Determinação seletiva de tributilestanho na presença de Sn(IV) em amostras ambientais usando HG-ICP OES e Saccharomyces cerevisiae como material sorvente

A method for selective determination of tributyltin in the presence of Sn(IV) by combining hydride generation inductively coupled plasma optical emission spectrometry (HG-ICP OES) and solid phase extraction (SPE) using baker's yeast is proposed. The procedure is based on selective retention of TBT by the yeast at pH = 6. Detection limit of 1.9 µg L-1 and quantification limit of 6.3 µg L-1 were obtained. TBT and San(IV) were determined in the range of 0-25 µg L-1 and the proposed approach was applied to analyze river water, sea water and biological extracts, with recoveries of 114, 101 and 86%, respectively

Paper-based diffusive gradients in thin films technique coupled to energy dispersive X-ray fluorescence spectrometry for the determination of labile Mn, Co, Ni, Cu, Zn and Pb in river water

The diffusive gradients in thin films (DGT) technique has shown enormous potential for labile metal monitoring in fresh water due to the preconcentration, time-integrated, matrix interference removal and speciation analytical features. In this work, the coupling of energy dispersive X-ray fluorescence (EDXRF) with paper-based DGT devices was evaluated for the direct determination of Mn, Co. Ni, Cu, Zn and Pb in fresh water. The DGT samplers were assembled with cellulose (Whatman 3 MM chromatography paper) as the diffusion layer and a cellulose phosphate ion exchange membrane (Whatman P 81 paper) as the binding agent. The diffusion coefficients of the analytes on 3 MM chromatography paper were calculated by deploying the DGT samplers in synthetic solutions containing 500 mu g L-1 of Mn. Co, Ni, Cu, Zn and Pb (4 L at pH 5.5 and ionic strength at 0.05 mol L-1). After retrieval, the DGT units were disassembled and the P81 papers were dried and analysed by EDXRF directly. The 3 MM chromatographic paper diffusion coefficients of the analytes ranged from 1.67 to 1.87 x 10(-6) cm(2) s(-1). The metal retention and phosphate group homogeneities on the P81 membrane was studied by a spot analysis with a diameter of 1 mm. The proposed approach (DGT-EDXRF coupling) was applied to determine the analytes at five sampling sites (48 h in situ deployment) on the Piracicaba river basin, and the results (labile fraction) were compared with 0.45 mu m dissolved fractions determined by synchrotron radiation-excited total reflection X-ray fluorescence (SR-TXRF). The limits of detection of DGT-EDXRF coupling for the analytes (from 7.5 to 26 mu g L-1) were similar to those obtained by the sensitive SR-TXRF technique (3.8 to 9.1 mu g L-1). (C) 2012 Elsevier B.V. All rights reserved.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Speciation of lead in seawater and river water by using Saccharomyces cerevisiae immobilized in agarose gel as a binding agent in the diffusive gradients in thin films technique

Saccharomyces cerevisiae immobilized in agarose gel is proposed as a binding agent for the diffusive gradients in thin films (DGT) technique for determination of Pb in river water and seawater. DGT samplers were assembled with the proposed binding agent (25-mm disk containing 20 %, m/v, S. cerevisiae and 3.0 %, m/v, agarose) and a diffusive layer of cellulose (3MM Chr chromatography paper of 25-mm diameter). The effects of some DGT parameters (e.g., immersion time, ionic strength, and pH) were evaluated. Elution of Pb from the binding agent was effectively done with 1.75 mol L-1 HNO3. The deployment curve (between 2 and 24 h) was characterized by a significant uptake of Pb (346 ng Pb h(-1)) and good linear regression (R (2) = 0.9757). The experimental results are in excellent agreement with the predicted theoretical curve for mass uptake. Consistent results were found for solutions with ionic strengths of 0.005 mol L-1 or greater and within a pH range of 4.5-8.5. Interferences from Cu (20:1), Mn (20:1), Fe (20:1), Zn (20:1), Ca (250:1), and Mg (250:1) in Pb retention were negligible. Determination of Pb in spiked river water samples (from the Corumbatai and Piracicaba rivers) performed using the proposed device was in agreement with total dissolved Pb, whereas measurements in seawater suggest that of the various species of Pb present in the samples, only cationic Pb species are adsorbed by the agarose-yeast gel disks. The in situ concentration of Pb obtained at two different sites of the Rio Claro stream (Corumbatai basin) were 1.13 +/- 0.01 and 1.34 +/- 0.04 mu g L-1. For 72-h deployments, a detection limit of 0.75 mu g L-1 was calculated. The combination of inductively coupled plasma optical emission spectroscopy and in situ deployments of DGT samplers during the 72-h period makes possible the determination of labile Pb in river water.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Determination of labile inorganic and organic species of Al and Cu in river waters using the diffusive gradients in thin films technique

