Tratamiento fotocatalítico en fase gaseosa de compuestos orgánicos volátiles liberados al ambiente por actividades industriales

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Química Agrícola, Geología y Geoquímica. Fecha de lectura: 06-07-200

Optimization of quadrupole ion storage mass spectrometric conditions for the analysis of selected polybrominated diphenyl ethers. Comparative approach with negative chemical ionization and electron impact mass spectrometry

8 pages, 4 figures, 3 tables.-- PMID: 15468104 [PubMed].Gas chromatography coupled to quadrupole ion storage mass spectrometry (QISTMS) operating in the non-resonant mode is presented as an innovative approach for the analysis of selected polybrominated diphenyl ethers (PBDEs). Although reductions in complexity and time needed for optimization are achieved in comparison with the resonant option, precise adjustment of the mass spectrometric conditions is required. Differences in isolation and fragmentation patterns of target species with degree of bromination were observed. The reliability of the method was confirmed by using standard solutions through the evaluation of certain quality parameters such as accuracy (92-108%), injection repeatability and reproducibility (coefficient of variation below 10% and 15%, respectively). Detection limits ranged from 62 to 621 fg, providing sensitivity similar to that of negative chemical ionisation (NCIMS) and greater than that of electron ionization mass spectrometry. The applicability of QISTMS method to real samples and matrix effects were evaluated through the analysis of some PBDE congeners in a sewage sludge sample from a Spanish waste-water treatment plant. Comparable results were obtained using QISTMS and NCIMS. According to these observations, QISTMS performed in the non-resonant mode may constitute a low-cost, rapid and reliable alternative to high-resolution devices for the analysis of selected PBDEs in environmental samples.Peer reviewe

Analysis of dioxins and furans in environmental samples by GC-ion-trap MS/MS

7 pages, 1 figure, 5 tables.-- PMID: 15099726 [PubMed].-- Printed version published Jun 2004.The work aims to characterise PCDDs/Fs in environmental matrices by high resolution gas chromatography coupled to low resolution quadrupole ion-trap mass spectrometry (GC-QITMS/MS). In particular, the study was mainly focused in different environmental samples such as sewage sludge, soils, and sediments and in combustion residues as fly ashes. Previous experiences have already detected and quantified PCDDs/PCDFs in all matrices studied. Moreover, isomer-specific analysis of 2,3,7,8-PCDDs/Fs compounds corroborated good correlation between GC-QITMS/MS and a well-established technique such as high resolution mass spectrometry (HRMS). Finally, QC measures included the participation in intercalibration exercises. Successful results were achieved using GC-QITMS/MS in the analysis of fly ashes, soils and sediment materials. In general, GC-QITMS/MS constitutes an interesting alternative for routine analysis of dioxins in such as matrices.Peer reviewe

Occurrence of polybrominated diphenylethers, polychlorinated dibenzo-p-dioxins, dibenzofurans and biphenyls in coastal sediments from Spain

9 pages, 7 figures.-- PMID: 15862403 [PubMed].-- Printed version published Aug 2005.Fifteen sediment samples were analysed in order to determine their content of polybrominated diphenylethers (PBDEs), polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and biphenyls (PCBs). Samples were collected from several hot spots on the Spanish coast, such as the harbours of Almeria and Tarragona, and the mouths of the Besós and Llobregat rivers in Barcelona. A generic analytical procedure based on Soxhlet extraction followed by an automated cleanup system and gas chromatography-ion trap-mass spectrometry was employed for determining the toxic congeners of PCDDs and PCDFs, as well as dioxin-like PCBs. As regards PBDE determinations, a rapid method based on the use of selective pressurized liquid extraction followed by gas chromatography-negative ion chemical ionization-mass spectrometry was applied. Total toxicity equivalent (WHO-TEQ) values were calculated using the toxicity equivalent factors proposed by WHO for dioxin-like PCBs, PCDDs and PCDFs. WHO-TEQ values ranged from 0.3 to 75 pg/g dry weight (dw), with PCB contribution on the toxicity of the samples between 1 and 84%. Total PBDE levels ranged from 2.7 to 134 ng/g dw, with BDE-209 contribution on the total PBDE contamination between 50 and 99%.Decabrominated diphenyl ether makes a substantial contribution to the total PBDE contamination found in Spanish coastal sediments.This work was supported by the Ministerio de Ciencia y Tecnología (TRACOAL, PPQ2001-1805-CO3-01) and by the European Union, and reflects only the authors' views and the European Community is not liable for any use that maybe made of the information contained there in “Horizontal Standards on Organic Micro-pollutants for Implementation of EU Directives on Sludge, Soil and Treated Bio-waste” (HORIZONTAL-ORG) (Contract no.: SSPI-CT-2003-502411) and got also financial support from the Ministry of Science and Education (Project number CTM2004-20246-E).Peer reviewe

Occurrence of polybrominated diphenylethers, polychlorinated dibenzo-p-dioxins, dibenzofurans and biphenyls in coastal sediments from Spain

9 pages, 7 figures.-- PMID: 15862403 [PubMed].-- Printed version published Aug 2005.Fifteen sediment samples were analysed in order to determine their content of polybrominated diphenylethers (PBDEs), polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and biphenyls (PCBs). Samples were collected from several hot spots on the Spanish coast, such as the harbours of Almeria and Tarragona, and the mouths of the Besós and Llobregat rivers in Barcelona. A generic analytical procedure based on Soxhlet extraction followed by an automated cleanup system and gas chromatography-ion trap-mass spectrometry was employed for determining the toxic congeners of PCDDs and PCDFs, as well as dioxin-like PCBs. As regards PBDE determinations, a rapid method based on the use of selective pressurized liquid extraction followed by gas chromatography-negative ion chemical ionization-mass spectrometry was applied. Total toxicity equivalent (WHO-TEQ) values were calculated using the toxicity equivalent factors proposed by WHO for dioxin-like PCBs, PCDDs and PCDFs. WHO-TEQ values ranged from 0.3 to 75 pg/g dry weight (dw), with PCB contribution on the toxicity of the samples between 1 and 84%. Total PBDE levels ranged from 2.7 to 134 ng/g dw, with BDE-209 contribution on the total PBDE contamination between 50 and 99%.Decabrominated diphenyl ether makes a substantial contribution to the total PBDE contamination found in Spanish coastal sediments.This work was supported by the Ministerio de Ciencia y Tecnología (TRACOAL, PPQ2001-1805-CO3-01) and by the European Union, and reflects only the authors' views and the European Community is not liable for any use that maybe made of the information contained there in “Horizontal Standards on Organic Micro-pollutants for Implementation of EU Directives on Sludge, Soil and Treated Bio-waste” (HORIZONTAL-ORG) (Contract no.: SSPI-CT-2003-502411) and got also financial support from the Ministry of Science and Education (Project number CTM2004-20246-E).Peer reviewe