Search results for " Phase"

Application potential of dummy molecularly imprinted polymers as solid-phase extraction sorbents for determination of low-mass polybrominated dipheny…

2019

Abstract Despite the introduction of restrictive regulations in the USA and the European Union, polybrominated diphenyl ethers (PBDEs) are still found in various types of environmental and biological samples at significant concentration levels. The presence of these persistent organic pollutants in the environment raises important issues because of their negative impact on immunological and neurological systems, and on the hormonal balances in living organisms. From the analytical point of view, the final determination of PBDEs would entail substantial challenges, because it would necessitate conducting the pre-concentration of analytes, or sample clean up. The aim of the present study is t…

Assessing drugs of abuse distribution in Turia River based on geographic information system and liquid chromatography mass spectrometry

2017

Drugs of abuse are continuously discharged into wastewaters as part of their elimination process. Pollution at very low concentrations appears to be broad in environmental compartments near populated areas. A total of 42 drugs of abuse and metabolites were analysed in surface water samples collected in 2012 and 2013 by solid phase extraction and liquid chromatography coupled to mass spectrometry. Analytical results of target compounds were georeferenced and integrated into a geographical information systems (GIS). Ecotoxicological risk of drugs of abuse detected in the Turia River was evaluated in this study by calculating risk quotient (RQ). In 2012, 6 compounds were detected in a total of…

Phytoscreening as an efficient tool to delineate chlorinated solvent sources at a chlor-alkali facility

2017

Chlorinated ethenes (CE) are among the most common volatile organic compounds (VOC) that contaminate groundwater, currently representing a major source of pollution worldwide. Phytoscreening has been developed and employed through different applications at numerous sites, where it was generally useful for detection of subsurface chlorinated solvents. We aimed at delineating subsurface CE contamination at a chlor-alkali facility using tree core data that we compared with soil data. For this investigation a total of 170 trees from experimental zones was sampled and analyzed for perchloroethene (PCE) and trichloroethene (TCE) concentrations, measured by solid phase microextraction gas chromato…

Perfluoroalkyl substance contamination of the Llobregat River ecosystem (Mediterranean area, NE Spain).

2014

The occurrence and sources of 21 perfluoroalkyl substances (PFASs: C4-C14, C16, C18 carboxylate, C4, C6-C8 and C10 sulfonates and C8 sulfonamide) were determined in water, sediment, and biota of the Llobregat River basin (NE Spain). Analytes were extracted by solid phase extraction (SPE) and determined by liquid chromatography triple quadrupole mass spectrometer (LC-QqQ-MS). All samples were contaminated with at least one PFAS, being the most frequently found perfluorobutanoate (PFBA), perfluorooctanoate (PFOA) and perfluorooctane sulfonate (L-PFOS). In general, mean PFAS concentrations measured in sediments (0.01-3.67 ng g(-1)) and biota (0.79-431 μg kg(-1)) samples were higher than those …

Composites poly-lactic acid - hydroxyapatite scaffolds prepared via Thermally Induced Phase Separation

2013

Development of pipette tip-based poly(methacrylic acid-co-ethylene glycol dimethacrylate) monolith for the extraction of drugs of abuse from oral flu…

2019

Abstract In this work, a monolithic polymer based on poly(methacrylic acid-co-ethylene glycol dimethacrylate) (MAA-co-EDMA) was prepared inside 200 μL pipette tips for the extraction of drug of abuse from oral fluid samples. After an appropriate surface tip modification, several polymerization mixtures with different monomer/cross-linker ratios, and percentage of porogen were studied. The most appropriate monolith to easily flow organic solvents and oral fluid samples was prepared with a MAA/EDMA ratio of 8:92 wt/wt and dodecanol containing 10 wt% toluene, as porogenic solvent. Parameters affecting the extraction procedure were evaluated and the monolith was characterized in terms of bindin…

USO DI TECNICHE AVANZATE PER LA OTTIMIZZAZIONE STRUTTURALE E FUNZIONALE DI SCAFFOLD COMPOSITI POLIMERO-CARICA INORGANICA PER LA RIGENERAZIONE OSSEA.

2020

AN EXPERIMENTAL APPARATUS TO CHARACTERIZE PHASE SEPARATION IN POLYMER SOLUTIONS

2013

Measurement of cloud point temperature in polymer solutions

2013

Surface molecularly imprinted silica for selective solid-phase extraction of biochanin A, daidzein and genistein from urine samples

2015

Selective molecularly imprinted silica polymer (SiO2MIP) for extraction of biochanin A, daidzein and genistein was synthesized using the surface molecular imprinting technique with the silica gel as a support. Biochanin A (BCA) was used as a template, 3-aminopropyltriethoxysilane (APTES) as a functional monomer, and tetraethoxysilicane (TEOS) as a cross-linker. Non-imprinted polymer with the sol–gel process (SiO2NIP) was also prepared for comparison. The synthesized polymers were characterized by Fourier transform infrared spectrometry (FTIR), scanning electron microscopy (SEM) and a standard Brunauer-Emett-Teller (BET) and Barret–Joyner–Halenda (BJH) analysis. The obtained results indicate…