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21.
Multiresidue determination of UV filters in water samples by solid‐phase extraction and liquid chromatography with tandem mass spectrometry analysis
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Anna Laura Capriotti Chiara Cavaliere Susy Piovesana Roberto Samperi Serena Stampachiacchiere Salvatore Ventura Aldo Laganà 《Journal of separation science》2014,37(20):2882-2891
UV filters, contained in sunscreens and other cosmetic products, as well as in some plastics and industrial products, are nowadays considered contaminants of emerging concern because their widespread and increasing use has lead to their presence in the environment. Furthermore, some UV filters are suspected to have endocrine disruption activity. In the present work, we developed an analytical method based on liquid chromatography with tandem mass spectrometry for the determination of UV filters in tap and lake waters. Sixteen UV filters were extracted from water samples by solid‐phase extraction employing graphitized carbon black as adsorbent material. Handling 200 mL of water sample, satisfactory recoveries were obtained for almost all the analytes. The limits of detection and quantification of the method were comparable to those reported in other works, and ranged between 0.7–3.5 and 1.9–11.8 ng/L, respectively; however in our case the number of investigated compounds was larger. The major encountered problem in method development was to identify the background contamination sources and reduce their contribution. UV filters were not detected in tap water samples, whereas the analyses conducted on samples collected from three different lakes showed that the swimming areas are most subject to UV filter contamination. 相似文献
22.
QuEChERS sample preparation for the determination of pesticides and other organic residues in environmental matrices: a critical review 总被引:4,自引:0,他引:4
Maria Concetta Bruzzoniti Leonardo Checchini Rosa Maria De Carlo Serena Orlandini Luca Rivoira Massimo Del Bubba 《Analytical and bioanalytical chemistry》2014,406(17):4089-4116
Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) is an extraction and clean-up technique originally developed for recovering pesticide residues from fruits and vegetables. Since its introduction, and until December 2013, about 700 papers have been published using the QuEChERS technique, according to a literature overview carried out using SciFinder, Elsevier SciVerse, and Google search engines. Most of these papers were dedicated to pesticide multiresidue analysis in food matrices, and this topic has been thoroughly reviewed over recent years. The QuEChERS approach is now rapidly developing beyond its original field of application to analytes other than pesticides, and matrices other than food, such as biological fluids and non-edible plants, including Chinese medicinal plants. Recently, the QuEChERS concept has spread to environmental applications by analyzing not only pesticides but also other compounds of environmental concern in soil, sediments, and water. To the best of our knowledge, QuEChERS environmental applications have not been reviewed so far; therefore, in this contribution, after a general discussion on the evolution and changes of the original QuEChERS method, a critical survey of the literature regarding environmental applications of conventional and modified QuEChERS methodology is provided. The overall recoveries obtained with QuEChERS and other extraction approaches (e.g., accelerated solvent extraction, ultrasonic solvent extraction, liquid/solid extraction, and soxhlet extraction) were compared, providing evidence for QuEChERS higher recoveries for various classes of compounds, such as biopesticides, chloroalkanes, phenols, and perfluoroalkyl substances. The role of physicochemical properties of soil (i.e., clay and organic carbon content, as well as cation exchange capacity) and target analytes (i.e., log KOW, water solubility, and vapor pressure) were also evaluated in order to interpret recovery and matrix effect data. 相似文献
23.
Luka
orevi Lorenzo Casimiro Nicola Demitri Massimo Baroncini Serena Silvi Francesca Arcudi Alberto Credi Maurizio Prato 《Angewandte Chemie (International ed. in English)》2021,60(1):313-320
Multi‐functionalization and isomer‐purity of fullerenes are crucial tasks for the development of their chemistry in various fields. In both current main approaches—tether‐directed covalent functionalization and supramolecular masks—the control of regioselectivity requires multi‐step synthetic procedures to prepare the desired tether or mask. Herein, we describe light‐responsive tethers, containing an azobenzene photoswitch and two malonate groups, in the double cyclopropanation of [60]fullerene. The formation of the bis‐adducts and their spectroscopic and photochemical properties, as well as the effect of azobenzene photoswitching on the regiochemistry of the bis‐addition, have been studied. The behavior of the tethers depends on the geometry of the connection between the photoactive core and the malonate moieties. One tether lead to a strikingly different adduct distribution for the E and Z isomers, indicating that the covalent bis‐functionalization of C60 can be controlled by light. 相似文献
24.
Dr. Ileana-Alexandra Pavel Dr. Gerardo Salinas Dr. Maciej Mierzwa Dr. Serena Arnaboldi Patrick Garrigue Prof. Alexander Kuhn 《Chemphyschem》2021,22(13):1321-1325
Numerous artificial micro- and nanomotors, as well as various swimmers have been inspired by living organisms that are able to move in a coordinated manner. Their cooperation has also gained a lot of attention because the resulting clusters are able to adapt to changes in their environment and to perform complex tasks. However, mimicking such a collective behavior remains a challenge. In the present work, magnesium microparticles are used as chemotactic swimmers with pronounced collective features, allowing the gradual formation of macroscopic agglomerates. The formed clusters act like a single swimmer able to follow pH gradients. This dynamic behavior can be used to spot localized corrosion events in a straightforward way. The autonomous docking of the swimmers to the corrosion site leads to the formation of a local protection layer, thus increasing corrosion resistance and triggering partial self-healing. 相似文献
25.
