually weighed, the tobacco filling removed, and homogenized. After desiccation, samples were subjected to microwave-assisted digestion. Analyses were performed by graphite furnace atomic absorption spectrometry. Mean levels for Pb, Cd, As, Ni, and Cr were, respectively, 0.27 ± 0.054, 0.65 ± 0.091, 0.09 ± 0.024, 1.26 ± 0.449, and 1.43 ± 0.630, in micrograms per gram of tobacco. No correlation was observed between Cd and any other metal analyzed. A mild correlation (r = 0.483, p < 0.05) was observed between Pb and Cr levels. Strong significant (p < 0.01) correlations were observed between Ni and Cr (r = 0.829), Ni and As (r = 0.799), Ni and Pb (r = 0.637), and between Cr and As (r = 0.621). Chromium and Ni levels were significantly higher in cigarettes from a multinational manufacturer. Our results show a high variability in heavy metal levels in cigarettes, representing an important exposure source of smokers and passive smokers to carcinogenic substances.

Inorganic As speciation and bioavailability in estuarine sediments of Todos os Santos Bay, BA, Brazil.

The spatial distribution of As (total As, As (III) and As (V)) in estuarine sediments from the main tributaries of Todos os Santos Bay, BA, Brazil, was evaluated under high and low flow conditions. The concentrations of As were determined using a slurry sampling procedure with hydride generation atomic absorption spectrometry (HG-AAS). The highest concentrations were observed at estuary mouths, and exceeded conservative lower threshold value (Threshold Effects Level; TEL). Due to the oxic conditions and abundance of Mn and Fe (oxyhydr)oxides in the sediments, most inorganic arsenic in the Subaé and Paraguaçu estuaries was present as As (V). Nevertheless, the concentration of As (III) at several locations along the Jaguaripe River were also above the TEL value, suggesting that As may be toxic to biota. In the Subaé estuary, antropogenic activities are the main source of As. At the Jaguaripe and at Paraguaçu estuaries, nevertheless, natural sources of As need to be considered to explain the distribution patterns.

Sensitivity of the marine benthic copepod Tisbe biminiensis (copepoda, harpacticoida) to potassium dichromate and sediment particle size

For the future use of the marine benthic copepod Tisbe biminiensis in solid-phase sediment toxicological bioassays, the present study investigated the effect of muddy sediment from the Maracaipe estuary (northeastern Brazil), sediment particle size and the reference toxicant potassium dichromate on the species. Muddy sediment from Maracaipe can be used as control sediment, since it does not interfere in the copepod life-cycle and has metal contamination levels that are unlikely to produce any detrimental biological effects on benthic invertebrates. Neither survival nor fecundity was affected by grain size, suggesting that this species can be used with any kind of sediment from muddy to sandy. The sensitivity of T. biminiensis to K2Cr2O7 in acute tests was similar to that of other organisms. The LC50 (lethal concentration to 50% of the test organisms) medium values for T. biminiensis were 7.51, 4.68 and 3.19 mg L-1 for Cr in 48, 72 and 96 h, respectively. These results suggest that T. biminiensis is a promising organism for use in solid-phase sediment toxicity assessments.

Relationship of metal content and bioavailability with benthic macrofauna in Camamu Bay (Bahia, Brazil)

Camamu Bay (Bahia, Brazil) is an Environmental Protected Area with mangroves of economic and ecological importance. The objective of this study was to elucidate, through the distribution of the benthic macrofauna and its relationships with trace metals and bioavailabilty, if the current quality of the mangrove sediments of Camamu Bay is acceptable for the protection of aquatic life. Seven sampling stations were selected as representative of the meso-littoral region of Camamu Bay. It was found 581 macrobenthic organisms distributed in 38 species. The highest values of metals occurred at stations located in areas that influenced by barite extraction, while the lowest concentrations were found in areas with relatively lower anthropogenic influence. Analysis of acid volatile sulphide and simultaneously extracted metals showed the occurrence of the ratio SEM/AVS >1, indicative of possible bioavailability of metals, at only one station. The results suggested that Camamu Bay is a nearly pristine area.

Distribution and sources of polycyclic aromatic hydrocarbons in the aquatic environment: a multivariate analysis

Nesse trabalho, 14 dos hidrocarbonetos policiclicos aromaticos (HPA) incluidos pelo Environmental Protection Agency (EPA) na lista de poluentes prioritarios foram analisados atraves de cromatografia gasosa com espectrometria de massas acoplada (GC-MS). A amostragem das aguas superficiais foi realizada no estuario do rio Paraguacu e do rio Jaguaripe (Bahia), nordeste do Brasil. Concentracoes totais de HPAs variaram de 0,0029 a 0,1079 ng/L em aguas superficiais (rios principais, afluentes), com valor medio de 0,0344 ng/L. Tais concentracoes podem ser tomadas como valores-base para a regiao estudada. Os perfis de HPAs foram dominados por HPAs de baixo peso molecular (dois ou tres aneis de componentes) em amostras de agua superficial. Isto e indicativo de sua origem a partir de oleo ou contaminacao residual (entrada petrogenica). Os dados recolhidos mostram que entrada petrogenica foi predominante em quase todas as estacoes investigadas. Para discriminar diferencas e semelhancas entre as amostras, a analise de componente principal (ACP) foi realizada utilizando uma matriz de correlacao. A ACP revelou as relacoes entre todas as aguas superficiais das estacoes investigadas.

