Novel analytical strategies for the analysis of organic micropollutants in environmental samples = nuevas estrategias analíticas para el análisis de contaminantes orgánicos en muestras ambientales

Tesis doctoral inédita. Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Química Analítica y Análisis Instrumental. Fecha de lectura: 11-05-2012. Tesis doctoral con mención europe

Lipid and fatty acid composition, and persistent organic pollutant levels in tissues of migrating Atlantic bluefin tuna (Thunnus thynnus, L.) broodstock

Lipid class, fatty acid and POP levels were measured in migrating Atlantic bluefin tuna (ABT) tissues caught off the Barbate coast, Spain. Tissue lipids were largely characterized by triacylglycerol, reflecting large energy reserves accumulated prior to reproductive migration. Fatty acid compositions of muscle, liver and adipose exhibited similar profiles, whereas gonads showed a higher affinity for docosahex- aenoic acid. Tissue POP concentrations correlated positively with percentage triacylglycerol and nega- tively with polar lipids. Highest POP concentrations were in adipose and lowest in gonads, reflecting lipid content. DL-PCBs contributed most to total PCDD/F þ DL-PCB levels, with mono-ortho concentrations higher in tissues, whereas non-ortho PCBs contributed greater WHO-TEQs due to differences in TEFs. PBDE47 was the most prominent BDE congener in tissues, probably through biotransformation of BDE99 and other higher brominated congeners. The perceived POP risk from ABT consumption should be balanced by the well-established beneficial effects on human health of omega-3 fatty acids

Miniaturization of analytical methods

This chapter highlights miniaturization in sample preparation as a valuable alternative for green analytical chemistry. The current state of the art is discussed on the basis of examples selected from representative application areas, including biomedical, environmental and food analysis, and involving conventional instrumental techniques for final determination of the target compounds. The emphasis is on those techniques and approaches that have already demonstrated their practicality by the analysis of real-life samples, and in particular on those dealing with the accurate determination of minor organic components. The potential of recent developments in this field for sample treatment simplification and complete hyphenation of analytical processes are discussed and the most pressing remaining limitations evaluated.Peer reviewe

Miniaturización en la preparación de muestras

Peer reviewe

Novel approaches for fast sample preparation of POPs in complex fatty (semi-)solid matrices

Trabajo presentado al 34th International Symposium on Halogenated Persistent Organic Pollutants (Dioxin 2014), celebrado en Madrid (España) del 31 de agosto al 5 de septiembre de 2014.The developments achieved during the last decades in the field of analytical instrumentation allow nowadays performing determinations of persistent organic pollutants (POPs) at levels that we can hardly imagine years ago while keeping standards of accuracy and selectivity in line with those set in current legislations even with relatively simple bench-top-type instruments.Author thanks MINECO for project CTQ2012-32957.Peer reviewe

Comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry for the identification of organobrominated compounds in bluefin tuna

This study evaluates comprehensive two-dimensional gas chromatography (GC × GC) coupled to time-of-flight mass spectrometry (GC × GC–ToF MS) for the simultaneous analysis of several classes of organobromines (OBs), including polybrominated diphenyl ethers (PBDEs), polybrominated biphenyls (PBBs), methoxylated PBDEs (MeO-PBDEs), several halogenated naturally produced compounds (HNPs) and eight novel brominated flame retardants (NBFRs), polybrominated hexahydroxanthene derivates (PBHDs), 2,4,6-tribromoanisole and a mixed halogenated compound (MHC-1), in bluefin tuna muscles. The proposed methodology maximised separation of both within and among OB families, and among these and other halogenated micropollutants detected in these samples and co-extracted matrix components. Special attention has been paid to solve co-elution problems observed during the analysis of OBs with one-dimensional GC-based techniques. Satisfactory separation among several relevant PBDEs and MeO-PBDEs has been obtained allowing their unambiguous determination in a single run. Additional studies were conducted to identify selected NBFRs and HNPs. 2,4-Dibromoanisole, a dibromophenol isomer and hexabromobenzene were identified in the investigated samples. Several new tri- and tetra-BHD derivates were also identified, indicating that these compounds could apparently exist as structured families in nature. In addition, a tetrabrominated diMeO-biphenyl and two tetrabrominated diMeO-BDEs were also tentatively identified.Miren Pena acknowledges the Spanish Science and Innovation Ministry (MICINN) for the financial support via a FPU grant and AP2006-02137. Miren Pena and Lourdes Ramos also thank MICINN (CTQ-2006-14993/BQU and AGL2009-11909) and CM and FEDER program (project S2009/AGR-1464, ANALISYC-II) for financial support. Adrian Covaci is financially supported by a postdoctoral fellowship from the Research Scientific Foundation – Flanders (FWO).Peer reviewe

