Gisele O. da Rocha

Quantification and source identification of atmospheric particulate polycyclic aromatic hydrocarbons and their dry deposition fluxes at three sites in Salvador Basin, Brazil, impacted by mobile and stationary sources

The present work has aimed to determine the 16 US EPA priority PAH atmospheric particulate matter levels present in three sites around Salvador, Bahia: (i) Lapa bus station, strongly impacted by heavy-duty diesel vehicles; (ii) Aratu harbor, impacted by an intense movement of goods, and (iii) Bananeira village on Mare Island, a non vehicle-influenced site with activities such as handcraft work and fisheries. Results indicated that BbF (0.130-6.85 ng m-3) is the PAH with highest concentration in samples from Aratu harbor and Bananeira and CRY (0.075-6.85 ng m-3) presented higher concentrations at Lapa station. PAH sources from studied sites were mainly of anthropogenic origin such as gasoline-fueled light-duty vehicles and diesel-fueled heavy-duty vehicles, discharges in the port, diesel burning from ships, dust ressuspension, indoor soot from cooking, and coal and wood combustion for energy production.

A simple, comprehensive, and miniaturized solvent extraction method for determination of particulate-phase polycyclic aromatic compounds in air.

The method allowed simultaneous characterization of PAHs, nitro-PAHs and quinones in atmospheric particulate matter. This method employs a miniaturized micro-extraction step that uses 500 μL of an acetonitrile-dichloromethane mix and instrumental analysis by means of a high-resolution GC-MS. The method was validated using the SRM1649b NIST standard reference material as well as deuterated internal standards. The results are in good agreement with the certified values and show recoveries between 75% and 145%. Limit of detection (LOD) values for PAHs were found to be between 0.5 pg (benzo[a]pyrene) to 2.1 pg (dibenzo[a,h]anthracene), for nitro-PAHs ranged between 3.2 pg (1-nitrobenzo[e]pyrene) and 22.2 pg (3-nitrophenanthrene), and for quinones ranged between 11.5 pg (1,4-naphthoquinone) and 458 pg (9,10-phenanthraquinone). The validated method was applied to real PM10 samples collected on quartz fiber filters. Concentrations in the PM10 samples ranged from 0.06 to 15 ng m(-3) for PAHs, from<LOD to 69.4 ng m(-3) for nitro-PAHs, and from 0.27 to 115 ng m(-3) for quinones. This procedure was found to be precise, accurate and suitable to be employed for determination of polycyclic aromatic compounds in airborne particles from both polluted and non-polluted atmospheres.

A simple and sensitive UFLC-fluorescence method for endocrine disrupters determination in marine waters.

The present study proposes a fast and simple analytical methodology employing C18 SPE cartridges (for preconcentration and clean-up), and a ultra-fast liquid chromatography coupled to fluorescence detector (UFLC-FLD) for determination of the following endocrine disrupters (ED): bisphenol A (BPA), 4-n-nonylphenol (4NNP), 4-n-octylphenol (4NOP), 4-t-octylphenol (4TOP), estriol (E3), estrone (E1), 17β-estradiol (E2) and 17α-ethynylestradiol (EE2) in seawater. The proposed method was developed, optimized and validated. Separation was done by a total running time of 10 min in a Shim-pack XR-ODS C-18 (2.0 mm ID × 50 mm) chromatographic column, mobile phases were acetonitrile/ultra-pure water under gradient programming; eluent flow rate at 0.120 mL min(-1); column temperature set at 60 °C; emission wavelength of 306 nm and excitation wavelength of 280 nm. The method was validated through assessment of the following parameters: linear range, linearity, selectiveness, precision, recovery test, limit of detection (LOD), and limit of quantification (LOQ). Recoveries ranged from 91% (for EE2) to 104% (for 4NNP) and also was found a suitable repeatability (RSD <4.5%) for all considered compounds. LOD and LOQ ranged from 2.0 ng L(-1) (EE2) to 23 ng L(-1) (E1) and 9.3 ng L(-1) (EE2) to 96 ng L(-1) (E1), respectively. The analytical method using SPE UFLC-FLD was applied to seawater samples collected from Todos os Santos Bay (BTS), Brazil to determine the concentration of eight ED.

