Biomedical subjects

Eric Jover

Publications and source records attributed to Eric Jover.

11 recordsLinked to original sources

PubMed2006

Mercury speciation in the hair of pre-school children living near a chlor-alkali plant.

Exposure to mercury species was assessed in the hair of 130 Spanish children (age 4) from the general population in two areas. Both areas are exposed to different sources of mercury: a point source in Ribera d'Ebre (northeastern Spain) and a diffuse source on the island of Menorca (northwestern Mediterranean). The median MeHg values in the hair of children from Ribera d'Ebre (RE) were nearly twice (0.631 microg/g vs. 0.370 microg/g) those of children from Menorca (MC) (p < 0.05). Total Hg showed a similar trend (REmedian: 0.720 microg/g vs. MCmedian: 0.476 microg/g). Nevertheless, inorganic mercury levels were similar in the two groups of children (REmedian: 0.186 microg/g vs. MCmedian: 0.210 microg/g). Two subgroups of the Ribera d'Ebre group were defined: children living in Flix (a village near a chlor-alkali plant) (RE1) and children living on the outskirts of Flix with no clear, direct influence of the plant (RE2). The mercury concentrations in RE1 were also significantly higher than those in Menorca, but no significant differences were found between Menorca and the RE2 subgroup. We evaluated the fish consumption of RE1, RE2 and MC and found that the Menorcan children consumed significantly less fish (p < 0.05) than the other two subgroups. Children who consumed fish more than three times a week had higher MeHg concentrations (beta (SE) = 0.991 (0.279) than those who ate it less than once a week. Nevertheless, the differences in MeHg levels between children from Ribera d'Ebre and Menorca remained statistically significant after adjustment for fish intake and other variables (beta (SE) = 0.779 (0.203) for children from RE1). In conclusion, local sources other than seafood contribute significantly to MeHg content in hair in the two Ribera d'Ebre subgroups.

Chemical Industry↗

PubMed2006

Transport of organic contaminants through salinity stratified water masses. A microcosm experiment.

A salt-wedge stratified microcosm, spiked with 31 target analytes, including PCBs, organochlorine and organophosphorous pesticides, triazines, organophosphate flame retardants and caffeine (an urban wastewater molecular marker), was setup. Compound behaviour was monitored during a four week period, by sampling at six different levels of the water column, in order to understand the transport and loss processes of the different classes of chemical substances. Compound transport from one water body to the other has been positively correlated with diffusion via their molar volume. Target analytes loss has been positively correlated with evaporation via their K(H) and with degradation via their halve-lives. From these two processes, evaporation was found to be predominant using a multiparametric regression.

Diffusion↗

PubMed2006

Estrogenic and dioxin-like compounds in sediment from Zierikzee harbour identified with CALUX assay-directed fractionation combined with one and two dimensional gas chromatography analyses.

The identity of compounds responsible for estrogenic and dioxin-like activities in sediment from the harbour of the small town Zierikzee in Zeeland, The Netherlands, was investigated using a bioassay directed fractionation approach with the in vitro estrogen and dioxin responsive reporter gene assays ER- and DR-CALUX. For identification of compounds exhibiting activity in the bioassays, either one or two-dimensional GC in combination with quadrupole (MSD), ion trap (ITD) or time-of-flight mass spectrometric detection (ToF-MS) was used, depending on the biological and chemical characteristics and the complexity of the fractions. The natural estrogenic hormone 17-beta-estradiol and its metabolite estrone were identified with GC-ITD as the main contributors to the estrogenic activity. After successive rounds of fractionation, the dioxin-like activity could be explained by the presence of various polycyclic aromatic hydrocarbons identified with GC-MSD and two-dimensional comprehensive GC x GC-ToF-MS. Some estrogenic activity of a relatively non-polar nature remained unidentified.

Chromatography, Gas↗

PubMed2006

Occurrence and degradation of butyltins and wastewater marker compounds in sediments from Barcelona harbor, Spain.

