Nuno Ratola
University of Porto
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Featured researches published by Nuno Ratola.
Environmental Pollution | 2012
Askin Birgul; Athanasios Katsoyiannis; Rosalinda Gioia; John D. Crosse; Mark Earnshaw; Nuno Ratola; Kevin C. Jones; Andrew J. Sweetman
The occurrence of PBDEs has been studied in the atmosphere of four sites in the United Kingdom over a period of ten years. The concentrations have exhibited a sharp decrease after 2001-2003. This is evident in the urban sites of Manchester and London and at the semi-rural site of Hazelrigg. The average ΣPBDE half-lives for these three sites were 3.4, 2.0 and 3.5 years respectively. ΣPBDEs concentrations in the UK (in 2010 ΣPBDEs < 10 pg m(-3)) are among the lowest reported in literature. Comparison of concentrations to estimated emissions and employment of PBDE profiles suggest that PBDEs in the UK atmosphere originate from primary emissions from products that contain mainly the penta-BDE technical mixture. The detection of BDE-183 in the majority of samples hints that octa-bromodiphenylether has also been used extensively in the UK, however to a smaller extent than the penta- product.
Talanta | 2009
Nuno Ratola; Silvia Lacorte; Damià Barceló; Arminda Alves
Two different extraction strategies (microwave-assisted extraction (MAE) and ultrasonic extraction (USE)) were tested in the extraction of the 16 US Environmental Protection Agency (EPA) polycyclic aromatic hydrocarbons (PAHs) from pine trees. Extraction of needles and bark from two pine species common in the Iberian Peninsula (Pinus pinaster Ait. and Pinus pinea L.) was optimized using two amounts of sample (1g and 5 g) and two PAHs spiking levels (20 ng/g and 100 ng/g). In all cases, the clean-up procedure following extraction consisted in solid-phase extraction (SPE) with alumina cartridges. Quantification was done by gas chromatography (GC) with mass spectrometry (MS), using five deuterated PAH surrogate standards as internal standards. Limits of detection were globally below 0.2 ng/g. The method was robust for the matrices studied regardless of the extraction procedures. Recovery values between 70 and 130% were reached in most cases, except for high molecular weight PAHs (indeno[1,2,3-cd]pyrene, dibenzo[a,h]anthracene and benzo[ghi]perylene). A field study with naturally contaminated samples from eight sites (four in Portugal and four in Catalonia, Spain) showed that needles are more suitable biomonitors for PAHs, yielding concentrations from 2 to 17 times higher than those found in bark. The levels varied according to the sampling site, with the sum of the individual PAH concentrations between 213 and 1773 ng/g (dry weight). Phenanthrene was the most abundant PAH, followed by fluoranthene, naphthalene and pyrene.
Analytica Chimica Acta | 2008
Nuno Ratola; Arminda Alves; Nicolas Kalogerakis; Elefteria Psillakis
A new, fast and simple cleanup procedure, based on hollow-fibre liquid-phase microextraction (HF-LPME) is described here, used for the determination of 13 polycyclic aromatic hydrocarbons (PAHs) in complex pine needle samples. Initially, pine needle samples were sonicated in a 20 mL aqueous solution having a 20% (v:v) acetone content and 5 mL of the sonicated liquid extract was then used for the HF-LPME cleanup step. Different experimental parameters (namely: type of organic solvent used as acceptor phase, effect and type of co-solvent, salt addition, sample agitation and sampling time) were controlled and optimized based on the response of GC-MS instrument under the SIM mode. Under the optimized experimental conditions found the typical chromatograms obtained revealed that despite the very complex matrix of pine needles the HF-LPME cleanup step greatly reduced if not eliminated the presence of interferents, resulting in chromatograms which contained very cleanly separated and readily evaluable PAH peaks. In addition, the proposed method was found to be linear in the concentration 10-2000 ngg(-1) for most target analytes and the limits of detection for a S/N=3 ranged between 0.01 and 0.95 ngg(-1) (dry weight). Furthermore, the repeatability and reproducibility were also found good. Finally, the proposed method was applied for the analysis of real pine needle samples taken for different parts of the island of Crete.
