In this study, multivariate methodologies were applied in the optimization of a dispersive liquid-liquid microextraction (DLLME) method, aiming at the determination of Cu and Mn in coconut water samples by flame atomic absorption spectrometry. Some extractors (chloroform and CCl), dispersants (ethanol, methanol and acetonitrile) and complexing agents (5-Br-PADAP and Dithzone) were previously tested in the extraction. A mixture design was used to optimize the component proportions formed by chloroform (10%), acetonitrile (76%), and 0.020% 5-Br-PADAP solution (14%). Doehlert design optimized the variables pH, NaCl, and buffer amounts for the extraction of both metals. The following analytical characteristics, respectively for Cu and Mn, were accessed: limit of quantification (4.83 and 3.32 µg L), enrichment factors (11 and 8 fold), and precision (6.6 and 6.0% RSD, n = 10). Addition/recovery tests of the analytes allowed to find values in the range of 96.5-120% for Cu and 99-107% for Mn.
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http://dx.doi.org/10.1016/j.foodchem.2021.130473 | DOI Listing |
Nat Mater
January 2025
Max Planck Institute for Chemical Physics of Solids, Dresden, Germany.
High thermoelectric performance is generally achieved by synergistically optimizing two or even three of the contradictorily coupled thermoelectric parameters. Here we demonstrate magneto-thermoelectric correlation as a strategy to achieve simultaneous gain in an enhanced Seebeck coefficient and reduced thermal conductivity in topological materials. We report a large magneto-Seebeck effect and high magneto-thermoelectric figure of merit of 1.
View Article and Find Full Text PDFNat Commun
January 2025
School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, China.
Thin-film composite polyamide (TFC PA) membranes hold promise for energy-efficient liquid separation, but achieving high permeance and precise separation membrane via a facile approach that is compatible with present manufacturing line remains a great challenge. Herein, we demonstrate the use of lignin alkali (LA) derived from waste of paper pulp as an aqueous phase additive to regulate interfacial polymerization (IP) process for achieving high performance nanofiltration (NF) membrane. Various characterizations and molecular dynamics simulations revealed that LA can promote the diffusion and partition of aqueous phase monomer piperazine (PIP) molecules into organic phase and their uniform dispersion on substrate, accelerating the IP reaction and promoting greater interfacial instabilities, thus endowing formation of TFC NF membrane with an ultrathin, highly cross-linked, and crumpled PA layer.
View Article and Find Full Text PDFJ Food Drug Anal
December 2024
Department of Medical Laboratory Science and Biotechnology, Kaohsiung Medical University, Kaohsiung, Taiwan.
This study introduces an innovative bio-based sorbent bead crafted by integrating chitosan (CS) biopolymers, Fe(NO3)3 and polydopamine nanoparticles (PDA NPs) via glutaraldehyde crosslinking. The primary focus of this study was the concurrent separation of diverse tetracycline antibiotics (TCs), followed by rigorous reversed-phase liquid chromatography analysis. The fabricated CS/Fe@PDA sorbent beads were comprehensively characterized using scanning electron microscopy and energy-dispersive X-ray spectroscopy, revealing a surface rich in active carbon (C), nitrogen (N), and oxygen (O) moieties.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China.
Carbon-supported Pt-based catalysts are the most effective catalysts for direct methanol fuel cells (DMFCs). However, challenges such as high Pt loading, cost, and susceptibility to CO poisoning severely hinder the development of DMFCs. In this paper, CoFeO@polymer@ZIF-67 is prepared successfully through sequential solution polymerization and in situ growth with modified CoFeO as the core.
View Article and Find Full Text PDFChempluschem
January 2025
Université de Tours: Universite de Tours, Department of chemistry, 1 JARDIN MONTAIGNE 37300 JOUE LES TOURS, 37300, JOUE LES TOURS, FRANCE.
In this paper, microporous Zn-based zeolitic imidazolate framework with the sodalite cage structure (SOD-ZIF-8) was synthesized by the solvothermal method. Powder X-ray diffraction (PXRD), scanning electron microscopy (SEM) and N2 adsorption were employed to characterize the synthesized material. An ultra-sensitive electrochemical sensor based on highly dispersed bimetallic Ni-Pt nanoparticles immobilized on zeolitic metal-organic framework ZIF-8 for dopamine quantification is introduced for the first time.
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