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Gómara B, Fernández M.A, González M.-J, Ramos L.
Journal of Separation Science, vol. 29, nº 1, pags. 123 - 130 (2006)
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The different parameters affecting the ionisation and fragmentation of selected polychlorinated biphenyls (PCBs) in an IT detector working in the MS/MS mode, ITD(MS/MS), have been optimised for maximum selectivity and sensibility. The low LODs (in the range 0.03-0.3 μg/L), the satisfactory repeatability (RSDs in general below 11\%) and reproducibility (RSDs below 17\%) obtained when analysing standard solutions ensured proper determination of the PCBs studied at the concentrations typically found in food samples. Foodstuffs naturally contaminated with varying levels of PCBs have been analysed using the optimised GC-ITD(MS/MS) method. The results obtained compared favourably with those found using more conventional detectors, such as (micro-)electron capture detection (for ortho-PCBs) and high-resolution MS (for non-ortho-PCBs), as well as with the consensus PCB levels established for these particular samples via an international interlaboratory exercise. The relative merits of these three detectors have been discussed. © 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinham.
Gómara B, González M.-J
Chemosphere, vol. 63, nº 4, pags. 662 - 669 (2006)
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The content of 30 polychlorinated biphenyls (PCBs) and the enantiomeric fractions of 10 chiral PCBs were determined in 17 infertile eggs from three different predatory bird species collected in Doñana National Park (DNP, Spain) in the period 1999-2000. The highest PCB concentration was found in eggs from red kites (0.52-110 μg/g on a fresh weight basis, f.w.) followed by buzzard (0.08-13 μg/g f.w.) and booted eagle (0.10-1.5 μg/g f.w.). Seventy-five percent of the red kite eggs had PCB levels above 4.7 μg/g f.w., which is associated in the literature with reproductive failure. This could be related to the fact that red kite populations have decreased by more than 50\% in the last five years in DNP. PCBs # 138, 153, and 180 were the most abundant in all cases. This is the first time that atropisomers of 10 chiral PCBs (PCBs # 45, 84, 91, 95, 132, 135, 136, 149, 174, and 176) in predatory bird eggs have been performed. The enantiomeric fractions (EFs) for most PCBs investigated were non-racemic (EF ≠ 0.5), ranging from 0.05 to 0.95. The results suggested that predatory birds, mainly red kite species, are highly polluted by PCBs, and PCBs # 95, 132, 135, 136, and 174 strongly deviate from the racemic-mixture values. © 2005 Elsevier Ltd. All rights reserved.
Gómara B, Herrero L, González M.-J
Environmental Science and Technology, vol. 40, nº 24, pags. 7541 - 7547 (2006)
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Concentrations of 15 BDEs flame retardants have been determined in a large variety of food samples purchased in different markets across Spain. This is the first time that BDEs 184, 191, 196, and 197; impurities from BDEs formulations; and/or degradation products of BDE 209, have been detected in foodstuffs. Values ranged from <0.01 to 2482 pg/g fresh weight. The highest total BDE concentrations were found in fish samples (median of 189, range of 24-880 pg/g f.w.), followed by oils (median of 119, range of 14.8-2958 pg/g f.w.), meats (median of 75.9, range of 6.82-2518 pg/g f.w.), shellfish (median of 75.7, range of 3.29-677 pg/g f.w.), eggs (median of 73.5, range of 12.8-557 pg/g f.w.), and dairy products (median of 66.1, range of 3.24-1588 pg/g f.w.). The total BDE values found in this study are consistent with research reported elsewhere. They are in the same range as those recently reported by other European and Asian studies and lower than those conducted in the U.S. BDE 47 was the predominant congener in fish, shellfish, dairy products (except butter), and meats, while BDE 209 was the predominant in oil and egg samples. The most remarkable findings in this study were the large contribution of the highest brominated BDEs (hepta- to deca-BDE), and principally BDE 209, to the total BDE concentration found in Spanish foods, except fish and shellfish, and the presence of BDE 184, 191, 196, and 197 in many of the samples. The calculated intake of 38.5 ng/day of BDEs was comparable to intake assessment from other UE countries. © 2006 American Chemical Society.
