Comparative study of the atmospheric chemical composition of three South American cities

PM10 samples were collected in 2008 at three sites in South America in the framework of an international project (South American Emissions Megacities, and Climate; SAEMC). The concentration of metals, metalloids, ion and organic compounds of most PM10 samples collected at three sites (Buenos Aires (BAI), Bogotá (BOG) and São Paulo (SPA)) is below the air quality standard of the respective countries. At the sites n-alkanes and carbon preference index distribution indicated the influence of petroleum residues derived from vehicular emissions. Most PAH detected are attributed to light-duty gasoline vehicles and to stationary sources. At all sites benzo[a]pyrene equivalent values mean a significant cancer risk. Sulfate, nitrate, ammonium, calcium and sodium are the most abundant water-soluble ions at the three sites. Ammonium sulfate is likely the form presented for these species formed by photochemical reactions of precursors emitted mainly by vehicles. At BAI and SPA, formate/acetate ratios indicated the contribution of photochemical reactions; on the contrary, at BOG site, acetate is predominant, indicating strong contribution of vehicular emissions. São Paulo samples showed the highest concentrations of elements among all the sites. None of the toxic or potentially toxic elements exceed the guideline values of the World Health Organization. At BAI site earth crust seems to be the major source of Fe and Mn; at SPA, anthropogenic source is responsible for Pb and Zn presences. Traffic related element is well correlated at the three sites.Fil: Vasconcellos, Pérola C.. Universidade de Sao Paulo; BrasilFil: Souza, Davi Z.. Instituto Nacional de Pesquisas Nucleares; BrasilFil: Ávila, Simone G.. Universidade de Sao Paulo; BrasilFil: Araújo, Maria P.. Universidade de Sao Paulo; BrasilFil: Naoto, Edson. Universidade de Sao Paulo; BrasilFil: Nascimento, Kátia H.. Universidade de Sao Paulo; BrasilFil: Cavalcante, Fernando S.. Universidade de Sao Paulo; BrasilFil: Dos Santos, Marina. Comisión Nacional de Energía Atómica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Smichowski, Patricia Nora. Comisión Nacional de Energía Atómica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Behrentz, Eduardo. Universidad de los Andes; Colombi

Structural signatures of water-soluble organic aerosols in contrasting environments in South America and Western Europe

This study describes and compares the key structural units present in water-soluble organic carbon (WSOC) fraction of atmospheric aerosols collected in different South American (Colombia – Medellín and Bogotá, Peru – Lima, Argentina – Buenos Aires, and Brazil – Rio de Janeiro, São Paulo, and Porto Velho, during moderate (MBB) and intense (IBB) biomass burning) and Western European (Portugal – Aveiro and Lisbon) locations. Proton nuclear magnetic resonance (1H NMR) spectroscopy was employed to assess the relative distribution of non-exchangeable proton functional groups in aerosol WSOC of diverse origin, for the first time to the authors’ knowledge in South America. The relative contribution of the proton functional groups was in the order H-C > H–C–C= > H-C-O > Ar-H, except in Porto Velho during MBB, Medellín, Bogotá, and Buenos Aires, for which the relative contribution of H-C-O was higher than that of H-C-C=. The 1H NMR source attribution confirmed differences in aging processes or regional sources between the two geographic regions, allowing the differentiation between urban combustion-related aerosol and biological particles. The aerosol WSOC in Aveiro, Lisbon, and Rio de Janeiro during summer are more oxidized than those from the remaining locations, indicating the predominance of secondary organic aerosols. Fresh emissions, namely of smoke particles, becomes important during winter in Aveiro and São Paulo, and in Porto Velho during IBB. The biosphere is an important source altering the chemical composition of aerosol WSOC in South America locations. The source attribution in Medellín, Bogotá, Buenos Aires, and Lima confirmed the mixed contributions of biological material, secondary formation, as well as urban and biomass burning emissions. Overall, the information and knowledge acquired in this study provide important diagnostic tools for future studies aiming at understanding the water-soluble organic aerosol problem, their sources and impact at a wider geographic scale.Fil: Duarte, Regina M.B.O.. Universidade de Aveiro; PortugalFil: Matos, João T.V.. Universidade de Aveiro; PortugalFil: Paula, Andreia S.. Universidade de Aveiro; PortugalFil: Lopes, Sónia P.. Universidade de Aveiro; PortugalFil: Pereira, Guilherme. Universidade de Sao Paulo; BrasilFil: Vasconcellos, Pérola. Universidade de Sao Paulo; BrasilFil: Gioda, Adriana. Universidade Federal do Rio de Janeiro; BrasilFil: Carreira, Renato. Universidade Federal do Rio de Janeiro; BrasilFil: Silva, Artur M.S.. Universidade de Aveiro; PortugalFil: Duarte, Armando C.. Universidade de Aveiro; PortugalFil: Smichowski, Patricia Nora. Comisión Nacional de Energía Atómica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rojas, Nestor. Universidad Nacional de Colombia; ColombiaFil: Sanchez Ccoyllo, Odon. No especifíca

