Francesc Ventura

Organic indicators of groundwater pollution by a sanitary landfill

Abstract The organic composition of leachate from the Barcelona sanitary landfill is described. According to the low degree of stabilization of the disposed garbage the acid fraction accounts for 80–90% of the total organic extract. More than 50 individual organic components have been identified, indicating catabolic degradation of lipids (e.g. C 4 –C 11 carboxylic acids), proteins (e.g. indole derivatives) and lignins (e.g. p -hydroxyphenyl derivatives) or simply compounds originally present in the refuse that have been washed out by percolating waters (nicotine, caffeine, phthalates). To obtain a monitoring system for the groundwater pollution originated by this landfill leachate, an analytical method is proposed based on the GC-ECD fingerprinting of groundwater acidic extracts after derivatization with PFB bromide. The chromatogram contains carboxylic and phenolic components and the profiles exhibited by waters from several test wells in the downstream edge of the landfill were indicative of the suspected leachate pollution.

Stir bar sorptive extraction-thermal desorption-gas chromatography–mass spectrometry: An effective tool for determining persistent organic pollutants and nonylphenol in coastal waters in compliance with existing Directives

A multi-residual method based on stir bar sorptive extraction coupled with thermal desorption-gas chromatography-mass spectrometry (SBSE-TD-GC-MS) has been developed to measure 49 organic pollutants (organochlorine pesticides, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, polybrominated diphenyl ethers and nonylphenol) in seawater. Using 100ml of water, the method exhibited good linearity, with recoveries between 86% and 118% and relative standard deviation between 2% and 24% for almost all compounds. The method was applied to determine target contaminants in Catalonian seawater, including coastal areas, ports and desalination plant feed water. Overall individual compound levels oscillated between 0.16 and 597 ng l(-1); PAHs and nonylpenol were the compounds found at the highest concentrations. The method provided LODs between 0.011 and 2.5 ng l(-1), lower than the Environmental Quality Standards (EQS) fixed by Directive 2008/105/EC. In compliance with the directive, this method can be used as a tool to survey target compounds and is aimed at protecting coastal ecosystems from chemical pollution.

Occurrence of perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) in N.E. Spanish surface waters and their removal in a drinking water treatment plant that combines conventional and advanced treatments in parallel lines.

Perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) are two emerging contaminants that have been detected in all environmental compartments. However, while most of the studies in the literature deal with their presence or removal in wastewater treatment, few of them are devoted to their detection in treated drinking water and fate during drinking water treatment. In this study, analyses of PFOS and PFOA have been carried out in river water samples and in the different stages of a drinking water treatment plant (DWTP) which has recently improved its conventional treatment process by adding ultrafiltration and reverse osmosis in a parallel treatment line. Conventional and advanced treatments have been studied in several pilot plants and in the DWTP, which offers the opportunity to compare both treatments operating simultaneously. From the results obtained, neither preoxidation, sand filtration, nor ozonation, removed both perfluorinated compounds. As advanced treatments, reverse osmosis has proved more effective than reverse electrodialysis to remove PFOA and PFOS in the different configurations of pilot plants assayed. Granular activated carbon with an average elimination efficiency of 64±11% and 45±19% for PFOS and PFOA, respectively and especially reverse osmosis, which was able to remove ≥99% of both compounds, were the sole effective treatment steps. Trace levels of PFOS (3.0-21 ng/L) and PFOA (<4.2-5.5 ng/L) detected in treated drinking water were significantly lowered in comparison to those measured in precedent years. These concentrations represent overall removal efficiencies of 89±22% for PFOA and 86±7% for PFOS.

GC/MS, HPLC and FAB Mass Spectrometric Analysis of Organic Micropollutants in Barcelona's Water Supply

Water samples from Llobregat river entering two water work plants, Barcelona tap water and waste dumping samples taken along the river course were analyzed for trace organic contaminants by different procedures, liquid-liquid extraction, adsorption on granular activated carbon followed by GC/MS/DS. Ether insoluble organic fractions were analyzed and fractionated by HPLC with diode-array detection, followed by FAB and FAB-CID-MIKE characterisation. Results, after two years monitoring, proved that surfactants, plasticizers, ethyleneglycol derivatives, phosphates, hydrocarbons and other miscellaneous compounds can be considered as chronic pollutants of Llobregat river. Some of the identified compounds by GC/MS and FAB mass spectrometry have not been previously reported to occur in water.

Characterization of polyethoxylated surfactants and their brominated derivatives formed at the water treatment plant of Barcelona by GC/MS and FAB mass spectrometry

Abstract Polyethoxylated C 12 -C 15 alcohols, nonylphenols and [(nonylphenoxy) polyethoxy] acetic acid and their brominated derivatives were identified in the River Llobregat and the tap water of Barcelona by GC/MS and FAB mass spectrometry. Whereas GC/MS is limited to those compounds with a low polyethoxylation degree, FAB mass spectrometry is a fast and simple technique to determine surfactants with a high range of oligomers present in the samples. We believe that both techniques are complementary. The source of these compounds is the discharge of effluent wastes of surfactant industries and dyeing and textile processes. Their brominated derivatives are formed in the chlorination stages in the water works plant due to a high content of bromide ions in the upper course of the river.