Gómara B, Bordajandi L.R, Fernández M.A, Herrero L, Abad E, Ábalos M, Rivera J, González M.-J
Journal of Agricultural and Food Chemistry, vol. 53, nº 21, pags. 8406 - 8413 (2005)
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The polychlorinated dibenzo-p-dioxin (PCDD), dibenzofuran (PCDF), and polychlorinated biphenyl (PCB) contents of 123 Spanish commercial salmon, tuna fish, sardine, oyster, mussel, and clam samples from 1995 to 2003 were investigated. A significant decrease of dioxin and non-ortho PCB concentrations in the studied species was found over the years. The decrease was greater in the case of dioxins than in that of non-ortho PCBs, especially during the early years of the study. PCB and PCDD/F concentrations in the years 2001-2003 were comparable to those reported in the literature for similar species collected after 1999. Mean PCB concentrations ranged from 3.46 ng/g of fresh weight (fw) in clams to 100 ng/g of fw in tuna fish. PCDD/F mean current levels ranged from 0.62 pg/g of fw in clams to 2.89 pg/g of fw in oysters. Toxic equivalent quantities (WHO-TEQ) ranged from 0.05 pg of WHO-TEQPCDD/Fs/g of fw in clams to 0.5 pg of WHO-TEQPCDD/Fs/g of fw in salmon (in the upper bound determination levels). When coplanar PCBs were included, the WHO-TEQ PCDD/Fs+cop PCBs values increased by a range of 1.7 times in oysters to 14.1 times in tuna fish. The decrease in dioxin concentrations suggests that efforts to control dioxin emissions and to reduce human exposure through foodstuffs are succeeding. The high contribution of PCBs to total WHO-TEQs in the fish and shellfish species investigated suggests that it is important to determine PCBs in foodstuffs, and especially in fish products, and they should be included in further research and future legislation. © 2005 American Chemical Society.
Gómara B, Ramos L., Gangoso L, Donázar J.A, González M.-J
Chemosphere, vol. 55, nº 4, pags. 577 - 583 (2004)
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Concentrations of 23 polychlorinated biphenyls (PCBs), p,p′-DDT and two of its metabolites, p,p′-DDE and p,p′-TDE have been measured in serum samples of up to 1 ml of Egyptian Vulture (Neophron percnopterus) gathered from five populations in Spain. ∑PCB concentrations were found to be in the range 3.2-97 ng/ml, while those of ∑DDTs ranged from 0.93 to 38 ng/ml. p,p′-DDT/p,p′-DDE ratios higher than one were only found in the Segovia population, which could be an indication of recent use of p,p′-DDT in the area. In all cases, PCB profiles were dominated by congeners 52, 132+105, 138, 153 and 180. However, some differences among the five populations studied became evident when their profiles were compared with those of technical PCB mixtures by principal components analysis. The DDT and PCB levels detected in the serums analysed were lower than those previously reported for similar avian species and those reported to have deleterious effects on survival or reproduction of birds. © 2003 Elsevier Ltd. All rights reserved.
Fernández M.A, Gómara B, Bordajandi L.R, Herrero L, Abad E, Ábalos M, Rivera J, González M.-J
Food Additives and Contaminants, vol. 21, nº 10, pags. 983 - 991 (2004)
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Congener-specific analyses of seventeen 2,3,7,8-substituted PCDD/Fs, three non-ortho and 8 mono-ortho dioxin-like polychlorinated biphenyls (PCBs) were performed on 258 Spanish foodstuff samples, mainly of animal origin, for 2000-03. Daily dietary intakes of PCDD/Fs and PCBs, expressed as toxic equivalents (WHO-TEQs), were estimated by combining food consumption data from the Spanish National Institute Statistics survey and concentration levels measured in individual samples, using upper bound determination values (not detectable = limit of detection). The calculated dietary intake of PCDD/Fs for a person weighing 70 kg was 1.35 ± 0.11 pg WHO-TEQs kg-1 bw day-1, and 3.22 ± 0.75 pg WHO-TEQs kg-1 bw day-1 if diox-in-like PCBs (non- and mono-ortho PCBs) were included, showing the importance of their inclusion in monitoring studies. Both values were within the range of tolerable daily intake (TDI) proposed by the WHO (1-4 pg WHO-TEQs kg-1 bw day-1). The current levels are lower than earlier intakes estimates conducted in Spain. Meat and meat products accounted for more than 35\% of the intake, followed by milk and milk products (29\%), vegetables oils (19\%), fish and seafood (11\%) and eggs (4\%). Dioxin-like PCBs are an important component in the total WHO-TEQs in foodstuffs. This is particularly true for the fish food group, where the total WHO-TEQs is dominated by dioxin-like PCBs (up to 80\% of WHO-TEQs in some cases).
