Seasonal variation of polycyclic aromatic hydrocarbons concentrations in urban streams at Niterói City, RJ, Brazil.

Polycyclic aromatic hydrocarbons (PAHs) were determined in water samples collected in two streams and a lake located at Niteroi City, Rio de Janeiro State, Brazil between October 2008 and September 2009. Samples were extracted using liquid-liquid extraction and analyzed using high performance liquid chromatography with fluorescence detection. The limits of quantification were sufficiently low to accomplish PAH determination below the maximum concentration levels established by the Brazilian (50 ng/L) and USEPA legislations, with recoveries larger than 81.6%. Phenanthrene, fluoranthene, pyrene and benz[a]anthracene predominated among PAHs. Total concentrations of PAHs were well correlated with rainfall indicating a possible role of runoff to local pollution of water by PAHs and showed a seasonal variation in wet and dry seasons. Our results highlight the contribution of the widespread streams located around Guanabara Bay to the PAH burden found in its waters.

Occupational exposure to formaldehyde in an institute of morphology in Brazil: a comparison of area and personal sampling.

BACKGROUND, AIMS, AND SCOPE: Formaldehyde (FA) is a harmful chemical, which is classified as carcinogenic to humans (Group 1) by the International Agency for Research on Cancer. Solutions of FA that are used to preserve cadavers in research and education morphological institutes represent a risk to occupational health of professionals and students. During the dissection of cadavers in the anatomy laboratories, FA vapors are emitted, resulting in the exposure of students and their instructors to elevated levels of FA. The World Health Organization recommends an air quality guideline value of 0.1 mg m(-3) for exposure to FA. The limit of occupational exposure adopted by the Brazilian legislation (2.3 mg m(-3)) is markedly higher than those adopted by institutions of other countries around the world. The purpose of this study was to determine the levels of personal exposure and the area concentration of FA in the morphology department of the Federal Fluminense University, Brazil, and investigate and compare the relationship between them. METHODS: Four rooms distributed in the three floors of the Morphology Department were evaluated: the embalming laboratory, the anatomy laboratories, the corridor of the teachers' rooms, and the entrance hall. Thirty-six samples in total were collected in the second semester of 2010 and first semester of 2011. The air sampling and FA analysis were performed according to the EPA TO-11A Protocol, using a diffusive sampling device for carbonyl compounds. Personal samples were collected from monitors using a sampling device pinned on each person's lapel. The samples were analyzed using rapid resolution liquid chromatography with UV-DAD detection at 360 nm. RESULTS AND DISCUSSION: The concentrations of FA ranged from 0.20 and 0.18 mg m(-3) in the corridor between the teachers' rooms, 0.03 to 0.37 mg m(-3) in the entrance hall, 0.22 to 2.07 mg m(-3) in the anatomy laboratory, 2.21 to 2.52 mg m(-3), in the embalming room. The levels found in the corridor between the teachers' rooms and in the entrance hall were lower than in other compartments because of their large distances to the sources of FA and better ventilation. The other rooms presented higher levels of FA because of the activities carried there (embalming and dissection procedures). Even in the rooms that showed the lowest levels of FA, the values found were higher than those established by all international guideline limits, except the Brazilian legislation limit, although, the concentration level in the embalming room was even greater than the Brazilian guideline. These concentrations are 100-1,000-fold higher than those reported in an FA outdoor study. The exposure levels of monitors and students ranged from 1.89 to 4.82 mg m(-3), indicating that current practices at the Morphology Department at the university would represent a health risk. The simultaneous monitoring of area concentrations and personal exposure showed that the characteristics of classes and of cadavers' parts, the number of students in the room and even the activities of the monitors influence the FA concentrations. CONCLUSION: This study revealed that the concentration of FA was low in the ventilated areas of the Morphology Department, and that the personal exposure when the person was close to the cadavers during the dissection procedure was higher than the mean FA concentration. This should be considered in the risk assessment of FA during these activities without effective protection equipment. It is suggested that the Brazilian legislation of exposure to formaldehyde requires an urgent update considering international legislation.

