14th EuCheMS International Conference on Chemistry and the Environment ICCE 2013: IEC-WTC, Barcelona, Spain, 25-28 June 2013.

The 14th European Association of Chemical and Molecular Sciences (EuCheMS) International Conference on Chemistry and the Environment (ICCE 2013) took place on 25-28 June 2013 at the IEC and the WTC in Barcelona, Spain. The ICCE is a well-established biannual conference organized by the Division of Chemistry and the EuCheMS.

Water plasma functionalized CNTs/MnO2 composites for supercapacitors.

A water plasma treatment applied to vertically-aligned multiwall carbon nanotubes (CNTs) synthesized by plasma enhanced chemical vapour deposition gives rise to surface functionalization and purification of the CNTs, along with an improvement of their electrochemical properties. Additional increase of their charge storage capability is achieved by anodic deposition of manganese dioxide lining the surface of plasma-treated nanotubes. The morphology (nanoflower, layer, or needle-like structure) and oxidation state of manganese oxide depend on the voltage window applied during charge-discharge measurements and are found to be key points for improved efficiency of capacitor devices. MnO2/CNTs nanocomposites exhibit an increase in their specific capacitance from 678 Fg(-1), for untreated CNTs, up to 750 Fg(-1), for water plasma-treated CNTs.

Vertically aligned carbon nanotubes for microelectrode arrays applications.

In this work a methodology to fabricate carbon nanotube based electrodes using plasma enhanced chemical vapour deposition has been explored and defined. The final integrated microelectrode based devices should present specific properties that make them suitable for microelectrode arrays applications. The methodology studied has been focused on the preparation of highly regular and dense vertically aligned carbon nanotube (VACNT) mat compatible with the standard lithography used for microelectrode arrays technology.

Occurrence and fate of benzothiazoles and benzotriazoles in constructed wetlands.

A suite of benzothiazoles and benzotriazoles was analysed by comprehensive multi-dimensional gas chromatography coupled to time-of-flight mass spectrometry in four different wastewater treatment systems. The selected wastewater treatment systems include one conventional wastewater treatment plant (WWTP) and for the first time, two constructed wetlands. Although benzothiazole (BT), 2-(methylthio)benzothiazole (MTBT), 2-hydroxybenzothiazole (OHBT) and benzotriazole (BTri) occurred in all the raw wastewater samples, 4- and 5-methylbenzotriazoles (4- and 5-TTri) were only detected in the industrially impacted wastewater. Concentrations of benzothiazoles and benzotriazoles in raw wastewater ranged from 0.2 to 2.2 microg L(-1) and from 0.06 to 36.2 microg L(-1), respectively. The benzothiazoles removal efficiencies ranged from zero to up to 80% in the conventional WWTP and from 83 to 90% in constructed wetlands. For BTri, removal efficiencies ranged from 65 to 70% and from 89 to 93% in conventional WWTP and constructed wetlands, respectively. The higher performance of CWs in the removal of these compounds might be attributed to the contribution of biodegradation, photodegradation and plant uptake.

Part-per-trillion determination of pharmaceuticals, pesticides, and related organic contaminants in river water by solid-phase extraction followed by comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry.

An analytical procedure based on comprehensive two-dimensional gas chromatography (GC x GC) coupled with time-of-flight mass spectrometry (TOF-MS) for the simultaneous determination of 97 organic contaminants at trace concentration in river water is presented. The target analytes included 13 pharmaceuticals, 18 plasticizers, 8 personal care products, 9 acid herbicides, 8 triazines, 10 organophosphorous compounds, 5 phenylureas, 12 organochlorine biocides, 9 polycyclic aromatic hydrocarbons (PAHs), and 5 benzothiazoles and benzotriazoles. The best resolution of the target analytes in the contour plots was obtained when a nonpolar stationary phase was used in the first dimension and polar one in the second. However, in the opposite configuration, polar-nonpolar, the retention time in the second dimension exhibited a strong correlation with the log Kow (p < 0.01), and it was proposed as an additional identification criteria. The developed methodology is based on a polymeric solid-phase extraction followed by in GC-port methylation and GC x GC/TOF-MS determination. Moreover, limits of detection (LODs) and quantification (LOQs) ranged from 0.5 to 100 ng/L and from 2 to 185 ng/L, respectively. Repeatability was always lower than 20%. Finally, the developed method has been successfully applied to the determination of incurred target analytes in four river waters subjected to a different anthropogenic pressure.