Gómez G, Baos R, Gómara B, Jiménez B., Benito V, Montoro R, Hiraldo F., González M.-J
Archives of Environmental Contamination and Toxicology, vol. 47, nº 4, pags. 521 - 529 (2004)
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This article presents the impact on waterbirds in Doñana National Park (Spain) of an accidental release of 5 million m3 acid waste produced by the processing of pyrite ore. Heavy metals (zinc, copper, cadmium, and lead) and arsenic were measured in several soft tissues (liver, kidney, and muscle) taken from 14 waterfowl species collected between April 1998 and May 2000. The main source of copper and zinc found in the waterfowl species examined was the spill waste, whereas cadmium, lead, and arsenic could also came from other sources. Kidney was the primary organ for cadmium and lead accumulation, whereas liver accumulated the most zinc and copper. Arsenic was concentrated in both muscle and liver tissue. The degree of contamination of the area where the birds lived, their age, their sex their size, and the time since the spill were found to have less influence than species and trophic level on the accumulation of metal in organs and tissues. Four species (Anser anser, Ciconia ciconia, Larus ridibundus, and Porphyrio porphyrio) were found to have the highest levels of the 5 elements.
Gómara B, Ramos L., González M.-J
Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences, vol. 766, nº 2, pags. 279 - 287 (2002)
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An new method for the determination of polychlorinated biphenyls (PCBs) in serum samples of up to 1 ml has been developed. The procedure consisted in the solid-phase extraction (SPE) of the analytes on an Oasis cartridge and the subsequent on-line elimination of the fat by directly dropping of the eluate from the SPE cartridge on a multilayer column placed below the cartridge. This configuration allowed minimising of the sample manipulation as well as the time, solvent and sorbent consumption (i.e. complete sample preparation can be accomplished in about 1 h with only 3 ml of toluene and 300 mg of silica). The SPE plus clean-up method developed showed a satisfactory performance for the analysis of PCBs in rat serum samples providing similar recoveries (i.e. range 73-128\% for most of the congeners selected) at the different spiking levels investigated (1.25, 0.50 and 0.25 ng/ml). Detection limits using a microelectron capture detector were in the range 0.01-0.30 ng/ml of serum and the relative standard deviations of the complete method better than 18\% irrespective of the PCB concentration. The validated method has been applied to the evaluation for the first time of the PCB levels in serum samples of up to 1 ml from individuals of an Egyptian Vulture colony in Spain. © 2002 Elsevier Science B.V. All rights reserved.
Concejero M.A, Ramos L., Jiménez B., Gómara B, Abad E, Rivera J, González M.-J
Journal of Chromatography A, vol. 917, nº 1-2, pags. 227 - 237 (2001)
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Feasibility of several sorbents, Amoco PX-21, Carbosphere, Carbopack B and C and 2-(1-pyrenyl) ethyldimethylsilylated silica gel (PYE), for the fractionation of polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins and furans was investigated. Selection was based on their suitability for quantitative isolation of the target compounds with special attention for the most toxic mono- and non-ortho-CBs to prevent coelution with other congeners during the final determination by gas chromatography. Cost-effectiveness in terms of solvent and time consumption as well as feasibility for routine analysis and automation were considered additional merits of the methods compared. Final evaluation of the procedures providing the best results was done by comparison of the results obtained from the analysis of real-life samples. The results showed that, among the sorbents tested, Carbopack B and PYE were the most suitable for routine analysis. In particular, these sorbents allowed a more reliable determination of the toxic congeners and, consequently, of the toxic equivalents of 2,3,7,8-tetrachlorodibenzo-p-dioxin content in environmental samples. © 2001 Elsevier Science B.V.
Hernández L.M., Gómara B, Fernández M.A, Jiménez B., González M.-J, Baos R, Hiraldo F., Ferrer M, Benito V, Suñer M.A, Devesa V, Muñoz O, Montoro R
Science of the Total Environment, vol. 242, nº 1-3, pags. 293 - 308 (1999)
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The impact of the spill from the mine in Aznalcollar (Seville, Spain) on waterfowl in the Donana National Park is assessed. The concentrations of Cu, Pb, Cd, Zn and As in the liver and eggs of 16 species of waterfowl found dead in the Park between April and November 1998 were determined. The highest levels were found for Zn, followed by Cu, Pb, Cd and As. The main parameters related to the accumulation of these elements in the waterfowl studied were species and trophic level. The other variables studied - distance from the spill, days of exposure, sex, size, and age - are important, although this depends on the element studied. Zn and Cu from the spill have entered the food chain of the aquatic birds studied, but Cd, Pb and As have not. There is currently no evidence to suggest that the trace element concentrations measured have reached toxic levels. Copyright (C) 1999 Elsevier Science B.V.