Optimization and comparison of HPLC and RRLC conditions for the analysis of carbonyl-DNPH derivatives.

Analytical conditions for the analysis of 15 carbonyl-DNPH derivatives were optimized and compared by high performance liquid chromatography (HPLC) and rapid resolution liquid chromatography (RRLC). Binary, ternary and quaternary mixtures of acetonitrile, isopropanol, methanol, tetrahydrofuran and water were evaluated under RRLC conditions employing a Zorbax Eclipse Plus C18 (50 mm x 4.6 mm x 1.8 microm) column and a Zorbax Eclipse Plus C18 (50 mm x 2.1 mm x 1.8 microm) column. The optimized conditions obtained employing the two RRLC columns were compared with those obtained using a Supelcosil C18 (250 mm x 4.6 mm x 5 microm; Supelco) that is designed for HPLC separation of DNPH derivatives. Chromatograms run with a Zorbax Eclipse Plus C18 (50 mm x 2.1 mm x 1.8 microm) column and a mobile phase composed of isopropanol, methanol, tetrahydrofuran and water led to the best separation conditions considering reduced analysis time (approximately 6 min per run), solvent consumption rate (approximately 2 mL per run) and resolution of propanone, acrolein and propionaldehyde hydrazones. Quantification limits and linear ranges were adequate for direct application of EPA TO-11 conditions in all sets of RRLC and HPLC conditions. The analytical method was applied in the determination of carbonyl compounds (CCs) in Niterói City, RJ, Brazil in samples that were collected during periods of 2h. Formaldehyde (8.22-9.78 ppbv) predominated in all periods followed by acetaldehyde (1.77-3.99ppbv) and propanone (1.89-3.26 ppbv). Heavy CCs such as butyraldehyde and benzaldehyde were also detected in most samples. Total CCs varied along the studied day. The obtained results showed that RRLC can be applied to CCs determination without any change in the conditions of sample preparation of the Method EPA TO-11.

Optimization and application of methods of triacylglycerol evaluation for characterization of olive oil adulteration by soybean oil with HPLC-APCI-MS-MS.

Triacylglycerols (TAGs) are the main constituents of vegetable oils where they occur in complex mixtures with characteristic distributions. Mass spectrometry using an atmospheric pressure chemical ionization interface (APCI-MS) run in positive mode and an Ion Trap mass analyser were applied in the study of olive and soybean oils and their mixtures. Direct injections of soybean and olive oil solutions allowed the identification of ions derived from the main TAGs of both oils. This procedure showed to be a simple and powerful tool to evaluate mixtures or addition of soybean to olive oil. TAG separation was optimized by high performance liquid chromatography (HPLC) using an octadecylsilica LiChrospher column (250mm x 3mm; 5microm) and a gradient composed of acetonitrile and 2-propanol allowed the separation of the main TAGs of the studied oils. APCI vaporization temperature was optimized and best signals were obtained at 370 degrees C. Multiple reaction monitoring (MRM) employing the transition of the protonated TAG molecules ([M+H](+)) to the protonated diacylglycerol fragments ([M+H-R](+)) improved the selectivity of TAG detection and was used in quantitative studies. Different strategies were developed to evaluate oil composition following TAG analysis by MRM. The external standard calibration and standard additions methods were compared for triolein quantification but the former showed to be biased. Further quantitative studies were based on the estimates of soybean and olive oil proportions in mixtures by comparison of TAG areas found in mixtures of known and unknown composition of both oils. Good agreement with expected or labeled values was found for a commercial blend containing 15% (w/w) of olive oil in soybean oil and to a 1:1 mixture of both oils, showing the potential of this method in characterizing oil mixtures and estimating oil proportions. Olive oils of different origins were also evaluated by mass spectra data obtained after direct injections of oil solutions and principal component analysis (PCA). Argentinean olive oils were clustered in a different area of the principal components plot (PC2 xP C1) in comparison with European olive oils. The commercial blend containing 15% (w/w) of olive oil in soybean oil appeared in a completely different area of the graphic, showing the potential of this method to screen out for olive oil adulterations.

Polycyclic aromatic hydrocarbons in Tripuí River, Ouro Preto, MG, Brazil.