The diffusive gradients in thin films (DGT) technique, using a diffusive gel or a restrictive gel, was evaluated for the determination of labile inorganic and organic species of Al and Cu in model synthetic solutions and river water samples. Experiments were performed both in situ and in the laboratory. In the solutions containing Al ions, the major labile fraction consisted of inorganic species. The organic complex fractions were mainly kinetically inert. For the model Cu solutions, the most labile fraction consisted of inorganic species; however, significant amounts of labile organic complexes of Cu were also present. A comparison was made between the results obtained using restrictive gel DGT and tangential flow ultrafiltration (TF-UF). The Cu fraction determined by restrictive gel DGT (corresponding to the "free" ions plus the labile fraction of small molecular size complexes) was larger than that determined by TF-UF (corresponding to all small molecular size ions), suggesting that the techniques exhibited different porosities for discrimination of inorganic species. For the river water samples analyzed in the laboratory, less than 45% of the analytes were present in labile forms, with most being organic species. For the in situ measurements, the labile inorganic and organic fractions were larger than those obtained in the laboratory analyses. These differences could have been due to errors incurred during sample collection and storage. All results were consistent with those found using two different methods, namely, solid-phase extraction and the DGT technique employing the apparent diffusion coefficient.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Multielemental evaluation of garbage bags by EDXRF

Garbage bags have been broadly used for collecting household waste in Brazil and worldwide. Many of these bags are made from recycled polymers, and the presence of harmful elements is a matter of concern. In this study, an energy dispersive X-ray fluorescence (EDXRF) approach for direct analysis of garbage bags is proposed. The concentrations of K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Br, Rb, Sr and Pb were determined in 14 garbage bags of different brands purchased from local markets in Piracicaba, Sao Paulo State, Brazil. The EDXRF technique proved to be an effective technique for multielemental, environmentally friendly and direct garbage bag monitoring. For most samples, Ca and Ti presented at minor concentration ranges and K, Cr, Mn, Fe, Ni, Cu, Zn and Pb at minor and trace levels. The EDXRF limits of quantification were K: 220; Ca: 112; Ti: 42; Cr: 19; Mn: 13; Fe: 9.2; Ni: 5.7; Cu: 5.3; Zn: 5.2; Br: 12; Rb: 20; Sr: 28 and Pb:17 mu gg(-)(1). The samples had variable thicknesses, with a superficial density variation of 1.5 to 23% among the triplicates. The trueness of the method was checked by analysing the National Institute of Standards and Technology standard reference material SRM2783.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Measurements of labile Cd, Cu, Ni, Pb, and Zn levels at a northeastern Brazilian coastal area under the influence of oil production with diffusive gradients in thin films technique (DGT)

In this work, the ability of the diffusive gradients in thin films technique (DGT) was evaluated for monitoring the concentrations, and estimating the availability, of metals at a northeastern Brazilian coastal area under the influence of oil production. Three sites with an average distance between 0 m (EM-1), 100 m (EM-2), and 1000 m (EM-3) of a submarine outfall-I (Guamare RN, Brazil) and another site (GA-1) with an average distance of 12000 m east of Outfall I, near the city of Galinhos, were studied. DGT units were deployed at the same sites in three campaigns from July, 2010 to June, 2011.Effects on the accuracy of analytical results regarding the deployment time, gel porosity, and thickness were evaluated. There was no difference between the measurements obtained with two sets of DGT devices, those assembled with open or restrictive pore gel, respectively, showing that organic metallic species are not present near the submarine outlet. After 21 day deployments in a region (near Submarine Outfall I) that receives produced waters that have been treated, there was evidence of biofilm formation on DGT membranes. However, it was demonstrated that the biofilm interference with DGT measurements was negligible.Data found in this work show that total concentrations of Cd, Cu, Pb, Ni, and Zn in seawater samples collected at sites GA-1 and EM-1 in two campaigns were below 033, 1.67, 0.47, 0.70, 2.86 ng mL(-1) respectively. For the first time, labile levels of Cd, Cu, Pb, Ni, and Zn in an area under the influence of oil production were determined. DGT measurements allowed the verification of the effects of temporal variation on levels of Zn and Ni. There were no effects of spatial variations on levels of Cd, Cu, Ni, Pb, and Zn at the four studied sites, suggesting no contamination of these metals at the northeastern Brazilian coastal area investigated in this work. (C) 2014 Elsevier B.V. All rights reserved.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Evaluation of the genotoxicity of waters impacted by domestic and industrial effluents of a highly industrialized region of So Paulo State, Brazil, by the comet assay in HTC cells

