The interaction of ozone and water vapor with spark discharge soot particles coated with the five-ring polycyclic aromatic hydrocarbon benzo[a]pyrene (BaP) has been investigated in aerosol flow tube experiments at ambient temperature and pressure (296 K, 1 atm). The investigated range of ozone volume mixing ratio (VMR) and relative humidity (RH) was 0-1 ppm and 0-25%, respectively. The observed gas-phase ozone losses and pseudo-first-order BaP decay rate coefficients exhibited Langmuir-type dependencies on gas-phase ozone concentration and were reduced in the presence of water vapor, which indicates rapid, reversible and competitive adsorption of O 3 and H 2 O on the particles followed by a slower surface reaction between adsorbed O 3 and BaP. At low ozone VMR and RH, the half-life of surface BaP molecules was found to be shorter than previously reported (∼ 5 min at 30 ppb O 3 under dry conditions). At higher RH and for multilayer BaP surface coverage, however, a strong increase of BaP half-life was observed and can be attributed to competitive H 2 O adsorption and to surface/bulk shielding effects, respectively. From four independent sets of ozone loss and BaP decay measurement data the following parameters have been derived: O 3 and H 2 O Langmuir adsorption equilibrium constants K O 3 ) (2.8 ( 0.2) × 10 -13 cm 3 and K H 2 O ) (2.1 ( 0.4) × 10 -17 cm 3 , maximum pseudo-first-order BaP decay rate coefficient k 1,4 ) (0.015 ( 0.001) s -1 , adsorption site surface concentration [SS] S ) (5.7 ( 1.7) × 10 14 cm -2 . On the basis of these values, a second-order BaP-O 3 surface reaction rate coefficient k 2,s ) (2.6 ( 0.8) × 10 -17 cm 2 s -1 can be calculated, and estimates for the mean surface residence times and adsorption enthalpies of O 3 and H 2 O have been derived: τ O 3 ≈ 5-18 s; τ H 2 O ≈ 3 ms, ∆H ads,O 3 ≈ -(80-90) kJ mol -1 , ∆H ads,H 2 O ≈ -50 kJ mol -1 . The results and their atmospheric implications are discussed in view of related studies.

In this article, a dataset from a collaborative non-target screening trial organized by the NORMAN Association is used to review the state-of-the-art and discuss future perspectives of non-target screening using high resolution mass spectrometry in water analysis. A total of 18 institutes from 12 European countries analysed an extract of the same water sample collected from the River Danube with either one or both of liquid and gas chromatography coupled with mass spectrometric detection. This article focuses mainly on the use of high resolution screening techniques with target, suspect and non-target workflows to identify substances in environmental samples. Specific examples are given to highlight major challenges such as isobaric and co-eluting substances, dependence on target and suspect lists, formula assignment, the use of retention information and the confidence of identification. Approaches and methods applicable to unit resolution data are also discussed. While most substances were identified using high resolution data with target and suspect screening approaches, some participants proposed tentative non-target identifications. This comprehensive dataset revealed that non-target analytical techniques are already considerably harmonized between the participants, but the data processing remains time-consuming. Although the dream of a "fully-automated identification workflow" remains elusive in the short-term, important steps in this direction have been taken, exemplified in the growing popularity of suspect screening approaches. Major recommendations to improve non-target screening include better integration and connection of desired features into software packages, the exchange of target and suspect lists and the contribution of more spectra from standard substances into (openly accessible) databases.

Gracia-Lor, E. et al. (2017) Measuring biomarkers in wastewater as a new source of epidemiological information: current state and future perspectives. Environment International, 99, pp. 131-150. (doi:10.1016International, 99, pp. 131-150. (doi:10. /j.envint.2016 This is the author's final accepted version.There may be differences between this version and the published version. You are advised to consult the publisher's version if you wish to cite from it.http://eprints.gla.ac.uk/133949/

SummaryDetoxification of xenobiotic compounds and heavy metals is a pivotal capacity of organisms, in which glutathione (GSH) plays an important role. In plants, electrophilic herbicides are conjugated to the thiol group of GSH, and heavy metal ions form complexes as thiolates with GSH-derived phytochelatins (PCs). In both detoxification processes of plants, phytochelatin synthase (PCS) emerges as a key player. The enzyme is activated by heavy metal ions and catalyzes PC formation from GSH by transferring glutamylcysteinyl residues (c-EC) onto GSH. In this study with Arabidopsis, we show that PCS plays a role in the plant-specific catabolism of glutathione conjugates (GS-conjugates). In contrast to animals, breakdown of GS-conjugates in plants can be initiated by cleavage of the carboxyterminal glycine residue that leads to the generation of the corresponding c-EC-conjugate. We used the xenobiotic bimane in order to follow GS-conjugate turnover. Functional knockout of the two PCS of Arabidopsis, AtPCS1 and AtPCS2, revealed that AtPCS1 provides a major activity responsible for conversion of the fluorescent bimane-GS-conjugate (GS-bimane) into c-ECbimane. AtPCS1 deficiency resulted in a c-EC-bimane deficiency. Transfection of PCS-deficient cells with AtPCS1 recovered c-EC-bimane levels. The level of the c-EC-bimane conjugate was enhanced several-fold in the presence of Cd 2þ ions in the wild type, but not in the PCS-deficient double mutant, consistent with a PCScatalyzed GS-conjugate turnover. Thus AtPCS1 has two cellular functions: mediating both heavy metal tolerance and GS-conjugate degradation.

Hydrophilic interaction liquid chromatography (HILIC) is a popular technique for the separation of polar compounds, which are poorly retained by reversed-phase liquid chromatography. Despite the versatility and the potentiality of this technique, many analysts still feel uncomfortable when approaching it. The HILIC retention mechanism is not completely elucidated and the availability of many different stationary phases may be confusing during method development. Understanding the principles that drive the separation and how they can be influenced by the selection of both stationary phase and chromatographic conditions enhances the range and the quality of possible applications. For this purpose, the review discusses the primary interactions at the basis of HILIC separations and presents an overview of the most common HILIC stationary phases. The effects of the stationary phase type and chromatographic parameters (i.e., organic solvent and salt content, mobile phase pH and column temperature) on each specific interaction are highlighted.