Chemosphere | 2010
Nuno Ratola; José Manuel Amigo; Arminda Alves
The importance of the annual and seasonal trends associated to the polycyclic aromatic hydrocarbons (PAHs) biomonitoring by pine needles are studied with a comprehensive use of univariate and multivariate analysis tools. For this purpose, four pine needle sampling campaigns (winter, spring, summer and autumn 2007) were carried out in 29 sites from Portugal. Needles from Pinus pinaster Ait. and Pinus pinea L. trees were collected from all year-classes available in each tree, corresponding to the different shoots of needles coming out every spring and the results of both species were treated separately. Annual trends of polycyclic aromatic hydrocarbons (PAHs) contamination indicate a general increase from the least to the most exposed year-classes, for all seasons. The mean values for the sum of 16PAHs ranged from 71 ± 33 ngg(-1) (dry weight - dw) for new year (2007) needles in the summer to 514 ± 317 ngg(-1) (dw) for 2-year needles (2005) in the spring for P. pinea, and between 90 ± 50 ngg(-1) (dw) for new year (2007) needles in the summer and 1212 ± 436 ngg(-1) (dw) for 3-year needles (2004) in summer for P. pinaster. The seasonal evolution shows the highest concentrations in the winter, then declining to the lowest levels in the summer and rising again from summer to autumn. Principal component analysis confirmed differences between seasons and needle year-classes, more visible for P. pinea samples. The cooler seasons have more affinity towards the lighter more abundant PAHs, as do the older needles. Differences between both pine species are also evident.
Journal of Environmental Management | 2015
Vera Homem; José Machado da Silva; Nuno Ratola; Lúcia Silveira Santos; Arminda Alves
Synthetic musks have been used for a long time in personal care and household products. In recent years, this continuous input has increased considerably, to the point that they were recognized as emerging pollutants by the scientific community, due to their persistence in the environment, and hazardous potential to ecosystems even at low concentrations. The number of studies in literature describing their worldwide presence in several environmental matrices is growing, and many of them indicate that the techniques employed for their safe removal tend to be ineffective. This is the case of conventional activated sludge treatment plants (WWTPs), where considerable loads of synthetic musks enter mainly through domestic sewage. This review paper compiles and discusses the occurrence of these compounds in the sewage, effluents and sludge, main concentration levels and phase distributions, as well as the efficiency of the different methodologies of removal applied in these treatment facilities. To the present day, it has been demonstrated that WWTPs lack the ability to remove musks completely. This shows a clear need to develop new effective and cost-efficient remediation approaches and foresees potential for further improvements in this field.
Chemosphere | 2011
Nuno Ratola; Arminda Alves; Lúcia Silveira Santos; Silvia Lacorte
UNLABELLED Eight polybrominated diphenyl ethers (PBDEs) were determined in pine needles of three species (Pinus halepensis, Pinus pinea and Pinus nigra) collected in the NE Spain in an attempt to use this matrix for the biomonitoring of airborne PBDEs. The method used was based in ultrasonic extraction followed by alumina and Florisil clean-up and determination by gas chromatography coupled to mass spectrometry in negative chemical ionization. Recoveries were between 99% and 138%, limits of detection between 0.011 and 0.070 ng g(-1)-dw (0.232 ng g(-1)-dw for BDE 209) and repeatability lower than 13%. PBDE levels ranged between 0.027 ng g(-1)-dw and 13.04 ng g(-1)-dw, with predominance of BDE 209, followed by BDEs 47. P. halepensis was the species with the highest PBDE levels and P. nigra, the least, according to their widespread and remote distribution, respectively. The presence of PBDEs in pine needles was attributed to the release of in-use PBDEs, transport through atmosphere and adsorption upon lipid rich pine needles. Given the easy collection of pine needles, its ample distribution and its potential to accumulate airborne contaminants, this matrix is proposed as passive bio-sampler to be used in PBDE monitoring programs. CAPSULE Pine needles can be used to biomonitor airborne PBDEs.
Journal of Environmental Science and Health Part B-pesticides Food Contaminants and Agricultural Wastes | 2006
Paulo Herbert; Maria João Cabrita; Nuno Ratola; Olga Laureano; Arminda Alves
The concentration of biogenic amines and free amino acids was studied in 102 Portuguese wines and 18 musts from Alentejo demarcated (D.O.C.) regions. Most wines were commercial, except for 38 monovarietals obtained by micro vinification. Musts from the varieties used to produce the latter wines were also studied. Both biogenic amines and free amino acids were analyzed by HPLC using fluorescence detection for their o-phthalaldehyde/fluorenylmethyl chloroformate (OPA/FMOC) derivatives. The most significant amines (average 10.8 mg/L for histamine+tyramine in red, and 7.4 mg/L for white wines) were found to be present at low levels and, although no important relationship between each individual biogenic amine could be obtained, the total amine content depends significantly on the assimilable amino acid content in wine.