Comprehensive two-dimensional gas chromatography for the analysis and fast screening of polycyclic aromatic hydrocarbons in sediments

Trabajo presentado en el 36th International Symposium on Capillary Chromatography (ISCC), celebrado en Riva del Garda (Italia) del 27 de mayo al 1 de junio de 2012.This study evaluates the feasibility of comprehensive two-dimensional gas chromatography- time-of-flight mass spectrometry (GC×GC–ToF MS) for the determination of the 15+1 priority EU polycyclic aromatic hydrocarbons (PAHs) in sediments from the Sancti-Petri Channel (Cadiz Bay, Spain). The study area is a tidal channel of about 18 km, which connects the southern part of the Bay of Cádiz with the Atlantic Ocean. This protected natural enclave is potentially affected by different human and industrial activities. Firstly, standard solutions were used to optimise the separation by GC×GC–ToF MS of the investigated PAHs. Special attention was paid to critical PAH groups usually affected by chromatographic co-elution. The performance of the proposed methodology for the determination of the target compounds in real-life samples was evaluated by the analysis of sediment extracts prepared using a previously optimised microwave-assisted extraction-based method followed by solid-phase extraction purification. The developed methodology was then applied to the analysis of the 16 test PAHs in 17 sediments sampled along the 18-Km channel. The influence of the different industrial and human activities developed in the study area became evident though both, the detected PAH levels, and the divergent profiles observed for the compounds in the analysed sediments. Regarding this last aspect, the feasibility of a visualisation approach based on the use of size-normalised bubbles for the fast screening of PAH occurrence and the tentative identification of the potential major pollution sources was evaluated.Authors thank projects CTQ-2006-14993/BQU, AGL2009-11909 and S-2009/AGR-1464 for financial support.Peer Reviewe

Comprehensive two-dimensional gas chromatographytime-of-flight mass spectrometry for the identification of organobrominated compounds in bluefin tuna

This study evaluates comprehensive two-dimensional gas chromatography (GC × GC) coupled to time-of-flight mass spectrometry (GC × GC–ToF MS) for the simultaneous analysis of several classes of organobromines (OBs), including polybrominated diphenyl ethers (PBDEs), polybrominated biphenyls (PBBs), methoxylated PBDEs (MeO-PBDEs), several halogenated naturally produced compounds (HNPs) and eight novel brominated flame retardants (NBFRs), polybrominated hexahydroxanthene derivates (PBHDs), 2,4,6-tribromoanisole and a mixed halogenated compound (MHC-1), in bluefin tuna muscles. The proposed methodology maximised separation of both within and among OB families, and among these and other halogenated micropollutants detected in these samples and co-extracted matrix components. Special attention has been paid to solve co-elution problems observed during the analysis of OBs with one-dimensional GC-based techniques. Satisfactory separation among several relevant PBDEs and MeO-PBDEs has been obtained allowing their unambiguous determination in a single run. Additional studies were conducted to identify selected NBFRs and HNPs. 2,4-Dibromoanisole, a dibromophenol isomer and hexabromobenzene were identified in the investigated samples. Several new tri- and tetra-BHD derivates were also identified, indicating that these compounds could apparently exist as structured families in nature. In addition, a tetrabrominated diMeO-biphenyl and two tetrabrominated diMeO-BDEs were also tentatively identified.Miren Pena acknowledges the Spanish Science and Innovation Ministry (MICINN) for the financial support via a FPU grant and AP2006-02137. Miren Pena and Lourdes Ramos also thank MICINN (CTQ-2006-14993/BQU and AGL2009-11909) and CM and FEDER program (project S2009/AGR-1464, ANALISYC-II) for financial support. Adrian Covaci is financially supported by a postdoctoral fellowship from the Research Scientific Foundation – Flanders (FWO).Peer reviewe