Gas chromatography/mass spectrometry comprehensive analysis of organophosphorus, brominated flame retardants, by-products and formulation intermediates in water

A multiresidue method based on gas chromatography coupled to quadrupole mass spectrometry was developed to determine organophosphorus flame retardants, polybromodiphenyl ethers (BDEs 28, 47, 99, 100, 153, 154, 183 and 209), new brominated flame retardants, bromophenols, bromoanilines, bromotoluenes and bromoanisoles in water. Two ionization techniques (electron ionization--EI, and electron capture negative ionization--ECNI) and two acquisition modes (selected ion monitoring--SIM, and selected reaction monitoring--SRM) were compared as regards to mass spectral characterization, sensitivity and quantification capabilities. The highest sensitivity, at expenses of identification capacity, was obtained by GC-ECNI-MS/SIM for most of the compounds analyzed, mainly for PBDEs and decabromodiphenyl ethane while GC-EI-MS/MS in SRM was the most selective technique and permitted the identification of target compounds at the pg level, and identification capabilities increased when real samples were analyzed. This method was further used to evaluate the presence and behavior of flame retardants within a drinking water treatment facility. Organophosphorus flame retardants were the only compounds detected in influent waters at levels of 0.32-0.03 μg L⁻¹, and their elimination throughout the different treatment stages was evaluated.

Liquid chromatography coupled to tandem mass spectrometry and high resolution mass spectrometry as analytical tools to characterize multi-class cytostatic compounds

Cytostatic compounds used in the treatment of cancer have emerged as a new generation of water contaminants due to the continuous amounts administered to patients and to the fact that a variable proportion is excreted unchanged. In this study, we have evaluated the performance of liquid-chromatography-tandem mass spectrometry (LC-MS/MS) and high resolution mass spectrometry using an Orbitrap analyzer (LC-HRMS) for the multiresidue determination of multi-class cytostatic compounds. In a first step, ionization conditions were tested in positive electrospray mode and optimum fragmentation patterns were determined. For LC-MS/MS, two selected reaction monitoring (SRM) transitions were optimized and for LC-HRMS, the molecular ion with 5 ppm error and two product ions were defined. Following, the chromatographic conditions were optimized considering that compounds analyzed have a very different chemical structure and chromatographic behavior. The best performance was obtained with a Luna C18 column, which permitted the separation of the 26 compounds in 15 min. Finally, the performance of LC-MS/MS and LC-HRMS was compared in terms of linearity, sensitivity, intra and inter-day precision and overall robustness. While LC-MS/MS provided good identification capabilities due to selective SRM transitions, LC-Orbitrap proved to be 100 times more sensitive. This study provides a comprehensive overview on the MS conditions to determine the outmost used cytostatic compounds and provides a spectral library to be used for the identification of these compounds in water or biological matrices.

Identification of surfactants in water by fab mass spectrometry

Abstract An application of fast atom bombardment (FAB) for identification of some organic micro-pollutants was performed. A study of the most common surfactants, including non-ionic, cationic and anionic compounds was carried out and the results obtained used to build a table for rapid characterization of surfactants in real samples. Negative FAB and tandem mass spectrometry (CID-MIKE) were also occasionally employed, when two or more compounds gave the same series of peaks. Sensitivity limits for standards varied from low to upper nanogram range for cationic to anionic surfactants. Raw and drinking water extracts of Barcelona (N.E. Spain) were analysed and the most common surfactants and some brominated derivatives were identified.

Factors Influencing the High Content of Brominated Trihalomethanes in Barcelona's Water Supply (Spain)

Llobregat River is a heavy polluted river bearing a lot of industries including textile, galvanic, coal and salt works, pulp mill, farms and domestic waste-waters. The water works plant is located 7 Km from the mouth and receives all these discharges. The plant is able to potabilize 5,3 m 3 /s and employs prechlorination. coagulation with alum, settling, filtration (Pittsbourg F-200) and postchlorination.

Solid-phase microextraction for the determination of iodinated trihalomethanes in drinking water.

A headspace solid-phase microextraction (HS-SPME) method has been developed for the determination of iodinated trihalomethanes (ITHMs) in treated water samples. Mixed THMs (bromochloroido-, bromodiiodo-, chlorodiiodo-, dibromoiodo- and dichloroiodo-) were previously synthesized since commercial standards are not available. HS-SPME has shorter equilibration times than direct SPME, a cleaner background and a longer fiber life. Experimental parameters such as the selection of SPME coatings, sample volume, extraction time and addition of salts were studied. The Carbowax-divinylbenzene fiber appears to be the most suitable for the determination of ITHMs. Analytical parameters such as linearity, limit of detection and precision were also evaluated. HS-SPME was compared to liquid-liquid microextraction for the analyses of spiked treated water samples, obtaining a good agreement. It is concluded that HS-SPME has a great potential for drinking water analysis.