New constraints on elemental and Pb and Nd isotope compositions of South American and Southern African aerosol sources to the South Atlantic Ocean

Improving the geochemical database available for characterising potential natural and anthropogenic aerosol sources from South America and Southern Africa is a critical precondition for studies aimed at understanding trace metal controls on the marine biogeochemical cycles of the South Atlantic Ocean. We here present new elemental and isotopic data for a wide range of sample types from South America and Southern Africa that are potentially important aerosol sources. This includes road dust from Buenos Aires and lichen samples from Johannesburg, soil dust from Patagonia, volcanic ash from the Andean volcanic belt, and aerosol samples from São Paulo. All samples were investigated for major (Al, Ca, Fe, Mg, Na, K, Mn) and trace element (Cd, Co, Cr, Cu, Ni, Pb, REE, Sc, Th, Y, V, Zn) concentrations and Nd and Pb isotopic compositions. We show that diagrams of 208Pb/207Pb vs. εNd, 208Pb/207Pb vs. Pb/Al, 1/[Pb], Zn/Al, Cd/Al, Cu/Al, and εNd vs. Pb/Al, and 1/[Nd] are best suited to separate South American and South African source regions as well as natural and anthropogenic sources. A subset of samples from Patagonia and the Andes was additionally subjected to separation of a fine (<5 μm) fraction and compared to the composition of the bulk sample. We show that differences in the geochemical signature of bulk samples between individual regions and source types are significantly larger than between grain sizes. Jointly, these findings present an important step forward towards a quantitative assessment of aeolian trace metal inputs to the South Atlantic Ocean

On-line preconcentration and speciation analysis of Cr(III) and Cr(VI) using baker's yeast cells immobilised on controlled pore glass

A study was undertaken to evaluate Saccharonzyces cerevisiae as a substrate for the biosorption of Cr(III) and Cr(VI) aiming to the selective determination of these species in aqueous solutions. The yeast cells were covalently immobilised on controlled pore glass (CPG), packed in a minicolumn and incorporated in an on-line flow injection system. The effect of chemical and physical variables affecting the biosorption process was tested in order to select the optimal analytical conditions for the Cr retention by S. cerevisiae. Cr(III) was retained by the immobilised cells and Cr(VI) were retained by CPG. The speciation was possible by selective and sequential elution of Cr(III) with 0.05 mol L-1 HCl and 2.0 mol L-1 HNO3 for Cr(VI). The influence of some concomitant ions up to 20 mg L-1 was also tested. Quantitative determinations of Cr were carried out by means of inductively coupled plasma optical emission spectrometry (ICP OES). Preconcentration factors of 12 were achieved for Cr(III) and 5 for Cr(VI) when 1.7 mL of sample were processed reaching detection limits of 0.45 for Cr(III) and 1.5 mu g L-1 for Cr(VI). The speciation of inorganic Cr in different kinds of natural waters was performed following the proposed method. Spiked water samples were also analysed and the recoveries were in all cases between 81 and 103%. (c) 2005 Elsevier B.V. All rights reserved

Classification Of Antarctic Algae By Applying Kohonen Neural Network With 14 Elements Determined By Inductively Coupled Plasma Optical Emission Spectrometry

Optical emission spectrometers can generate results, which sometimes are not easy to interpret, mainly when the analyses involve classifications. To make simultaneous data interpretation possible, the Kohonen neural network is used to classify different Antarctic algae according to their taxonomic groups from the determination of 14 analytes. The Kohonen neural network architecture used was 5×5 neurons, thus reducing 14-dimension input data to two-dimensional space. The input data were 14 analytes (As, Co, Cu, Fe, Mn, Sr, Zn, Cd, Cr, Mo, Ni, Pb, Se, V) with their concentrations, determined by inductively coupled plasma optical emission spectrometry in 11 different species of algae. Three taxonomic groups (Rhodophyta, Phaeophyta and Cholorophyta) can be differentiated and classified through only their Cu content. © 2005 Elsevier B.V. All rights reserved.605725730Martens, H., Naes, T., (1989) Multivariate Calibration, , Wiley New YorkMoberg, L., Robertsson, G., Karlberg, B., Spectrofluorimetric determination of chlorophylls and pheopigments using parallel factor analysis (2001) Talanta, 54, pp. 161-170Da Silva, J.C.G.E., Leitão, J.M.M., Costa, F.S., Ribeiro, J.L.A., Detection of verapamil drug by fluorescence and trilinear decomposition techniques (2002) Analytica Chimica Acta, 453, pp. 105-115Pereira-Filho, E.R., Pérez, C.A., Poppi, R.J., Arruda, M.A.Z., Metals distribution and investigation of L'vov platform surface using principal component analysis, multi-way principal component analysis, micro synchrotron radiation X-ray fluorescence spectrometry and scanning electron microscopy after the determination of Al in a milk slurry sample (2002) Spectrochimica Acta, 57, pp. 1259-1276Pereira-Filho, E.R., Sena, M.M., Arruda, M.A.Z., Poppi, R.J., Exploratory analysis of L'vov platform surfaces for electrothermal atomic absorption spectrometry by using three-way chemometric tools (2003) Analytica Chimica Acta, 495, pp. 177-193Tokutaka, H., Yoshihara, K., Fujimura, K., Obu-Cann, K., Iwamoto, K., Surface and interface analysis of GaSb/GaAs semiconductor materials (1999) Applications of Surface Science, 144-145, pp. 59-66Vander Heyden, Y., Vankeerberghen, P., Novic, M., Zupan, J., Massart, D.L., The application of Kohonen neural networks to diagnose calibration problems in atomic absorption spectrometry (2000) Talanta, 51, pp. 455-466Maia, D.R.J., Balbinot, L., Poppi, R.J., De Paoli, M.-A., Effect of conducting carbon black on the photostabilization of injection molded poly(propylene-co-ethylene) containing TiO2 (2003) Polymer Degradation and Stability, 82, pp. 89-98Fidêncio, P.H., Ruisánchez, I., Poppi, R.J., Application of artificial neural networks to the classification of soils from São Paulo state using near-infrared spectroscopy (2001) Analyst, 126, pp. 2194-2200Mazzatorta, P., Vracko, M., Jezierska, A., Benfenati, E., Modeling toxicity by using supervised Kohonen neural networks (2003) Journal of Chemical Information and Computer Sciences, 43, pp. 485-492Zupan, J., Novic, M., Ruisánchez, I., Kohonen and counterpropagation artificial neural networks in analytical chemistry (1997) Chemometrics and Intelligent Laboratory, 38, pp. 1-23Farías, S., Pérez Arisnabarreta, S., Vodopivez, C., Smichowski, P., Levels of essential and potentially toxic trace metals in Antarctic macro algae (2002) Spectrochimica Acta, 57, pp. 2133-2140Haykin, S., (2001) Redes Neurais-Princípios e prática, , 2nd ed. Bookman Porto AlegreMelssen, W.J., Smits, J.R.M., Buydens, L.M.C., Kateman, G., Using artificial neural networks for solving chemical problems: Part II. Kohonen self-organising feature maps and Hopfield networks (1994) Chemometrics and Intelligent Laboratory, 23, pp. 267-291Zupan, J., Gasteiger, J., (1999) Neural Networks in Chemistry and Drug Design, , 2nd ed. Wiley-VCH WeinheimRantanen, J.T., Laine, S.J., Antikainen, O.K., Mannermaa, J.-P., Simula, O.E., Yliruusi, J.K., Visualization of fluid-bed granulation with self-organizing maps (2001) Journal of Pharmaceutical and Biomedical, 24, pp. 343-352Mauseth, J.D., (1998) Botany: An Introduction to Plant Biology, , Jones and Bartlett Publishers SudburySmichowski, P., Farías, S., Valiente, L., Iribarren, M.L., Vocopivez, C., Total As content of nine species of Antarctic macro algae as determined by electrothermal atomic absorption spectrometry (2004) Analytical Bioanalysis Chemistry, 378, pp. 465-469Szolnoki, A.C., Báthori, M., Blunden, G., Determination of elements in algae by different atomic spectroscopic methods (2000) Micochemistry Journal, 67, pp. 39-42Vodopivez, C., Smichowski, P., Marcovecchio, J., Trace metals monitoring as a tool for characterization of Antarctic ecosystems and environmental management. the Argentine Programme at Jubany Station (2001) Environmental Contamination in Antarctica. a Challenge to Analytical Chemistry, pp. 155-180. , S. Caroli P. Cescon D.W.H. Walton Elsevier Amsterda

Use Of Slurry Sampling In The Determination Of Cu And Zn In Antarctic Limpets And Ni In River Sediment By Flame Atomic Absorption Spectrometry [emprego Da Amostragem De Suspensão Na Determinação De Cu E Zn Em Lapa Antártica E Ni Em Sedimento De Rio Por Espectrometria De Absorção Atômica Com Chama]

In order to demonstrate the feasibility of slurry sampling for environmental studies, different methodologies were developed for Cu and Zn in antarctic limpets and Ni in river sediment with FAAS detection. Studies focusing particle size, acid concentration, slurry stability, selectivity, among others were carried out in order to define the better conditions for slurry analysis. A study related to the depth profile for Ni in the Atibaia River sediment was made after optimization conditions for this element. For accuracy check, certified reference material was used as well as decomposition with microwave oven.246756760Ebdon, L., Wilkinson, J.R., (1987) J. Anal. At. Spectrom., 2, p. 325Miller-Ihli, N.J., (1990) Fresenius' J. Anal. Chem., 337, p. 271Cabrera, C., Madrid, Y., Cámara, C., (1994) J. Anal. At. Spectrom., 9, p. 1423Januzzi, G.S.B., Krug, F.J., Arruda, M.A.Z., (1997) J. Anal. At. Spectrom., 12, p. 375Bermejo-Barrera, P., Moreda-Piñero, A., Moreda-Piñero, J., Bermejo-Barrera, A., (1998) Talanta, 45, p. 1147Mierzwa, J., Sun, I.-Ch., Yang, M.-H., (1998) Spectrochim. Acta, 53 B, p. 63Bendicho, C., De Loos-Vollebregt, M.T.C., (1991) J. Anal. At. Spectrom., 6, p. 353Miller-Ihli, N.J., (1992) Anal. Chem., 64, pp. 964AMagalhães, C.E.C., Arruda, M.A.Z., (1998) Quim. Nova, 21, p. 459Brady, D.V., Montalvo, J.G., Jung, J., Curran, R.A., (1974) At. Absorpt. Newslett., 13, p. 118Brady, D.V., Montalvo, J.G., Glowacki, G., Pisciotta, A., (1974) Anal. Chim. Acta, 70, p. 448Stephen, S.C., Littlejohn, D., Ottaway, J.M., (1985) Analyst, 110, p. 1147Arruda, M.A.Z., Gallego, M., Valcárcel, M., (1995) Quim. Anal., 14, p. 17Langmyr, F.J., (1979) Analyst, 104, p. 993Majidi, V., Holcombe, J.A., (1990) Spectrochim. Acta, 45 B, p. 753Miller-Ihli, N.J., (1994) J. Anal. At. Spectrom., 9, p. 1129Willis, J.B., (1975) Anal. Chem., 47, p. 1752Alves, F.L., Smichowski, P., Farías, S., Marrero, J., Arruda, M.A.Z., (2000) J. Braz. Chem. Soc., 11, p. 365Miller-Ihli, N.J., (1988) J. Anal. At. Spectrom., 3, p. 73López-Garća, I., Arroyo-Cortéz, J., Hernandez-Córdoba, M., (1993) Talanta, 40, p. 1677Kurfürst, U., (1998) Solid Sample Analysis, , Springer-Verlag, BerlinBautista, M.A., Pérez-Sirvent, C., López-García, I., Hernandez-Córdoba, M., (1994) Fresenius' J. Anal. Chem., 350, p. 359López-García, I., Sánches-Merlos, M., Hernandez-Córdoba, M., (1996) J. Anal. At. Spectrom., 11, p. 1003López-García, I., Sánches-Merlos, M., Hernandez-Córdoba, M., (1997) Spectrochim. Acta, 52 B, p. 437Price, W.J., (1978) Analytical Atomic Spectrometry, 2nd Ed., , Heyden & Sons Ltd. , LondonNg, K.C., Caruso, J.A., (1983) Analyst, 198, p. 476(1987) Analyst, 112, p. 199Von Gunten, H.R., Sturm, M., Moser, R.N., (1997) Environ. Sci. Technol., 31, p. 219