This paper reports the determination of 15 EPA-polycyclic aromatic hydrocarbons (PAHs) and benzo[e]pyrene in water samples collected in Tripuí River, Ouro Preto City, MG, Brazil. Samples were collected between September 2006 (dry season) and November 2006 (wet season) in the neighborhood of an aluminum smelter. Detection limits and quantification limits were sufficiently low to accomplish PAH determination below the maximum concentration levels established by the Brazilian and USEPA legislations. Recoveries from water spiked samples were always larger than 89%. Fluoranthene, pyrene, phenanthrene, chrysene and benzo[b]fluoranthene predominated in the studied samples. The concentrations of PAHs upstream the aluminum smelter were systematically lower than those found downstream indicating a possible role of the smelter in the local pollution by PAHs. Principal component analysis and cluster analysis also showed remarkable differences of the characteristics of samples collected upstream and downstream the aluminum smelter and also of samples from wet and dry seasons.

Multivariate optimization of a liquid-liquid extraction of the EPA-PAHs from natural contaminated waters prior to determination by liquid chromatography with fluorescence detection.

This paper reports the multivariate optimization of a liquid-liquid extraction procedure for the determination of 15 EPA-polycyclic aromatic hydrocarbons (PAHs) by high-performance liquid chromatography with fluorescence detection. A Doehlert design was used to find optimum conditions for the procedure through Response Surface Methodology. Three variables (total volume of hexane, number of extraction steps and duration of such steps) were elected as factors in the optimization study. A principal component analysis (PCA) was run with optimized data, resulting in four groups of PAHs, ordered according to their molecular weight. Final working conditions were established in order to achieve a more robust methodology in relation to all fifteen PAHs under study. Best results could be observed when 77 mL of hexane were divided in four consecutive extraction steps with 18 min each. These experimental conditions were applied in the analysis of a spiked river water sample, and the recoveries varied between 80.9 and 106%, with an average value of 97.1+/-6.8%. The application of the methodology to river water showed that the method has a good average precision for the studied PAHs.

Characterization of solid-phase extraction of Fe(III) by unloaded polyurethane foam as thiocyanate complex.

This work presents a detailed study about the adsorption of iron(III)-thiocyanate complexes onto unloaded polyether-type polyurethane foam (PUF). A novel strategy was employed for this purpose, utilizing the adjustment of the plug cylinder of PUF to the arm of an overhead stirrer. The system was characterized in relation to equilibrium and kinetic aspects and it was modeled by applying Langmuir and Freundlich isotherms. The results obtained showed that adsorption occurs on a monolayer and that external transport of the solute from solution to adsorbent was the rate-determining mechanism. A maximum adsorption capacity of 2.06 x 10(-4) mol Fe g(-1) was obtained under established experimental conditions (0.5 mol L(-1) SCN(-) and 0.005 mol L(-1) HCl). Sequential extraction experiments were carried out by changing PUF in time intervals previously defined (5, 20, and 40 min), and the obtained results showed that it is possible to remove around 95% of the Fe(III) in solution through five consecutive extractions of 5 min with five 200 mg PUF cylinders.

Multivariate optimization of a microwave-assisted leaching procedure using dilute acid solutions, for FAAS determination of Cu, Fe, Mn, and Zn in multivitamin/multimineral supplements.

This paper reports the development of a microwave-assisted procedure for leaching of copper, iron, manganese, and zinc from multivitamin/multimineral supplements by use of dilute acid before determination by flame atomic absorption spectrometry (FAAS). A Doehlert design was used to find optimum conditions for the procedure by use of response-surface methodology. Three variables (acid concentration in the leaching solution, irradiation time, and irradiation power) were used as factors in the optimization study for two acids, HCl and HNO(3). Final working conditions were established as a compromise between the optimum values for each analyte, taking into consideration the robustness of the procedure. The best leaching results were obtained with HNO(3) and the acid concentration, irradiation time, and irradiation power used were 0.70 mol L(-1), 15 min and 360 W, respectively. The accuracy of the optimized procedure was evaluated by comparison with a well-established closed-vessel microwave dissolution technique.

