Environmentally friendly analysis of emerging contaminants by pressurized hot water extraction-stir bar sorptive extraction-derivatization and gas chromatography-mass spectrometry

This work describes the development, optimiza- tion, and validation of a new method for the simultaneous determination of a wide range of pharmaceuticals (beta- blockers, lipid regulators ... ) and personal care products (fragrances, UV filters, phthalates ... ) in both aqueous and solid environmental matrices. Target compounds were extracted from sediments using pressurized hot water ex- traction followed by stir bar sorptive extraction. The first stage was performed at 1,500 psi during three static extrac- tion cycles of 5 min each after optimizing the extraction temperature (50 – 150 °C) and addition of organic modifiers (% methanol) to water, the extraction solvent. Next, aqueous extracts and water samples were processed using polydime- thylsiloxane bars. Several parameters were optimized for this technique, including extraction and desorption time, ionic strength, presence of organic modifiers, and pH. Fi- nally, analytes were extracted from the bars by ultrasonic irradiation using a reduced amount of solvent (0.2 mL) prior to derivatization and gas chromatography – mass spectrome- try analysis. The optimized protocol uses minimal amounts of organic solvents (<10 mL/sample) and time ( ≈ 8 h/sam- ple) compared to previous ex isting methodologies. Low standard deviation (usually below 10 %) and limits of de- tection (sub-ppb) vouch for the applicability of the method- ology for the analysis of target compounds at trace levels. Once developed, the method was applied to determin

Sunscreens in Coastal Ecosystems. Chapter:Fate and behavior of uv filters in the marine environment

UV filters are released into the coastal areas by a combination of different sources, including wastewater discharges and direct input related to recreational activities. To fully understand the risks associated with the occurrence of UV filters in the marine environment, better knowledge on their distribution and environmental behavior is required. So far, concentrations of several parts per trillion have been reported in different marine settings from touristic areas. Temporal variations in levels for organic UV filters have been associated with beach use, whereas for inorganic UV filters a preferential accumulation in the surface microlayer was observed. The latter are often released as nanoparticles, which have a tendency to form aggregates and precipitate. Due to their relatively high hydrophobicity, organic UV filters can also end up in the seafloor. Although sediments are not so frequently monitored at seawater, higher UV-filter levels (a few ng g−1) are usually found. Regarding their reactivity in the marine environment, the elucidation of degradation pathways and kinetics is still mostly unknown, although photochemical degradation seems to be a major transformation route for most organic UV filters. Regarding inorganic UV filters, their nanoparticles are subjected to weathering or aging and have also tendency to generate free radicals such as hydrogen peroxide under solar irradiatio

Environmental Risk Assessment of Sunscreens

22 pagesThe sunscreens are complex products for protecting the skin of UV radiation. These products contain active ingredients organic and inorganic UV filters. The release of some of these components can provoke negative effects to aquatic ecosystems. The UV filters have shown to be present in environmental compartments (freshwater, wastewater, groundwater, seawater, sediment, and sand) and to be ubiquitous, motivated by the use in other applications. To assess the environmental risk of these products implies to know exposure conditions and toxic effects in order to establish the risk quotient. This is calculated as the ratio between predicted environmental concentration (PEC) or measured environmental concentration (MEC) and predicted no-effect concentration (PNEC). The organic compounds that presented higher risk were benzophenone-3, ethylhexyl methoxycinnamate, and 4-methylbenzylidene camphor. Nevertheless, this risk is depending on the location and environmental compartment. The lack of a database concentration of inorganic nanoparticles (TiO2 and ZnO) makes difficult to carry out a realistic assessment of environmental risk, although using modeled data an approach was carried out. The results evidenced that certain risk can be related to the release of these nanomaterials from sunscreens, although a refinement will be necessary to reduce the uncertainties. Finally, some gaps of information have been identified in order to get a more realistic environmental risk assessment. Thus, the toxicity of the mixture of sunscreens compounds under realistic conditions and the improvement of the knowledge of their mode of actions could be the next stepsWe would like to thank to the projects CTM2016-75908-R funding by the Spanish Ministry of Economy, Industry and Competitiveness (MINECO) and FEDER funds and the Junta de Andalucía PAIDI, Excellence Research Group RNM306 for their supportPeer reviewe

In Situ Passive Sampling Techniques for Monitoring Environmental Mixture Exposure

A large number of passive sampler devices have been developed for in situ sensing of polar and nonpolar organic chemicals in the environment. This chapter compiles and analyzes available information on the current progress in quantitation theories and technological improvements. The results show that it is critical to determine sorbent phase-water partition coefficients and sampling rates of target analytes for quantitation with the equilibrium and kinetic sampling strategies. Compared to passive sampling of organic contaminants in air, overlying water and sediment porewater, which has been extensively documented, measurements of organic contaminants in soil and at the air-soil interface have been largely unsuccessful with passive samplers. In addition, the combination of in situ passive sampling devices and bioassays could be a promising tool for directly assessing air and water quality with biological effects