Contamination of Barcelona harbor sediments was assessed by the quantitative determination of butyltins (TBT, DBT and MBT) and surfactant intermediates, namely linear alkylbenzenes (LABs) and nonylphenols (NPs), as markers of urban and industrial wastewater contamination, respectively. Degradation indexes of TBT and LABs were calculated. Tributyltin predominated in the whole area over its degradation products, ranging from 98 to 4702 ng Sn/g. These elevated concentrations reveal a persistent historical contamination and a moderate degradation (BT(deg)). Moreover, the high LAB concentrations (1.2-53.1 microg/g) compared to the relatively low NP levels (3.8-72.0 ng/g) suggest a predominance of urban over industrial wastewater inputs, although a significant correlation (r(2) = 0.82, N = 12, P = 0.001) between LABs and NPs was found. Stormwater runoff and combined sewer overflows (CSO) were likely the most possible sources for both surfactant intermediates. The high degradation index values obtained for LABs could indicate an improvement in the wastewater management reducing its recent discharge into the Barcelona harbor area.

Benzene↗

PubMed2006

Organic contaminant loads into the Western Mediterranean Sea: estimate of Ebro River inputs.

Annual input estimates for several organic contaminants from the Ebro River into the Northwestern Mediterranean Sea were carried out on the basis of monthly sampling from November 2002 to October 2003. Some organochlorine compounds (DDT and its degradation products, DDD and DDE, PCBs (9 congeners), HCB and gamma-HCH) were selected due to their reported occurrence in the river. Furthermore, some polar pesticides used in the Ebro Delta were also determined (atrazine, simazine, diazinon, fenitrothion and molinate). Concentrations ranged from 0.4 to 19.5 ng l(-1) for the organochlorine compounds (sum of particulate and dissolved phases) and from not detected (ND) to 170 ng l(-1) for the more polar pesticides, which were only found in the dissolved phase. The sum of PCB congeners (mean 8.9 ng l(-1)) showed the highest concentrations among the organochlorine compounds and atrazine (mean 82 ng l(-1)) among the polar pesticides. Based on the contaminant concentrations and on hydrological data, contaminant discharges into the sea were estimated amounting in total to 167 and 1,258 kg year(-1) of organochlorine compounds and polar pesticides, respectively. Furthermore, it was observed that PCBs, DDTs and HCB inputs were basically influenced by spate periods due to an increase in suspended particulate matter associated to runoff and sediment resuspension. Whereas for more water soluble contaminants, such as the agrochemicals, their seasonal use had a higher incidence in contaminant fluxes. Bulk chemical parameters such as SPM, DOC, POC, %OC, %ON and C/N ratio provided additional information on the organic matter sources. This provides a better understanding of the temporal variability of the contaminant concentrations.

Animals↗

PubMed2005

Twin comprehensive two-dimensional gas chromatographic system: concept and applications.

A twin GC x GC system has been designed which enables the analysis of a sample by means of two different and independent column combinations simultaneously. Both combinations are incorporated in the same oven, using the same temperature programme, and are fed using a 50:50 column-entrance-split. It is demonstrated that, employing combinations of a conventional non-polar x polar and a reversed-type polar x non-polar column set, the information content is as high, and the analytical performance is as good as when using two separate GC x GC systems. That is, there is an appreciable gain of time and a reduction of costs without any loss of quality. The general usefulness of performing, and comparing two mutually different GC x GC runs is further illustrated with FAMEs in olive oil, and pollutants in a sediment sample.

Chromatography, Gas↗

PubMed2005

Characterization of lipids in complex samples using comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry.

Most lipids are a complex mixture of classes of compounds such as fatty acids, fatty alcohols, diols, sterols and hydroxy acids. In this study, the suitability of comprehensive two-dimensional gas chromatography coupled to a time-of-light mass spectrometer is studied for lipid characterization in complex samples. With lanolin, a refined wool wax, as test sample, it is demonstrated that combined methylation plus silylation is the preferred derivatization procedure to achieve (i) high-quality GC x GC separation and (ii) easily recognizable ordered structures in lipid analysis. Optimization of the GC x GC column combination, the influence of the temperature programme on the quality of the separation, and the potential and limitations of automated TOF-MS-based identification are discussed. The combined power of a 2D separation, ordered structures and MS detection is illustrated by the identification of several minor sample constituents.