Assessment of the emission of PCDD/Fs and dioxin-like PCBs from an industrial area over a nearby town using a selective wind direction sampling device.

The development of new sampling devices or strategies to assess the concentration of persistent organic pollutants (POPs) in the environment has increased in the last two decades. In this study, a selective sampling device was used to evaluate the impact of potential local sources of polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/Fs) and dioxin-like polychlorinated biphenyl (dl-PCBs) emissions on the ambient air levels of such compounds in a town near an important industrial estate. Average concentrations of target compounds of up to 2.5 times for PCDD/Fs and 2 times for dl-PCBs were found to come from the industrial state confirming this area as the main responsible for the majority of such compounds reaching the town. This finding was supported by a PCDD/F and dl-PCB sample profile analysis and a principal component analysis (PCA), which established a direct link between the dioxin-like compounds found in the samples collected in the town and their source.

Photo-solid-phase microextraction of selected indoor air pollutants from office buildings. Identification of their photolysis intermediates.

Photo-solid-phase microextraction (photo-SPME) has been employed to study the photolysis of three common indoor air pollutants: coumarin, butylated hydroxytoluene, 2,6-diisopropylnaphthalene. Analytes were first extracted by SPME, and the fibre was subsequently exposed to an irradiation source (i.e. xenon arc or low-pressure mercury lamp) for the selected time (from 2 to 120 min). Analyses of the irradiated fibres were carried out by gas chromatography-mass spectrometry (GC-MS) detection. Photodecay kinetics exhibited a first-order behaviour and their rate constants and half-life times were estimated. Twenty-five photoproducts have been tentatively identified by means of their mass spectra. On the basis of the identified transformation compounds, some photodegradation pathways were proposed. The photoformation-photodecay kinetics of the identified by-products were also monitored by photo-SPME. To the best of our knowledge, photolytic routes for coumarin, butylated hydroxytoluene and 2,6-diisopropylnaphthalene have not been previously investigated.

Characterization of benzothiazoles, benzotriazoles and benzosulfonamides in aqueous matrixes by solid-phase extraction followed by comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry.

Benzothiazoles, benzotriazoles and benzosulfonamides are high-production-volume chemicals found in various environmental aqueous samples that should be considered as emerging pollutants. This study examines the suitability of comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC x GC-TOF-MS) for the characterization of benzothiazoles, benzotriazoles and benzosulfonamides in aqueous matrices. Solid-phase extraction was optimized in order to ensure the proper preconcentration of these contaminants prior to their analysis. Column selection, in both the first and second dimensions, was optimized to ensure a good chromatographic separation of the target analytes and of the potential interfering compounds extracted from the matrix. Several column phases were tested. The combined power of two-dimensional separation was fully illustrated by identifying minor compounds and avoiding the overestimations usually made by one-dimensional systems. Finally, the suitability of GC x GC-TOF-MS to quantify the aforementioned emerging pollutants was proven by determining those pollutants in several real samples such as river water, effluent from a wastewater treatment plant, and raw sewage.

Advances in the determination of degradation intermediates of personal care products in environmental matrixes: a review.