GEOCHEMICAL CORRELATIONS BETWEEN PETROLEUM SAMPLES FROM THE POTIGUAR BASIN AND DEFINITION OF THEIR POSSIBLE GENERATING ROCKS

Jeferson Cavalcante Alvesa, Rennan Geovanny Oliveira Araujoa,b,*,#, Eliane Soares de Souzac, Sarah Adriana Rocha Soaresa, José Roberto Cerqueiraa, Karina Santos Garciaa, Antonio Fernando de Souza Queiroza, Maria Goreti Rodrigues Valed e Aline Rocha Borgese Núcleo de Estudos Ambientais, Instituto de Geociências, Universidade Federal da Bahia, Campus de Ondina, Rua Barão de Jeremoabo, s/n – Ondina, 40170-110 Salvador – BA, Brasil Departamento de Química Analítica, Instituto de Química, Universidade Federal da Bahia, Campus Ondina, Rua Barão de Jeremoabo, 147 – Ondina, 40170-115 Salvador – BA, Brasil Laboratório de Engenharia e Exploração de Petróleo, Centro de Ciências e Tecnologia, Universidade Estadual do Norte Fluminense, Rodovia Amaral Peixoto Km 163, Avenida Brennand s/n – Imboacica, 27925-310 Macaé – RJ, Brasil Instituto de Química, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, 91501-790 Porto Alegre – RS, Brasil Instituto Federal do Paraná, Campus Palmas, 85555-000, Palmas – PR, Brasil

DISTRIBUIÇÃO DE ELEMENTOS TRAÇO EM TECIDOS DE Goniopsis cruentata (LATREILLE, 1803) CAPTURADOS NOS MANGUEZAIS DO SUL DA BAHIA - BRASIL E AVALIAÇÃO DO POTENCIAL DE RISCO NO CONSUMO

DISTRIBUTION OF TRACE ELEMENTS IN TISSUES OF Goniopsis cruentata (LATREILLE, 1803) CAUGHT FROM SOUTH OF BAHIA/ BRAZIL MANGROVES AND POTENTIAL OF RISK ASSESSMENT IN CONSUMPTION. The concentrations of trace metals Ba, Cd, Co, Cr, Cu, Mn, Mo, Ni, Pb, Zn and V were measured in gills, muscle and hepatopancreas of G. cruentata caught from South of Bahia in order to assess the potential health risk by the consumption of mangrove crabs. The highest metal concentrations in gills, and hepatopancreas were Cu, and Zn in muscles, while the lowest metal concentration in three tissues was Cd and Mo. With the results, it is possible to suggest that the high concentrations of some elements, especially of the Cu, may present risks to the Aratu consumers of the mangrove areas studied, or to other populations where these animals may be transported, same for other cities. The mean concentration of Pb in gills in Una and Jequitinhonha is above the value allowed by the legislation, 3,08 μg g and 3,49 μg g, respectively. The concentration of Mn in the females in the three estuaries studied was 1.5 to 4.2 times higher than in the males. In general, detected mean metal concentrations in crab tissues were (in decreasing order) gills > hepatopancreas > muscles. Through the PCA analysis, differentiation between the tissues studied was observed due to its elemental composition. The target hazard quotient (QR) of all trace metals in muscle was less than 1.0 of the provisional tolerable daily intake (IDE) adopted by the USEPA. These results imply that G. cruentata caught from South of Bahia do not have an adverse impact on the consumer health.

Indicadores geoquímicos de contaminação por compostos orgânicos voláteis em águas subterrâneas da Bacia do Rio Lucaia, Salvador, Bahia

Geochemical indicators of contamination by volatile organic compounds in groundwater on Lucaias River Basin, Salvador, Bahia, Brazil. This work investigated the groundwater contamination of the Lucaias River Basin, Salvador, Brazil, for petroleum hydrocarbons leaking from fuel tanks. The concentrations of benzene, toluene, ethylbenzene and xylenes ― BTEX ―, sulfate, nitrate and iron (II) was determined in 17 samples of groundwater. The concentration of BTEX ranged from 0.2 to 185.7 µg.L -1 and the concentrations of sulfate, nitrate and iron (II) were correlated with levels of BTEX undergoing natural degradation. In only two points BTEX levels were observed far above the permitted by CONAMA Resolution no 396/2008, while the others were below the detection limit.