GCxGC-ToF MS for the analysis of anthropogenic and naturally produced organobrominated compounds

Trabajo presentado al 31st International Symposium on Halogenated Persistent Organic Pollutants (Dioxin 2011), celebrado en Bruselas (Bélgica) del 20 al 24 de agosto de 2011.Comprehensive two-dimensional gas chromatography (GC×GC) has gradually been introduced to solve some separation problems found during the analysis with one-dimensional GC. The use of high speed time-of-flight mass spectrometry (HS-ToF MS) as a detector for GC×GC (GC×GC–ToF MS) adds an additional dimension to the analysis allowing unambiguous determination based on nominal mass. This is especially relevant for environmental applications dealing with the determination of individual isomers belonging to complex families of micropollutants, e.g. polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and other closely related persistent organic pollutants (POPs). Many studies have proved that one-dimensional GC systems, especially when combined with MS detectors, provide enough resolution to allow unambiguous determination of relevant congeners within complex families, such as PCBs, PBDEs and PCDD/Fs. However, in these studies, either an exhaustive clean-up and fractionation of the extracts or several GC runs are typically required, especially when different classes of analytes have to be determined in the same extracts. In addition, most studies are target-orientated and information concerning the possible presence of other relevant known and especially unknown micropollutants is lost. In this context, GC×GC and, especially GC×GC–ToF MS, are powerful analytical tools that simultaneously contribute to simplify sample treatment and allow simultaneous determination of trace compounds from different analytes classes, while preserving complete information regarding non-targeted compounds. The feasibility of the technique to provide structured chromatograms is an additional feature that efficiently contribute to the tentative identification of analytes and families of analytes for which standards are not available and so to the (virtual) identification of unknown compounds.M. Pena acknowledges MICINN for financial support via a FPU grant and AP2006-02137. M. Pena and L. Ramos also thank MICINN (CTQ-2006-14993/BQU) and CM and FEDER program (project S2009/AGR-1464, ANALISYC-II) for financial support. A. Covaci is financially supported by a postdoctoral fellowship from the FWO. Samples were provided for analysis by Dr. S. Corsolini (University of Siena, Italy)Peer reviewe

Environmental analysis

This chapter discusses the advantages and limitations of the use of 2D gas chromatography (GCxGC) for the analysis of organic (semi-) volatile micropollutants in environmental matrices through selected applications that represent the current state-of-the-art in three main research fields: the analysis of organohalogenated pollutants, the determination of other nonhalogenated toxic compounds, and the enantiomeric analysis of chiral contaminants. GCxGC was rapidly incorporated in the analysis of organohalogenated compounds. Most of the research is carried out with alternative detectors—such as the flame ionization detector (FID) and the electron-capture detector (ECD)—in the early stage of development of the technique, with a clear preference for the micro-electron-capture detector (μECD) and time-of-flight mass spectrometry (ToF MS) in the past decade. A detailed study of the influence of the different experimental parameters affecting the modulation and acquisition data processes on the detectability and final identification of pesticides with GCxGC–ToF MS is presented in the chapter. The chapter also discusses the analysis of chiral pollutants in complex environmental samples.Peer reviewe