In this review, recent methods developed for the determination of degradation intermediates of personal care products in environmental matrixes focusing on the extraction and determination steps are discussed. The five classes of personal care products evaluated are stimulants, fragrances, sunscreens, antimicrobials, and insect repellents. Methods are critically reviewed in terms of the analytical steps involved in the analysis, sample pretreatment, separation, and detection as well as the different confirmation strategies employed. Preconcentration from aqueous matrixes was performed by solid-phase extraction, liquid-liquid extraction, or solid-phase microextraction, allowing the simultaneous extraction of parent compounds and their degradation intermediates. Following the extraction and cleanup steps, the identification and quantification of degradation intermediates of personal care products at environmental levels (i.e., parts per trillion to parts per billion range) is usually performed by using mass spectrometry techniques such as single quadrupole mass spectrometry and more recently by time-of-flight mass spectrometry or tandem mass spectrometry. The main scope of this review is to critically evaluate the current state of the art of the analytical techniques used and to identify the research needs in the determination of degradation intermediates of personal care products in environmental matrixes.

Allylnitrile metabolism by CYP2E1 and other CYPs leads to distinct lethal and vestibulotoxic effects in the mouse.

This study addressed the hypothesis that the vestibular or lethal toxicities of allylnitrile depend on CYP2E1-mediated bioactivation. Wild-type (129S1) and CYP2E1-null male mice were exposed to allylnitrile at doses of 0, 0.5, 0.75, or 1.0 mmol/kg (po), following exposure to drinking water with 0 or 1% acetone, which induces CYP2E1 expression. Induction of CYP2E1 activity by acetone in 129S1 mice and lack of activity in null mice was confirmed in liver microsomes. Vestibular toxicity was assessed using a behavioral test battery and illustrated by scanning electron microscopy observation of the sensory epithelia. In parallel groups, concentrations of allylnitrile and cyanide were assessed in blood after exposure to 0.75 mmol/kg of allylnitrile. Following allylnitrile exposure, mortality was lower in CYP2E1-null than in 129S1 mice, and increased after acetone pretreatment only in 129S1 mice. This increase was associated with higher blood concentrations of cyanide. In contrast, no consistent differences were recorded in vestibular toxicity between 129S1 and CYP2E1-null mice, and between animals pretreated with acetone or not. Additional experiments evaluated the effect on the toxicity of 1.0 mmol/kg allylnitrile of the nonselective P450 inhibitor, 1-aminobenzotriazole, the CYP2E1-inhibitor, diallylsulfide, and the CYP2A5 inhibitor, methoxsalen. In 129S1 mice, aminobenzotriazole decreased both mortality and vestibular toxicity, whereas diallylsulfide decreased mortality only. In CYP2E1-null mice, aminobenzotriazole and methoxsalen, but not diallylsulfide, blocked allylnitrile-induced vestibular toxicity. We conclude that CYP2E1-mediated metabolism of allylnitrile leads to cyanide release and acute mortality, probably through alpha-carbon hydroxylation, and hypothesize that epoxidation of the beta-gamma double bond by CYP2A5 mediates vestibular toxicity.

Determination of cyanide and volatile alkylnitriles in whole blood by headspace solid-phase microextraction and gas chromatography with nitrogen phosphorus detection.

Simultaneous determination of cyanide and volatile alkylnitriles such as acetonitrile, cis- and trans-crotononitrile, allylnitrile and butyronitrile at low ppb concentration on whole blood (rat and mice) by headspace solid-phase microextraction (HS-SPME) followed by gas chromatography (GC) with nitrogen phosphorus detection has been achieved for the first time. SPME extraction time and temperature were optimized using a star experimental design. Optimum conditions for cyanide extraction were chosen to analyze unspiked blood samples containing alkylnitriles as that analyte occurs at the lowest concentrations. For all analytes, the developed methodology yielded good quality parameters. In all cases, good reproducibility (relative standard deviation < or =12%), detection limits (<3ng mL(-1)) and quantification limits (<4 ng mL(-1)) were recorded.

Differential role of CYP2E1-mediated metabolism in the lethal and vestibulotoxic effects of cis-crotononitrile in the mouse.

