We demonstrate here that the electrode kinetics of an electrochemical detector contributes greatly to the resolution of the analyte bands in microchip electrophoresis systems with amperometric detection. The separation performance in terms of resolution and theoretical plate number can be improved and tailored by selecting or modifying the working electrode and/or by controlling the detection potential. Such improvements in the separation performance reflect the influence of the heterogeneous electron-transfer rate of electroactive analytes upon the post-channel band broadening, as illustrated for catechol and hydrazine compounds. The electrode kinetics thus has a profound effect not only on the sensitivity of electrochemical detectors but on the separation efficiency and the overall performance of microchip electrochemistry systems.
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http://dx.doi.org/10.1002/elps.200800845 | DOI Listing |
Talanta
January 2025
The School of Material Science and Chemical Engineering, Harbin University of Science and Technology, Harbin, 150040, PR China.
Epinephrine (Ep) is an important neurotransmitter, which plays an important role in the nervous system and glycogen metabolism of living organisms. Hence, a novel NCQDs/FeCoFe-PBA composite with FeCoFe-Prussian blue analogues (PBA) as the core and nitrogen-doped carbon quantum dots (NCQDs) as the shell was constructed by a one-pot hydrothermal method, and it was used for the efficient detection of Ep. As a good electroactive material, NCQDs in the composite not only improved the weak conductivity of FeCoFe-PBA, but also limited the self-aggregation of FeCoFe-PBA, and formed a uniform shell on FeCoFe-PBA.
View Article and Find Full Text PDFEnviron Res
December 2024
Guangxi Colleges and Universities Key Laboratory of Environmental-friendly Materials and Ecological Remediation, Guangxi Key Laboratory of Advanced Structural Materials and Carbon Neutralization, School of Materials and Environment, Guangxi Minzu University, Nanning, 530006, China. Electronic address:
Water pollution caused by antibiotics is considered a major and growing issue. To address this challenge, high-performance copper vanadate-based biochar (CuVO/BC) nanocomposite photocatalysts were prepared to develop an efficient visible light-driven photocatalytic system for the remediation of tetracycline (TC) contaminated water. The effects of photocatalyst mass, solution pH, pollutant concentration, and common anions on the TC degradation were investigated in detail.
View Article and Find Full Text PDFJ Colloid Interface Sci
December 2024
College of Chemical Engineering and Materials Science, Tianjin University of Science and Technology, Tianjin 300350, PR China; Tianjin Key Laboratory of Multiplexed Identification for Port Hazardous Chemicals, Tianjin 300457, PR China. Electronic address:
A novel porphyrin based covalent organic frameworks (Por-BABN-COF) has been successfully constructed via self-polycondensation of a newly developed AB porphyrin building block possessing two amino groups and two neopentyl acetal at the meso-position. Por-BABN-COF was employed as a heterogeneous photocatalyst for the selective oxidation of sulfides and CO cycloaddition due to its superior light absorption capacity, strong crystallinity and high stability. The high conversion, good selectivity and excellent reusability indicate Por-BABN-COF is a promising photocatalyst for both reactions.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
Nanjing University of Science and Technology, nanoscience and nanotechnology, Xiaolin wei 200, 210094, Nanjing, CHINA.
Suppressing over-oxidation is a crucial challenge for various chemical intermediate synthesis in heterogeneous catalysis. The distribution of oxidative species and the substrate coverage, governed by the direction of electron transfer, are believed to influence the oxidation extent. In this study, we present an experimental realization of surface coverage modulation on a photoelectrode using a photo-induced charge activation method.
View Article and Find Full Text PDFJ Am Chem Soc
December 2024
Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States.
Designing catalysts with well-defined active sites with chemical functionality responsive to visible light has significant potential for overcoming scaling relations limiting chemical reactions over heterogeneous catalyst surfaces. Visible light can be leveraged to facilitate the removal of strongly bound species from well-defined single cationic sites (Rh) under mild conditions (323 K) when they are incorporated within a photoactive perovskite oxide (Rh-doped SrTiO). CO, a key intermediate in many chemistries, forms stable geminal dicarbonyl Rh complexes (Rh(CO)), that could act as site blockers or poisons during a catalytic cycle.
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