A comprehensive and suitable method for determining major ions from atmospheric particulate matter matrices

The present study proposes an analytical methodology that employs ion chromatography-conductivity detection for simultaneous quantification of inorganic (F(-), Cl(-), NO(3)(-), SO(4)(2-), and PO(3)(-)), monocarboxylate (HCOO(-), CH(3)COO(-), propionate, n-butyrate, lactate, and pyruvate), dicarboxylate (oxalate and succinate), and tricarboxylate anions (citrate), as well as crustal cations (Li(+), Na(+), K(+), NH(4)(+), Ca(2+), Mg(2+)) at low pgm(-3) range in airborne particle samples in one single run. The optimized conditions for anions were as follows: 0.6 mmol L(-1) KOH for 0-14 min, 0.6-15 mmol L(-1) KOH 14-20 min, 15-38 mmol L(-1) KOH during 20-32 min and finally returned to 0.6 mmol L(-1) for a period of 3 min, thereafter the eluent flow rate was 0.38 mL min(-1). Similarly, for cations, isocratic elution was adjusted to 0.36 mL min(-1) at 17.5 mmol L(-1) H(2)SO(4). LOD ranged 3.0-130 pgm(-3) and LOQ was within 10-400 pgm(-3) (Li(+) and PO(4)(3-), respectively) as well as recoveries ranged 89% (Ca(2+)) to 120% (Li(+)). Major ions were successfully determined in real PM1 and PM2.5 samples. The method used here was found to be a comprehensive, simple, cheap and reliable procedure for studying ions in particulate matter (PM) samples even those from remote areas or near ecosystem natural conditions.

Multivariate optimization of a GC–MS method for determination of sixteen priority polycyclic aromatic hydrocarbons in environmental samples

This paper describes the development and optimization, by using multivariate analysis, of a GC-MS-SIM method for evaluation of the 16 polyaromatic hydrocarbons considered as priority pollutants in atmospheric particulate material by the US EPA. In order to assure an adequate separation in the shortest analysis time, a multivariate design was used to set the conditions of the oven temperature program. The optimization process was carried out using factorial fractional design and Box-Behnken design. The following factors were evaluated: initial temperature, temperature rate #1, intermediary temperature, temperature rate #2, and final temperature. The optimized conditions were set at: 70 degrees C (2 min) --> 200 degrees C (30 degrees C/min, 5 min) --> 300 degrees C (5 degrees C/min, 1.67 min). Moreover, we have also optimized the injector temperature as 310 degrees C and sampling time as 0.8 min. The total analysis time was 33 min. Validation of GC-MS-SIM yielded satisfactory results for repetitivity of the detector response and retention times, and linearity of calibration curves. LOD were established as 0.13-0.34 ng/mL (peak area) and 0.18-0.72 ng/mL (peak height). The method has been shown to be appropriate for the analysis of samples of atmospheric particulate material and/or other environmental matrices.

A liquid chromatographic method optimization for the assessment of low and high molar mass carbonyl compounds in wines

Carbonyl compounds (CC) play an important role in beverage aroma since they may affect flavor of wines, brandies, and beers, among others. For this reason, it is necessary to identify and quantify CC through adequate analytical techniques. This study is a proposal of both developing and optimization of a new analytical methodology that allows investigate C(1)-C(8 )CC in wines simultaneously by quantifying even those ones that are predominantly present in the adduct form hydroxylalkylsulfonic acids (HASA). The HASA dissociation is undertaken by specific alkaline media (pH 11). The developed methodology employed the LC with UV/VIS detection (lambda = 365 nm) technique under gradient elution in the way to reach both free-CC and bound-CC quantification. Results showed that binary gradient system using eluent A (MeOH/ACN/H(2)O 74.5:0.5:25% v/v/v) and eluent B (MeOH) reached the best separation condition of both lower and higher molecular mass CC. This proposed method allowed simultaneous quantification of formaldehyde, acetaldehyde, propanone, furfuraldehyde, butyraldehyde, benzaldehyde, hexanaldehyde, 2-ethyl-hexanaldehyde, E-pent-2-en-1-al, and cyclohexanone--all of them were found in white wine (Moscato Canelli) and red wine (Shiraz) produced in the São Francisco Valley, in the Northeastern Region of Brazil--although this optimized method may probably be suitable for quantification of propionaldehyde, isobutyraldehyde, heptanaldehyde, octanaldehyde, benzaldehyde, and E-hex-2-en-1-al as well. We could not prove if this method is also able to determine the latter CC group since we have not found these substances present in detectable levels in our real samples considered in this study.