Dramatic Influence of an Anionic Donor on the Oxygen‐Atom Transfer Reactivity of a MnV–Oxo Complex
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Heather M. Neu Dr. Matthew G. Quesne Tzuhsiung Yang Dr. Katharine A. Prokop‐Prigge Prof. Kyle M. Lancaster James Donohoe Prof. Serena DeBeer Dr. Sam P. de Visser Prof. David P. Goldberg 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(45):14584-14588
Addition of an anionic donor to an MnV(O) porphyrinoid complex causes a dramatic increase in 2‐electron oxygen‐atom‐transfer (OAT) chemistry. The 6‐coordinate [MnV(O)(TBP8Cz)(CN)]? was generated from addition of Bu4N+CN? to the 5‐coordinate MnV(O) precursor. The cyanide‐ligated complex was characterized for the first time by Mn K‐edge X‐ray absorption spectroscopy (XAS) and gives Mn?O=1.53 Å, Mn?CN=2.21 Å. In combination with computational studies these distances were shown to correlate with a singlet ground state. Reaction of the CN? complex with thioethers results in OAT to give the corresponding sulfoxide and a 2e?‐reduced MnIII(CN)? complex. Kinetic measurements reveal a dramatic rate enhancement for OAT of approximately 24 000‐fold versus the same reaction for the parent 5‐coordinate complex. An Eyring analysis gives ΔH≠=14 kcal mol?1, ΔS≠=?10 cal mol?1 K?1. Computational studies fully support the structures, spin states, and relative reactivity of the 5‐ and 6‐coordinate MnV(O) complexes. 相似文献
26.
Inherently Chiral Macrocyclic Oligothiophenes: Easily Accessible Electrosensitive Cavities with Outstanding Enantioselection Performances
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Prof. Francesco Sannicolò Prof. Patrizia R. Mussini Prof. Tiziana Benincori Dr. Roberto Cirilli Prof. Sergio Abbate Serena Arnaboldi Simone Casolo Dr. Ettore Castiglioni Prof. Giovanna Longhi Dr. Rocco Martinazzo Dr. Monica Panigati Dr. Marco Pappini Dr. Elsa Quartapelle Procopio Dr. Simona Rizzo 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(47):15298-15302
Linear conjugated oligothiophenes of variable length and different substitution pattern are ubiquitous in technologically advanced optoelectronic devices, though limitations in application derive from insolubility, scarce processability and chain‐end effects. This study describes an easy access to chiral cyclic oligothiophenes constituted by 12 and 18 fully conjugated thiophene units. Chemical oxidation of an “inherently chiral” sexithiophene monomer, synthesized in two steps from commercially available materials, induces the formation of an elliptical dimer and a triangular trimer endowed with electrosensitive cavities of different tunable sizes. Combination of chirality with electroactivity makes these molecules unique in the current oligothiophenes literature. These macrocycles, which are stable and soluble in most organic solvents, show outstanding chiroptical properties, high circularly polarized luminescence effects and an exceptional enantiorecognition ability. 相似文献
27.
28.
Gilbert Mercieca Sara Odoardi Serena Mestria Marisa Cassar Sabina Strano‐Rossi 《Journal of separation science》2020,43(14):2858-2868
The constant emergence of new psychoactive substances is a challenge to clinical and forensic toxicologists who need to constantly update analytical techniques to detect them. A large portion of these substances are synthetic cannabinoids. The aim of this study was to develop a rapid and simple method for the determination of synthetic cannabinoids and their metabolites in urine and blood using gas chromatography–mass spectrometry. The method involves an ultrasound‐assisted dispersive liquid–liquid microextraction that implies a rapid procedure, giving excellent extraction efficiencies with minimal use of toxic solvents. This is followed by silylation and analysis with gas chromatography–mass spectrometry. The chromatographic method allows for the separation and identification of 29 selected synthetic cannabinoids and some metabolites. The method was validated on urine and blood samples with the ability to detect and quantify all analytes with satisfactory limits of detection (from 1 to 5 ng/mL), limits of quantification (5 ng/mL), and selectivity and linearity (in the range of 5–200 ng/mL). The developed assay is highly applicable to laboratories with limited instrumental availability, due to the use of efficient and low‐cost sample preparation and instrumental equipment. The latter may contribute to enhance the detection of new psychoactive substances in clinical and forensic toxicology laboratories. 相似文献
29.
30.
Ismael Otri Serena Medaglia Elena Aznar Flix Sancenn Ramn Martínez-Mez 《Molecules (Basel, Switzerland)》2022,27(3)
Mesoporous silica nanoparticles loaded with rhodamine B and capped with curcumin are used for the selective and sensitive fluorogenic detection of human serum albumin (HSA). The sensing mesoporous silica nanoparticles are loaded with rhodamine B, decorated with aminopropyl moieties and capped with curcumin. The nanoparticles selectively release the rhodamine B cargo in the presence of HSA. A limit of detection for HSA of 0.1 mg/mL in PBS (pH 7.4)-acetonitrile 95:5 v/v was found, and the sensing nanoparticles were used to detect HSA in spiked synthetic urine samples. 相似文献