1,425 research outputs found
Green Synthesis of Molecularly Imprinted Polymers for Dispersive Magnetic Solid-Phase Extraction of Erythrosine B Associated with Smartphone Detection in Food Samples
No full textMonitoring synthetic colorants in foods is important due to their potential toxicity and pathogenicity. We propose here a new and simple method for the extraction and determination of erythrosine B (ERT-B) in food samples. A composite of polydopamine-based molecularly imprinted polymers coating magnetic nanoparticles (Fe3O4@PDA@MIP) was synthesized using a green approach and exploited for the magnetic dispersive solid-phase extraction (MDSPE) of ERT-B. Fe3O4@PDA@MIP provides a rapid extraction of ERT-B, exhibiting good reusability and preconcentration ability. Moreover, the MIP showed a relatively good imprinting factor (3.0 ± 0.05), demonstrating excellent selectivity against patent blue (an interfering dye) and other food matrix components. The proposed MDSPE was coupled to colorimetric smartphone-based detection that allowed us to obtain similar performances of UV–Vis spectroscopy detection. The smartphone-based optical detection facilitated the determination of ERT-B in the 0.5–10 mg/L range, with a limit of detection of 0.04 mg/L. The developed method was successfully employed to determine ERT-B in food samples (juice, candy, and candied cherries) with good recovery values (82–97%)
Standard CGIF interoperability in Amine
No full textThe adoption of standard CGIF by CG tools will enable interoperability between them to be achieved, and in turn lead to the interoperability between CG tools and other tools. The integration of ISO Common Logic’s standard CGIF notation in the Amine platform is presented. It also describes the first steps towards full interoperability between the Amine CG tool (through its Synergy component) and CharGer, a representative CG tool that supports similar interoperability and for process (or ‘active’) knowledge as well as declarative knowledge. N-adic relations are addressed as well as semantic compatibility across the two tools. The work remarks on the successes achieved, highlighting certain issues along the way, and offering a real impetus to achieve interoperability.</p
Study on Molecularly Imprinted Polymers Obtained Sonochemically for the Determination of Aflatoxins in Food
No full textAflatoxins (AFs) are fungi secondary metabolites produced by the Aspergillus family. These compounds can enter the food chain through food contamination, representing a risk to human health. Commercial immunoaffinity columns are widely used for the extraction and cleanup of AFs from food samples; however, their high cost and large solvent consumption create a need for alternative strategies. In this work, an alternative strategy for producing molecularly imprinted polymers (MIPs) was proposed to extract aflatoxins AFB1, AFB2, AFG1, and AFG2 from complex food samples, using liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS). The MIPs were synthesized via a low-cost and rapid (5 min) sonochemical free-radical polymerization, using 1-hydroxy-2-naphthoic acid as a dummy template. MIPs-based solid phase extraction performance was tested on 17 dietary supplements (vegetables, fruits, and cereals), obtaining appreciable recovery rates (65–90%) and good reproducibility (RSD ≤ 6%, n = 3); the selectivity towards other mycotoxins was proved and the data obtained compared with commercial immunoaffinity columns. The proposed strategy can be considered an alternative affordable approach to the classical immunoaffinity columns, since it is more selective and better performing
Theoretical effect of concentration, circulation rate, stages, pressure and temperature of single amine and amine mixture solvents on gas sweetening performance
No full textAbstractThis simulation experiment performed by Aspen Hysys is about theoretical investigation of gas sweetening performance of single amine solvents MEA1, MDEA2, DEA3, DGA4, DIPA5 and mixed amine solvents DGA–MEA, DEA–MDEA and SULFOLANE6–MDEA. Sweet gas having very high percentage of methane is produced by MEA (95.36%), DGA–MEA (95.37%), DEA–MDEA (95.51%) and SULFOLANE–MDEA (95.10%) and DGA (93.76%) shows lowest performance. DGA, SULFOLANE–MDEA, MDEA remove H2S at a lower circulation rate and DEA, DIPA need higher but satisfactory circulation rate. Increasing stage number shows positive effect on DEA, DIPA and SULFOLANE–MDEA. Pressure change has no significant effect. Temperature increase and methane percentage are negatively correlated for all solvents (except low circulating DIPA). With temperature increase H2S composition increases for DEA–MDEA, DGA–MEA; CO2 increases for DEA–MDEA, DGA–MEA and high circulating SULFOLANE–MDEA