Gas Chromatography-Mass Spectrometry↗

PubMed2002

Complete characterisation of lanolin steryl esters by sub-ambient pressure gas chromatography-mass spectrometry in the electron impact and chemical ionisation modes.

Steryl esters occurring in lanolin have been characterised by sub-ambient pressure gas chromatography coupled to mass spectrometry. Electron impact and chemical ionisation modes with different reagent gases have been evaluated in order to carry out unambiguous peak identification. Steryl esters with different sterol (i.e. cholesterol, lanosterol and dihydrolanosterol) and acid moieties either according to carbon number (i.e C10-C23) or isomeric forms (i.e. normal, iso and anteiso) have been identified. Identification of the sterol and acid moieties has been carried out by means of the mass spectral information obtained in the electron impact, chemical ionisation mode either in the positive or negative modes using methane, isobutane and ammonia as reagent gases. Isomeric identification has been achieved by chromatographic retention parameters (i.e. entire-chain length and fractional-chain length) and by the free fatty acid profile also present in lanolin.

Chromatography, Gas↗

PubMed2002

Systematic characterisation of long-chain aliphatic esters of wool wax by gas chromatography-electron impact ionisation mass spectrometry.

A detailed structural characterisation of the aliphatic high-molecular-mass esters extracted from raw wool based on high-temperature gas chromatography-electron impact ionisation mass spectrometry is described. The raw wool esters extracted are in the range of C37 to C54 (i.e., molecular mass 550-788). The selected ion chromatogram exhibited four isomers for the esters with an odd number of carbon atoms (i:a, i:n, a:n and n:n) and five for those with an even number of carbon atoms (i:i, a:a, i:n, a:n and n:n). Isomeric structural elucidation is discussed with respect to the long-chain fatty acid and long-chain fatty alcohol structures, on the basis of chromatographic retention behaviour and mass spectral information.

Esters↗

PubMed2002

Trace level determination of organochlorine, organophosphorus and pyrethroid pesticides in lanolin using gel permeation chromatography followed by dual gas chromatography and gas chromatography-negative chemical ionization mass spectrometric confirmation.

A methodology for multi-class pesticide determination at trace level in lanolin is presented. Gel permeation chromatography on a Bio-Beads SX-3 column followed by a dual GC chromatographic determination has been developed. The effluent of the analytical column (50% diphenyl-methyl- or 14% cyanopropyl-phenylpolysiloxane) was split into an electron-capture and a nitrogen-phosphorus detection system. The chromatographic system was optimised for 28 pesticides commonly used to control sheep pests and corresponding to organochlorine, organophosphorus and pyretroid classes. Identification has been carried out by gas chromatography coupled to negative chemical ionization mass spectrometry. Recoveries ranged from 72 to 94% and the detection limits from 20 to 97 ng/g depending on the pesticide class, the RSDs were below 10%. Finally, the developed analytical methodology has been successfully applied to the determination of pesticides in several lanolin samples.

Chromatography, Gas↗

PubMedDate not supplied

Comparative characterization of a wool-wax extract by two complementary chromatographic techniques.

A detailed characterization of lipids present in a wool-wax extract, obtained by supercritical fluid extraction, is presented. Thin-layer chromatography coupled to a flame ionization detector (TLC-FID) has been used as a screening technique to identify the different chemical classes of complex mixtures. Furthermore, to confirm peak identification obtained by TLC-FID and to check its suitability as a quality control technique, preparative TLC fractionation has been carried out by re-analyzing the different fractions obtained by TLC-FID and by gas chromatography coupled to mass spectrometry in the electron impact and in the chemical ionization modes. By means of this comparative study, the TLC-FID identification has been confirmed. Also, the complementarity of the different techniques used confirmed the identification of different lipid classes, namely fatty acids, alcohols, sterols, sterane diol, stanone, steryl sulphate, hydroxyacids, alkane diols, aliphatic and steryl esters, hydroxy steryl esters, triacylglycerol, diesters, and ceramides types II and VI.

Animals↗