Spatial distribution of polycyclic aromatic hydrocarbons in Terminalia catappa L. (Combretaceae) bark from a selected heavy road traffic area of Rio de Janeiro City, Brazil.

The levels of 21 polycyclic aromatic hydrocarbons (PAHs) with molecular weights between 128 Da (naphthalene) and 300 Da (coronene) were determined in Terminalia catappa L. (Combretaceae) bark. Tree bark samples were collected in the campus of Oswaldo Cruz Foundation, a green area located in a very intensive traffic area of Rio de Janeiro City, Brazil and about 10 km away from the city center. Samples were submitted to ultrasonic extraction with dichloromethane and analyzed by high-resolution gas chromatography-mass spectrometry. Individual PAH levels varied from 1.23 to 327 ng/g and phenanthrene, fluoranthene and pyrene predominated in all samples. Total PAH levels ranged from 242 to 1640 ng/g with a mean of 628 ng/g. The levels of total PAHs and of total carcinogenic PAHs showed not a clear dependence with tree location and distances to the main routes of that area. No correlation was observed also with PAH levels previously found in total suspended particulate thus indicating that in this area tree bark PAH levels cannot be used to assess their atmospheric levels.

[Polycyclic aromatic hydrocarbons in industrial solid waste: a preliminary evaluation of the potential risk of environmental and human contamination in waste disposal areas]. / Hidrocarbonetos policíclicos aromáticos em resíduos sólidos industriais: uma avaliação preliminar do risco potencial de contaminação ambiental e humana em áreas de disposição de resíduos.

Proper solid waste disposal is important to avoid human and environmental contamination. The NBR 10,004 Waste Classification lists several polycyclic aromatic hydrocarbons (PAHs) and indicates that the presence of at least one PAH in a waste sample is enough to classify it as hazardous. The aim of this study was a preliminary evaluation of PAHs in solid waste samples from selected industries to obtain a preliminary overview of their potential for contamination in case of improper disposal. One or more PAHs listed in NBR 10,004 (benzo[a]anthracene, benzo[a]pyrene, benzo[b]fluoranthene, benzo[k]fluoranthene, indene[1,2,3-c,d]pyrene, chrysene, or fluoranthene) were found in all samples, thus leading to their classification as hazardous waste. Our results showed that toxicologically relevant PAHs were found in all the samples, indicating that their final disposal must be performed in appropriate areas in order to minimize human health risks and environmental contamination from waste disposal areas.

Hidrocarbonetos policíclicos aromáticos em resíduos sólidos industriais: uma avaliaçäo preliminar do risco potencial de contaminaçäo ambiental e humana em áreas de disposiçäo de resíduos / Polycyclic aromatic hydrocarbons in industrial solid waste: a preliminary evaluation of the potential risk of environmental and human contamination in waste disposal areas

A disposiçäo adequada dos resíduos sólidos é importante para evitar que os mesmos se transformem em fonte de contaminaçäo ambiental e humana. A NBR 10.004 - Classificaçäo de Resíduos - lista vários hidrocarbonetos policíclicos aromáticos (HPAs) e indica que, a presença de pelo menos um deles na massa bruta do resíduo é suficiente para classificá-lo como resíduo perigoso. O objetivo deste estudo foi verificar a presença de HPAs em amostras de resíduos sólidos provenientes de alguns segmentos industriais, para se obter uma avaliaçäo preliminar do potencial de contaminaçäo que estes resíduos podem representar, caso näo recebam destino adequado. Pelo menos um dos HPAs previstos na NBR 10.004 (benzo[a]antraceno, benzo[a]pireno, benzo[b]fluoranteno, benzo[k]fluoranteno, indeno[1,2,3-c,d]pireno, criseno ou fluoranteno) foi identificado em todos os resíduos estudados, classificando-os como perigosos. Nossos resultados indicam que todos os resíduos estudados continham HPAs de importância toxicológica, o que implica que sua disposiçäo final seja feita em locais adequados para minimizar os riscos à saúde humana e ambiental oriundos das áreas de disposiçäo de resíduos