Several alkylnitriles are toxic to sensory systems, including the vestibular system, through yet undefined mechanisms. This study addressed the hypothesis that the vestibular toxicity of cis-crotononitrile depends on CYP2E1-mediated bioactivation. Wild-type (129S1) and CYP2E1-null female mice were exposed to cis-crotononitrile at 0, 2, 2.25 or 2.5 mmol/kg (p.o.) in either a baseline condition or following exposure to 1% acetone in drinking water to induce CYP2E1 expression. The exposed animals were assessed for vestibular toxicity using a behavioral test battery and through surface observation of the vestibular sensory epithelia by scanning electron microscopy. In parallel groups, concentrations of cis-crotononitrile and cyanide were assessed in whole blood. Contrary to our hypothesis, CYP2E1-null mice were slightly more susceptible to the vestibular toxicity of cis-crotononitrile than were control 129S1 mice. Similarly, rather than enhance vestibular toxicity, acetone pretreatment actually reduced it slightly in 129S1 controls, although not in CYP2E1-null mice. In addition, significant differences in mortality were recorded, with the greatest mortality occurring in 129S1 mice after acetone pretreatment. The highest mortality recorded in the 129S1+acetone mice was associated with the lowest blood concentrations of cis-crotononitrile and the highest concentrations of cyanide at 6 h after nitrile exposure, the time when deaths were initially recorded. We conclude that cis-crotononitrile is a CYP2E1 substrate as hypothesized, but that CYP2E1-mediated metabolism of this nitrile is not necessary for vestibular toxicity; rather, this metabolism constitutes a major pathway for cyanide release and subsequent lethality.

Prestige oil spill. III. Fate of a heavy oil in the marine environment.

More than 200 oil samples were collected along the Northern Spanish coast, from December 2002 to December 2003, as part of the extensive monitoring program carried out by the Spanish Marine Safety Agency after the Prestige heavy oil spill (November 13, 2002). The GC FPD/ FID and comprehensive GC x GC/TOFMS sample profiles revealed the main characteristics of the oil residues. Chemical fingerprinting of the aliphatic and aromatic fractions by GC/ MS was performed to determine the source of the oil as well as to follow its weathering at sea. The (n-C13 + n-C14)/(n-C25 + n-C26), n-C18/phytane, and methylnaphthalene [(N + N1)/N2] ratios were found to be useful for assessing the evaporation, biodegradation, and dissolution processes, respectively. Other indicators of more advanced degradation processes, including photo-oxidation, were unaltered, showing the low incidence of natural weathering processes on the spilled heavy oil 1 year after the accident. The survey also demonstrated the occurrence of continued discharges of ballast waters at sea and the need for a more stringent surveillance of the area, beyond accidental oil spills.

Influence of water filtration on the determination of a wide range of dissolved contaminants at parts-per-trillion levels.

The adsorption of dissolved organic contaminants on glass fibre filters throughout water dissolved/particulate phase decoupling studies was examined. A total of 49 different compounds were considered at low concentration levels (ng L(-1)), including PAHs, PCBs, organochlorine and organophosphorus pesticides, triazines, thiocarbamates, pyrethroids, phosphate esters and caffeine. Their adsorption on the filters was positively correlated with their log Kow and solubilities, indicating that filter adsorption increased with hydrophobicity. The influence of water properties (i.e. salinity and dissolved organic carbon (DOC) content) was also studied by means of a star experimental design (n=11). Salinity was the main factor in increasing the adsorption, due to the salting out effect. The influence of DOC suggested that part of the contaminant losses during water filtration may have been caused by the retention on the organic matter adsorbed on the filter surface. Nevertheless, a decrease in filter retention was observed for water with the highest DOC contents, which was probably due to an enhancement of the contaminant solubility in these conditions. Although several factors may control the adsorption process in naturally occurring waters, the extent of the retention of dissolved target analytes on the glass fibre filters should not be underestimated in the analysis of hydrophobic contaminants in marine and estuarine waters at very low concentrations (ppt level).

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.

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.

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.

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.

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.