The problems that most affect the quality of the waters of rivers and lakes are associated with the discharges performed in these environments, mainly industrial and domestic effluents inappropriately treated or untreated. The comet assay is a sensitive tool and is recommended for studies of environmental biomonitoring, which aim to determine the genotoxicity potential of water pollutants. This study aimed to assess the genotoxic potential of the Ribeiro Tatu waters, region of Limeira, So Paulo (SP), by the comet assay with mammalian cells (hepatoma tissue culture (HTC)). Water samples were collected along the Ribeiro Tatu at three distinct periods: November 2008, February 2009 and August 2009, and five collection sites were established: P1, source of the stream; P2, site located downstream the urban perimeter of the municipality of Cordeirpolis and after receiving the pollution load of this city; P3, collection site located upstream the urban perimeter of the city of Limeira; P4, urban area of Limeira; and P5, rural area of Limeira, downstream the discharges of the city sewage. The results showed that for the November 2008 collection, there was no water sample-induced genotoxicity; for the February 2009 collection, the sites P1 and P2 were statistically significant in relation to the negative control (NC), and for the August 2009 collection, the site P5 was statistically significant. These results could be explained by the content of different metals during the different seasons that are under the influence of domestic, industrial and agricultural effluents and also due to the seasonality, since the water samples collected in the period of heavy rain (February 2009) presented a higher genotoxicity possibly due to the entrainment of contaminants into the bed of the stream promoted by the outflow of rainwaters. The comet assay showed to be a useful and sensitive tool in the evaluation of hydric resources impacted by pollutants of diverse origins, and a constant monitoring should be done in order to verify the influence of different factors (season, amount of contaminants) in the water quality.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Use of the freshwater crab Trichodactylus fluviatilis to biomonitoring Al and Mn contamination in river water.

Determinations of Al and Mn concentrations in the tissues (gills, hepatopancreas and muscle) of the freshwater crab Trichodactylus fluviatilis and water samples, both collected from sites on tributaries of the Corumbatai River (São Paulo, Brazil) were performed. The Bioaccumulation Factor (BAF), calculated for different sites with respect to the water concentration, ranged from 173-555 for Al and from 636 - 921 for Mn. Dissolved concentrations of Al and Mn in water samples (collected in different sites) were related to the accumulation of these metals in crabs, suggesting that T. fluviatilis is good biomonitor for Al and Mn pollution in aquatic ecosystem

Bioconcentration of Cd and Pb by the River Crab Trichodactylus fluviatilis (Crustacea: Decapoda)

The bioconcentration of cadmium and lead by the freshwater crab Trichodactylus fluviatilis was evaluated. Thirty animals were exposed to 200 mu g L(-1) of cadmium and lead for 7, 14 and 21 days. Both metals were determined in gills, hepatopancreas and muscle after dissection and digestion by inductively coupled plasma optical emission spectrometry. Lead was detected only in gills, but without significant difference among different exposure periods. Cadmium was found in all tissues after exposure. Significant differences among cadmium concentrations in animals exposed for different periods suggest an accumulation process, with concentration stabilized after 14 days. Fractionation of free (or labile) cadmium and cadmium protein (possibly metallothionein) (Cd-P) in gills and hepatopancreas were carried out to assess the cadmium transference and storage in the tissues using a solid phase extraction procedure with Saccharomyces cerevisae. Fractionation of free (or labile) cadmium and cadmium protein (possibly metallothionein) (Cd-P) in animals exposed to 200 mu g L(-1) for 21 days in gills and hepatopancreas were carried to assess the cadmium transference and storage in the tissues using a solid phase extraction procedure with Saccharomyces cerevisae. In gills, cadmium was found mainly in the free form, while in hepatopancreas the metal was found mainly bound to the protein (Cd-P). It may be inferred that, absorbed through gills, cadmium was transferred and stored in the hepatopancreas.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq