Chemometrics in fuel science: demonstration of the feasibility of chemometrics analyses applied to physicochemical parameters to screen solvent tracers in Brazilian commercial gasoline

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Composição química de Aegiphila sellowiana Cham. (Verbenaceae)

Este trabalho contribui para a caracterização química de Aegiphila sellowiana Cham. (Verbenaceae). As partes aéreas da planta foram extraídas corn solventes orgânicos e fracionadas cromatograficamente. As frações resultantes foram analisadas por rnétodos espectrométricos, fornecendo hidrocarbonetos alifáticos lineares, estigmasterol, α-amirina e o verbascosideo.

Determinação de benzeno, tolueno, etilbenzeno e xilenos em gasolina comercializada nos postos do estado do Piauí

Automotive gasoline consists of a complex mixture of flammable and volatile hydrocarbons derived from crude oil with carbon numbers within the range of 4-12 and boiling points range of 30-225 ºC. Its composition varies with the kind of crude oil and the type of refinery process that they undergone. Aromatics hydrocarbons, in particular benzene, toluene, ethylbenzene and isomeric xylenes (BTEX) are the toxic group constituents presents. GC-FID was employed to quantify these hydrocarbons in 50 commercial gasoline samples from Piauí state. Statistical analysis techniques, such as PCA and HCA were used to analyze the data. Moreover, several validation parameters were evaluated.

Biodegradation of oil refinery residues using mixed-culture of microorganisms isolated from a landfarming

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Comportamento fotofísico do antraceno em sistemas micro-heterogêneos argila-surfactantes-íons metálicos

Argilas constituem uma classe de complexos micro-heterogêneos e podem ser utilizados como substrato para adsorção. O seu comportamento de sorção em fase sólida intensificada pela presença de surfactantes, argilas organofílicas, é um importante fenômeno explorado pela tecnologia ambiental para a remoção de compostos orgânicos policíclicos (hidrocarbonetos aromáticos policíclicos, HPA) da água, introduzidos no ambiente por fontes antropogênicas. Este trabalho tem por objetivo estudar o comportamento fotofísico do antraceno, como modelo de HPA, em sistemas micro-heterogêneos argila-surfactantes-íons metálicos (M(II)= Cd(II), Cu(II), Hg(II), Ni(II) e Pb(II); surfactantes: CTACl; SDS; TR-X100). Os estudos foram conduzidos pelo monitoramento na mudança das propriedades de fluorescência estática e na supressão da emissão do antraceno utilizado como sonda fluorescente. Como supressores foram utilizados os cátions metálicos: Cd(II), Cu(II), Hg(II), Ni(II) e Pb(II). O perfil do espectro de fluorescência e os resultados dos ensaios de supressão da fluorescência da sonda permitiram inferir na localização do sítio de solubilização do antraceno nos sistemas micro-heterogêneos estudados e na conseqüente organização dos mesmos.

Imageamento Elétrico 3D em área contaminada por hidrocarbonetono polo industrial de Cubatão - SP

Este trabalho mostra os resultados obtidos com ensaios geofísicos realizados em uma área contaminada por hidrocarboneto no Polo Industrial de Cubatão - São Paulo, com objetivo de caracterizar as anomalias geoelétricas associadas à presença dos hidrocarbonetos, bem como delimitar e cubar tais anomalias. Para tanto, utilizou-se o método da eletrorresistividade, por meio das técnicas de Sondagem Elétrica Vertical (SEV) e Imageamento Elétrico 3D. Os resultados obtidos permitem indicar que a presença de hidrocarboneto está associada a anomalias condutivas devido aos produtos da biodegradação. As anomalias condutivas ocorrem de forma disseminada na área, totalizando um volume de 1365,3 m³; entretanto, este volume corresponde somente à presença de contaminante em fase residual.

n-alkanes from Paepalanthus Mart. species (Eriocaulaceae)

Este trabalho apresenta o estudo de substâncias apolares obtidas a partir de plantas pertencentes ao gênero Paepalanthus Mart. (Eriocaulaceae). Hidrocarbonetos alifáticos de cadeias longas lineares foram identificados por CG-DIC e CG-EM. Os resultados indicam que as espécies de Paepalanthus subg. Platycaulon apresentam perfil homogêneo, com cadeias carbônicas de n-alcanos variando de C25 a C31, com a maioria das amostras apresentando freqüências maiores dos homólogos C27 e C29. As espécies do subgênero Paepalocephalus podem ser diferenciadas pela distribuição dos n-alcanos principais. P. macrocephalus, uma espécie da subseção Aphorocaulon, apresenta perfil com alcanos de cadeia ímpar, enquanto P. denudatus e P. polyanthus, espécies da seção Actinocephalus, apresentam perfil bem distinto, com grande número de cadeias mais curtas e alta freqüência de cadeias com número par de carbonos, especialmente P. polyanthus. Os resultados obtidos indicam que a distribuição de nalcanos pode ser útil como caráter taxonômico, assim como as substâncias mais polares, como os flavonóides glicosilados.

Effects of genetic polymorphisms CYP1A1, GSTM1, GSTT1 and GSTP1 on urinary 1-hydroxypyrene levels in sugarcane workers

Sugarcane workers in Brazil are exposed to various genotoxic compounds, including polycyclic aromatic hydrocarbons (PAHs), derived from an incomplete combustion process of burnt sugarcane fields. The effects of the occupational exposure to sugarcane fields burning were measured in urine samples of sugarcane workers from the northwest of the State of São Paulo when exposed (harvesting) and when non-exposed (non-harvesting). The urinary levels of 1-hydroxypyrene (1-OHP) and the influence of the genetic polymorphisms CYP1A1, GSTM1, GSTT1 and GSTP1 were evaluated. Our results showed that the 1-OHP levels were significantly higher (P < 0.0000) in the exposed sugarcane workers (0.318 mu mol mol(-1) creatinine) than in the non-exposed workers (0.035 mu mol mol(-1) creatinine). In an unvaried analysis, no influence regarding the polymorphisms was observed. However, multivariate regression analysis showed that the CYP1A1*4 polymorphism in the exposed group, and age and the GSTP1 polymorphism in the non-exposed group significantly influenced urinary 1-OHP excretion levels (P < 0.10). The same group of sugarcane workers was significantly more exposed to PAHs during the harvesting period than during the non-harvesting period. (c) 2006 Elsevier B.V. All rights reserved.

Screening and confirmation of PAHs in vegetable oil samples by use of supercritical fluid extraction in conjunction with liquid chromatography and fluorimetric detection

A fast, simple, non-destructive method for the direct screening of polycyclic aromatic hydrocarbons (PAHs) in vegetable oil samples is proposed. The method uses a supercritical fluid extraction (SFE) system coupled on-line with a fluorimetric detector to determine PAHs. This special assembly avoids the main problems encountered in the determination of PAHs in complex matrices such as vegetable oils. PAHs are selectively extracted by using silica gel in the thimble and cleaned up by passage through a C18 column. Interferences are preferentially retained by the silica gel during the SFE process while PAHs are adsorbed in the C18 column and the remainder of the matrix is sent to waste. Finally, the C18 column is purged to remove residual CO2 gas and adsorbed PAHs are recovered by desorption with a solvent. The extracts from positive samples are subsequently analyzed by liquid chromatography (LC) with fluorescence detection. The proposed method allows the confirmation of vegetable oil safety and hence provides a new tool for consumer protection. (C) 2004 Elsevier B.V. All rights reserved.

OXIDES AS HETEROGENEOUS PROMOTERS FOR LIQUID-PHASE HYDROCARBONYLATION REACTIONS WITH IODOCARBONYLRUTHENIUM CATALYSTS

Basic or acid oxides, used as heterogeneous promoters of carbonylruthenium catalysts in liquid-phase hydrocarbonylation reactions on oxygenated substrates, strongly affect the activity and selectivity of the catalytic system. Concurrent or successive reactions of simple carbonylation, homologation, hydrogenation to hydrocarbons, and etherification take place to varying extents. Carbonylation and etherification are favored by acid oxides and homologation and hydrogenation by basic oxides. This behavior is related to the formation and stabilization by the oxides of H+ and H- hydridocarbonylruthenium catalytic species, whose relative concentrations in solution depend on the nature of the oxide. Heterogeneous oxides are easily separated and recycled from the reaction mixture. Their use simplifies the catalytic system and allows one to direct the catalytic process toward the target product.

Solid-phase extraction of sugar cane soot extract for analysis by gas chromatography with flame ionisation and mass spectrometric detection

The incomplete combustion of biomass is one of the most important sources of emissions of organic compounds into the atmosphere, like polycyclic aromatic hydrocarbons (PAHs) which show genotoxic activity. Since environmental samples generally contain interferents and trace amounts of PAHs of interest, concentration and clean-up procedures are usually required prior to the final chromatographic analysis. This paper discusses the performance of Sep-Pak cartridges (silica gel and RP18) on clean-up of sugar cane soot extract. The best results were obtained with a silica Sep-Pak cartridge. The recoveries ranged from 79% (benzo[b]fluoranthene) to 113% (benzo[e]pyrene). (C) 2000 Elsevier B.V. B.V. All rights reserved.

Integrated assessment of multilevel biomarker responses and chemical analysis in Mussels from Sao Sebastiao, São Paulo, Brazil

The aim of the present study was to investigate the presence of contaminants in the mussel Perna perna from Sao Sebastiao Channel, São Paulo, Brazil, and to evaluate the effects of these contaminants on these organisms at biochemical (catalase [CAT], glutathione-S-transferase [GST], and cholinesterase [ChE]), cellular (neutral red retention time [NRRT] assay), and physiological (cardiac monitoring) levels. Two sampling surveys were performed (winter of 2001 and summer of 2002) at six stations along the channel: Cigarras, station 1; late Clube de Ilhabela, station 2; Oil Terminal, station 3; Toque Toque, station 4; Ponta da Sela, station 5 (reference station); and Taubate, station 6. Differences in CAT activity were observed between mussels from stations 3 and 5 during the winter, but no differences were detected in the summer. No differences in GST activity were found among stations during the winter, although animals from station 3 showed higher activity during the summer. The ChE activity was significantly higher in the mussels from stations I and 2 during the winter and from stations I and 3 during the summer. Organisms from stations I through 4 showed statistically lower NRRT in both seasons. Similar heart rates were observed in the mussels from all stations. Hydrocarbons were detected in organisms from all the stations in both seasons. During the winter, higher polycyclic aromatic hydrocarbon (PAH) levels were observed in organisms from station 3, whereas during the summer, higher levels of metals were found in organisms from stations 1, 3, and 4. The multivariate analyses showed a strong influence of PAHs on the winter biological results, but metals showed higher influence on these responses in the summer, indicating multiple contaminant sources.

Comparative sediment quality assessment in different littoral ecosystems from Spain (Gulf of Cadiz) and Brazil (Santos and Sao Vicente estuarine system)

The goal of this work was to establish comparisons among environmental degradation in different areas from Southern Spain (Gulf of Cadiz) and Brazil (Santos and Sao Vicente estuary), by using principal component analyses (PCA) to integrate sediment toxicity (amphipods mortality) and chemical-physical data (Zn, Cd, Pb; Cu, Ni, Co, V, PCBs, PAHs concentrations, OC and fines contents). The results of PCA extraction of Spanish data showed that Bay of Cadiz, CA-1 did not present contamination or degradation; CA-2 exhibited contamination by PCBs, however it was not related to the amphipods mortality. Ria of Huelva was the most impacted site, showing contamination caused principally by hydrocarbons, in HV-1 and HV-2, but heavy metals were also important contaminants at HV-1, HV-2 and HV-3. Algeciras Bay was considered as not degraded in GR-3 and -4, but in GR-3' high contamination by PAHs was found. In the Brazilian area, the most degraded sediments were found in the stations situated at the inner parts of the estuary (SSV-2, SSV-3, and SSV-4), followed by SSV-6, which is close to the Submarine Sewage Outfall of Santos - SSOS. Sediments from SSV-1 and SSV-5 did not present chemical contamination, organic contamination or significant amphipod mortality. The results, of this investigation showed that both countries present environmental degradation related to PAHs: in Spain, at Ria of Huelva and Gudarranque river's estuary areas; and in Brasil, in the internal portion of the Santos and Sao Vicente estuary. The same situation is found for heavy metals, since all of the identified metals are related to toxicity in the studied areas, with few exceptions (V for both Brazil and Spain, and Cd and Co for Brazilian areas). The contamination by PCBs is more serious for Santos and Sao Vicente estuary than for the investigated areas in Gulf of Cadiz, where such compound did not relate to the toxicity. (c) 2006 Elsevier Ltd. All rights reserved.

Chemical structure, surface properties and biological activities of the biosurfactant produced by Pseudomonas aeruginosa LBI from soapstock

Pseudomonas aeruginosa LBI isolated from petroleum-contaminated soil produced rhamnolipids (RLLBI) when cultivated on soapstock as the sole carbon source. HPLC-MS analysis of the purified culture supernatant identified 6 RL homologues (%): R-2 C-10 C-10 28.9; R-2 C-10 C-12:1 23.0; R-1 C-10 C-10 23.4; R-2 C-10 C-12 11.3; R-2 C-10 C-12 7.9; R-2 C-10 C-12 C-12 5.5. To assess the potential antimicrobial activity of the new rhamnolipid product, RLLBI, its physicochemical properties were studied. RLLBI had a surface tension of 24 mN m(-1) and an interfacial tension 1.31 mN m(-1); the cmc was 120 mg l(-1). RLLBI produced stable emulsions with hydrocarbons and vegetable oils. This product showed good antimicrobial behaviour against bacteria: MIC for Bacillus subtilis, Staphylococcus aureus and Proteus vulgaris was 8 mg l(-1), for Streptococcus faecalis 4 mg l(-1), and for Pseudomonas aeruginosa 32 mg l(-1). RLLBI was active against phytopathogenic fungal species, MIC values of 32 mg l(-1) being found against Penicillium, Alternaria, Gliocadium virens and Chaetonium globosum. Due to its physicochemical properties and antimicrobial behaviour, RLLBI could be used in bioremediation treatment and in the food, cosmetic and pharmaceutical industries.

Carboxylic acids of marine evaporitic oils from Sergipe-Alagoas Basin, Brazil

A. suite of 10 different marine evaporitic oil samples from Sergipe-Alagoas Basin, Brazil was studied for its biomarker content, in particular its acidic constituents. The oils showed different molecular distributions and relative abundances of n-alkanoic, isoprenoid and hopanoic acids. The observed differences were assigned to the incorporation of immature organic matter in the oils and fractionation along the migration pathway. The diagenetic precursor functionality (alcohol/ether or acid) was proposed based on the comparison of the relative abundances of the neutral and acidic biomarkers (hopanoids, isoprenoids, alkyl-steranes, monoaromatic alkyl-steroids). In the acidic fraction, 3 series of steroid-alkanoic acids and monoaromatic steroid-alkanoic acids (steroid-methanoic, ethanoic and propanoic acids and monoaromatic steroid-methanoic, ethanoic and propanoic acids) were detected, while in the neutral fraction only 2 series of each corresponding class could be observed (methyl and ethyl-steranes and monoaromatic methyl and ethyl-steroids). These carbon shifts suggest that decarboxylation is an important process in the formation of the alkyrsteranes and monoaromatic alkyl-steroids, and we infer that carboxylic acids are the diagenetic precursors of these classes of compounds. When alcohol or ether are the diagenetic precursors (isoprenoids and hopanoids), no significant differences in the molecular distributions between neutral and acidic fractions were observed. (C) 2000 Elsevier B.V. Ltd. All rights reserved.