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Headspace solid-phase microextraction-gas chromatography-quadrupole mass spectrometric methodology for the establishment of the volatile composition of Passiflora fruit species

ty10086 提交于 周四, 08/26/2021 - 13:46
Abstract(#br)Dynamic headspace solid-phase microextraction (HS-SPME) followed by thermal desorption gas chromatography-quadrupole mass spectrometry analysis (GC- q MS), was used to investigate the aroma profile of different species of passion fruit samples. The performance of five commercially available SPME fibres: 65 μm polydimethylsiloxane/divinylbenzene, PDMS/DVB; 100 μm polydimethylsiloxane, PDMS; 85 μm polyacrylate, PA; 50/30 μm divinylbenzene/carboxen on polydimethylsiloxane, DVB/CAR/PDMS (StableFlex); and 75 μm carboxen/polydimethylsiloxane, CAR/PDMS; was evaluated and compared.

A new polyethylene glycol fiber prepared by coating porous zinc electrodeposited onto silver for solid-phase microextraction of styrene

ty10086 提交于 周四, 08/26/2021 - 13:45
Abstract(#br)A new polyethylene glycol fiber was developed for solid-phase microextraction (SPME) of styrene by electrodepositing porous Zn film on Ag wire substrate followed by coating with polyethylene glycol sol–gel (Ag/Zn/PEG sol–gel fiber). The scanning electron micrographs of fibers surface revealed a highly porous structure. The extraction property of the developed fiber-to-styrene residue from polystyrene packaged food was investigated by headspace solid-phase microextraction (HS-SPME) and analyzed with a gas chromatograph coupled with flame ionization detection (GC-FID).

Using disposable solid-phase microextraction (SPME) to determine the freely dissolved concentration of polybrominated diphenyl ethers (PBDEs) in sediments

ty10086 提交于 周四, 08/26/2021 - 13:38
Abstract(#br)Polybrominated diphenyl ethers (PBDEs) are brominated flame retardants (BFRs). The ubiquity and persistence of PBDEs in sediment have raised concerns over their environmental fate and ecological risks. Due to strong affinity for sediment organic matter, environmental fate and bioavailability of PBDEs closely depend on their phase distribution. In this study, disposable polydimethylsiloxane (PDMS) fiber was used to derive the freely dissolved concentration ( C free ) of PBDEs in sediment porewater as a measurement of bioavailability.

Concave porosity non-polar beads by a modified microbubble fabrication

ty10086 提交于 周四, 08/26/2021 - 13:36
Abstract(#br)A modified procedure for the production of porous polydimethylsiloxane (PDMS) beads is presented which results in non-polar polymer beads with microscale concavity and therefore an increased surface-area-to-volume ratio. The key modification is the simple addition of a platinum catalyst to the emulsion prior to thermal curing. Elemental analysis of beads indicates the presence of platinum at the center of many of the indentations, which provides insight into the synthetic mechanisms.

Headspace solid-phase microextraction-gas chromatography–mass spectrometry characterization of propolis volatile compounds

ty10086 提交于 周四, 08/26/2021 - 13:35
Abstract(#br)In this study, a novel and efficient method based on headspace solid-phase microextraction (HS-SPME), followed by gas chromatography–mass spectrometry (GC–MS), was developed for the analysis of propolis volatile compounds. The HS-SPME procedure, whose experimental parameters were properly optimized, was carried out using a 100\u003cce:hsp sp=\"0.25\"/\u003eμm polydimethylsiloxane (PDMS) fiber.

Cobalt oxide nanoparticles as a novel high-efficiency fiber coating for solid phase microextraction of benzene, toluene, ethylbenzene and xylene from aqueous solutions

ty10086 提交于 周四, 08/26/2021 - 13:34
Abstract(#br)In this work cobalt oxide nanoparticles were introduced for preparation of a novel solid phase microextraction (SPME) fiber coating. Chemical bath deposition (CBD) technique was used in order for synthesis and immobilization of the Co 3 O 4 nanomaterials on a Pt wire for fabrication of SPME fiber. The prepared cobalt oxide coating was characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis. The fiber was evaluated for the extraction of benzene, toluene, ethylbenzene and xylene (BTEX) in combination with GC–MS.

In situ growth of IRMOF-3 combined with ionic liquids to prepare solid-phase microextraction fibers

ty10086 提交于 周四, 08/26/2021 - 13:34
Abstract(#br)A superior solid-phase microextraction (SPME) fiber-coating material, IRMOF-3@ILs/PDMS, was prepared by the in situ growth of IRMOF-3 onto stainless-steel wires and protection with ionic liquids (ILs) and polydimethylsiloxane (PDMS). The ILs can efficiently prevent the substantial cracking of IRMOF-3 caused by moisture, and a thin PDMS film can protect the IRMOF-3@ILs material to achieve a much better extraction efficiency as well as excellent resistance to high temperature and high humidity.

Determination of phthalate esters in vegetable oils using direct immersion solid-phase microextraction and fast gas chromatography coupled with triple quadrupole mass spectrometry

ty10086 提交于 周四, 08/26/2021 - 13:31
Abstract(#br)Phthalates are a group of synthetic compounds mainly used as plasticizers, which have been classified as endocrine-disrupting chemicals and potential human-cancer causing agents. They can be found in high amounts in foods, deriving mainly from plastic packaging. The analytical determination of these compounds is very challenging since they are ubiquitous. Therefore, minimization of sample manipulation is highly desirable.(#br)The present work exploited the application of a solid-phase microextraction method for the analysis of phthalates in vegetable oil.

Monodisperse microporous carbon nanospheres: An efficient and stable solid phase microextraction coating material

ty10086 提交于 周四, 08/26/2021 - 13:31
Abstract(#br)The monodisperse microporous carbon nanospheres (MMCNSs) were applied in solid phase microextraction for the first time. The MMCNSs-fiber was prepared by sol–gel technique and good repeatability and reproducibility were obtained, due to the excellent monodispersity of the MMCNSs.