Science of The Total Environment | 2014
Nuno Ratola; Vera Homem; José Machado da Silva; Rita Araújo; José Manuel Amigo; Lúcia Silveira Santos; Arminda Alves
Vegetation is a useful matrix for the quantification of atmospheric pollutants such as semi-volatile organic compounds (SVOCs). In particular, pine needles stand out as effective biomonitors due to the excellent uptake properties of their waxy layer. Having previously validated an original and reliable method to analyse pesticides in pine needles, our work team set the objective of this study to determine the levels of 18 pesticides in Pinus pinea needles collected in 12 different sampling sites in Portugal. These compounds were selected among a total of 70 pesticides by previous chemical scoring, developed to assess their probability to occur in the atmosphere. The risk of exposure was evaluated by the binomial chemical score/frequency of occurrence in the analysed samples. Levels and trends of the chemical families and target of the pesticides were obtained regarding the type of land occupation of the selected sites, including the use of advanced statistics (principal component analysis, PCA). Finally, some correlations with several characteristics of the sampling sites (population, energy consumption, meteorology, etc.) were also investigated.
Environmental Technology | 2011
Sérgio Sousa; Pedro Jiménez-Guerrero; Antonio José Ortiz Ruiz; Nuno Ratola; Arminda Alves
Pesticides have been responsible for strong environmental impacts, mainly due to their persistence in the environment. Removal technologies are usually combined, because degradation of organic matter is needed prior to a tertiary treatment to guarantee pesticides elimination to levels below legal limits (normally 0.1 µg L−1). Pine bark was studied as an alternative to activated carbon, for organochlorine pesticides removal. A combination of technologies based on biodegradation with activated sludge followed by pine bark adsorption treatment was used for lindane (LIN) and heptachlor (HEP) removal from contaminated waters. Pesticides were quantified throughout the process by GC‐ECD preceded by solid‐phase microextraction (SPME). An experimental set‐up was maintained for 4 months, by feeding a standard solution with pesticides concentration of 1 µg L−1 each and known organic matter (Chemical Oxygen Demand, COD, ∼563 mg O2 L−1) on a daily basis. COD suffered a reduction of about 81% in the biological step and no increase was detected in the subsequent adsorption treatment. Overall removal efficiency was 76.6% and above 77.7% for LIN and HEP, respectively.
Analytica Chimica Acta | 2015
José Machado da Silva; Nuno Ratola; Sara Ramos; Vera Homem; Lúcia Silveira Santos; Arminda Alves
Vegetation (and pine needles in particular) has been widely used as an alternative to other conventional sampling devices to assess the atmospheric presence of semi-volatile organic contaminants (SVOCs). While most analytical procedures developed focus only on one or two chemical classes, this this work intends to establish a multi-component protocol to quantify brominated flame-retardants (BFRs), polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polynuclear aromatic hydrocarbons (PAHs) and one class of contaminant of emerging concern, the synthetic musks fragrances (SMCs). Pine needles extracts were obtained by ultrasonic solvents extraction (USE), and different cleanup approaches using solid-phase extraction (SPE) employing combinations of sorbents and solvents as well as gel permeation chromatography (GPC) were tested. SPE with alumina followed by GCP yielded the best results, with average recoveries over 80%. The application of the method under field conditions was proven by the analysis of naturally contaminated samples from 3 sites of different potential exposure (remote, rural and urban). The total detected concentrations ranged from 0.45 to 0.87 ng g(-1) dry weight (dw) for BFRs, 0.35 to 1.01 ng g(-1) (dw) for PCBs, 0.36 to 12.2 ng g(-1) (dw) for HCB, 245.7 to 967.8 ng g(-1) (dw) for PAHs and 20.7 to 277.5 ng g(-1) (dw) for SMCs. This methodology is a viable approach for the simultaneous analysis of five different classes of atmospheric pollutants employing less analytical efforts. Moreover, to the authors best knowledge, this is also the first time vegetation is employed in the detection of SMCs.