Electrochemical CO<sub>2</sub> capture can finally compete with amine-based capture
No full textElectrochemical CO2 capture is promising for closing the carbon cycle but needs technological advances. In a recent issue of Nature Energy, a novel chemistry for electrochemical CO2 capture is presented, demonstrating low energy consumption and high purity with virtually no degradation. This finally allows competition with amine-based capture technology.reen Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.ChemE/Transport PhenomenaLarge Scale Energy Storag
Synthesis of Chiral Amines via a Bi-Enzymatic Cascade Using an Ene-Reductase and Amine Dehydrogenase
No full textAccess to chiral amines with more than one stereocentre remains challenging, although an increasing number of methods are emerging. Here we developed a proof-of-concept bi-enzymatic cascade, consisting of an ene reductase and amine dehydrogenase (AmDH), to afford chiral diastereomerically enriched amines in one pot. The asymmetric reduction of unsaturated ketones and aldehydes by ene reductases from the Old Yellow Enzyme family (OYE) was adapted to reaction conditions for the reductive amination by amine dehydrogenases. By studying the substrate profiles of both reported biocatalysts, thirteen unsaturated carbonyl substrates were assayed against the best duo OYE/AmDH. Low (5 %) to high (97 %) conversion rates were obtained with enantiomeric and diastereomeric excess of up to 99 %. We expect our established bi-enzymatic cascade to allow access to chiral amines with both high enantiomeric and diastereomeric excess from varying alkene substrates depending on the combination of enzymes.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.BT/Biocatalysi
Author Correction: Coupling electrochemical CO<sub>2</sub> conversion with CO<sub>2</sub> capture (Nature Catalysis, (2021), 4, 11, (952-958), 10.1038/s41929-021-00699-7)
No full textIn the version of this article, there were errors in Fig. 2a and d. In Fig. 2a, we have changed Cu2+ to Cu(0) in the revised version. While the two references cited in our paper used Cu2+ in their schematics,1,2 we believe that Cu(0) is the correct representation for the electrochemically mediated amine regeneration (EMAR)3. To be clear, the Cu metal anode is oxidized into cupric ions. The cupric ions then bind to the carbamate and displace the CO2 and form a copper–amine complex. The copper–amine complex is then reduced at the cathode where Cu metal is plated out. In Fig. 2d, we have changed the polarity of the cathode and anode in the revised version. A proton is released at the anode, while a hydroxide is released at the cathode. We have also simplified the quinone/hydroquinone chemistry in the revised version to be consistent with proton and hydroxide stoichiometry. The original and revised Fig. 2 images are shown below. The changes have been made to the html and PDF versions of the article.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public. Author correction to DOI 10.1038/s41929-021-00699-7ChemE/Transport Phenomen
De invloed van enkele variabelen op een epoxy-amine tankcoating
No full textBestudeerd werd de invloed van een monofunctionele epoxyverbinding en een oplosmiddelsamenstelling als variabelen op een epoxy-amine tankcoating met behulp van differentiale thermo-analyse , viscositeits- en oppervlaktehardheidsmetingen. Aansluitend hierop is de bestendigheid tegen chemicaliën via diffusiemetingen bepaald. Eveneens werd de invloed bestudeerd die toevoeging van vrije hoeveelheden diëthyleentriamine aan produktiepartijen van amine-adducten op de eindtoestand van de coating heeft.Applied SciencesPolymeerchemi
The first example of multiple oxidation reactions of η6-alkylated aniline-η5-cyclopentadienyliron complexes.
No full textA unique synthetic route to cyclopentadienyliron complexes of functionalized nitrobenzene has been developed via the successive oxidation of the amine and the alkyl groups of their corresponding aniline complexes. Nucleophilic aromatic substitution reactions of the nitroarene complexes with a number of nucleophiles gave rise to monoiron and diiron complexes with various alkyl and keto substituents
Generalized Discrete Events for Accurate Modeling and Simulation of Logic Gates Maamar El Amine Hamri, Norbert Giambiasi, Aziz Naamane
No full textNational audienceno abstrac
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