Particle-associated polycyclic aromatic hydrocarbons and their dry deposition fluxes from a bus-station in the Rio de Janeiro metropolitan area, Brazil

Total particulate matter and PM10 samples were collected from August 2006 to February 2007 in Mayor Jose Carlos Lacerda bus station. 16 priority PAHs compounds emitted by heavy-duty vehicles on typical conditions of operation were analyzed by using GC/MS. ΣPAH accounted for 0.0018% of the TSP mass and 0.0012% of the PM10 mass. Total PAH contents on the particle phase were 3.57 ng m-3 and 2.59 ng m-3 for TSP and PM10, respectively. Contributions of carcinogenic USEPA priority PAHs (B[a]An, B[b]F, B[k]F, B[a]Py, IPy and DB[ah]A) were 1.86 ng m-3 (52% of total PAHs) and 1.40 ng m-3 (54% of total PAHs), for TSP and PM10 samples, respectively. Diagnostic ratios and multivariate statistical analysis were, in general, similar to those reported for soil dust except for the Flt/Flt+Py) ratio, 0.34, compatible with diesel emissions. Dry deposition fluxes were in the range of 0.022-0.603 and 0.016-0.436 μg m-2 day-1 for compounds in TSP and PM10, respectively.

Seasonal distribution of airborne trace elements and water-soluble ions in São Paulo Megacity, Brazil

This study deals with the seasonal distribution of Al, Ca, Cu, Fe, K, Mg, Na, Pb and Zn and water soluble ions (Cl-, PO43-, NO3-, SO42-, HCOO-, CH3COO-, oxalate, succinate, Na+, NH4+, K+, Mg2+ and Ca2+) found in PM10 samples (particulate matter less than 10 mm in diameter) Sao Paulo City, Brazil, (April 2003-May 2004). Higher atmospheric levels were found for SO42-, NO3-, Cl- and PO43- while the main organic anions were oxalate and formate. Atmospheric levels for elements were: Fe > Al > Ca > K > Na > Mg > Zn > Cu > Pb. Some sources were predominant for some species: (i) fuel burning and/or biomass burning (NO3-, HCOO-, C2O42-, K+, Mg2+, Ca2+, Fe, Pb, Zn, Al, Ca, K and Mg), (ii) gas-to-particle conversion (SO42- and NH4+) and (iii) sea salt spray (Cl-, Na+ and Na).

Influence of sources and meteorology on surface concentrations of gases and aerosols in a coastal industrial complex

Industrial emissions are a notorious source of atmospheric pollution in the Cubatao industrial park of Southern Brazil, where dispersion is restricted by surrounding mountain ranges. It is shown here that road transport is also a large source of gases and aerosols, which can dominate pollutant concentrations at ground level, depending on meteorological conditions. SO2 was released mainly by industry, while road transport was a major source of NOx. Rapid removal of NO2 and SO2 was attributed to fast gas phase and heterogeneous reactions, respectively. Average PM10 concentrations increased by an order of magnitude during sea breeze fumigation, and high particulate pollution events were associated with vehicular activity. It is demonstrated that fast-response portable instrumentation can provide a useful alternative to measurements at fixed network sites for spatial (horizontal and vertical) mapping of atmospheric pollutants.

Pesticides in fine airborne particles: from a green analysis method to atmospheric characterization and risk assessment

The intensive use of pesticides such as herbicides, insecticides, fungicides and acaricides has been lead to ubiquitous contamination, being present not only in soils, water bodies and/or crops, but also in the atmosphere. Considering the massive amount of pesticides employed globally, together to their persistence, this may be an important concern regarding air quality and human health worldwide. In the present study we developed a green sensitive sample preparation method for determination of nine organophosphates, two pyrethroids, one carbamate, and one strobirulin in PM2.5 collected in a tropical coastal area in the Southern Hemisphere for the first time. Extraction of PM2.5 sample masses, as low as 206 µg, were performed in a miniaturized device using 500 μL of a mixture containing 18% acetonitrile in dichloromethane followed by sonication for 23 minutes and injection into GC-MS. A total of 12 pesticides were identified and quantified successfully, among them, eight banned pesticides. A risk assessment exposure and cancer risk for possible carcinogenic pesticides (bifenthrin, malathion, parathion and permethrin) were performed for exposure of adults, children and infants. Hazard Quotient and cumulative exposure for organophosphate and pyrethroid pesticides were less than 1, showing that cumulative risk is within acceptable range.