We demonstrate a facile and versatile method to grow Ru particles uniformly on pristine few-layer graphene (FLG) in supercritical diethylamine. In particular, a large number of Ru subnanometer clusters less than 1.0 nm were observed. The particle size can be tuned by manipulating the loading content of Ru and controlling the reaction temperature. The resulting Ru/FLG showed remarkably high activity, selectivity, and reusability towards the hydrogenation of levulinic acid to γ-valerolactone. This method is flexible, and can be extended to the synthesis of a variety of other ultrafine metal particles supported on FLG.
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http://dx.doi.org/10.1088/1361-6528/aa9b70 | DOI Listing |
J Chromatogr A
November 2024
Institute of Medicinal Biotechnology, Peking Union Medical College & Chinese Academy of Medical Sciences, Tian Tan Xi Li No.2, Beijing 100050, PR China. Electronic address:
Simultaneous separation of compounds with multiple chiral centers and highly similar structures presents significant challenges. This study developed a novel supercritical fluid chromatography (SFC) method with reduced organic solvent consumption and robust separation capabilities to address these challenges. The method was applied to simultaneously achieve enantioselective, diastereoselective, and achiral separation of palonosetron hydrochloride and its six impurities.
View Article and Find Full Text PDFAnal Chem
July 2024
Institut de Chimie Organique et Analytique, CNRS UMR 7311, Université d'Orleans, rue de Chartres, CEDEX 2 45067 Orléans, France.
J Chromatogr A
February 2024
Engineering Research Center of Pharmaceutical Process Chemistry, Ministry of Education, School of Pharmacy, East China University of Science and Technology, Shanghai 200237, PR China; Key Lab of Separation Science for Analytical Chemistry, Key Lab of Natural Medicine, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, PR China.
In the last decade, the separation application based on aromatic stationary phases has been demonstrated in supercritical fluid chromatography (SFC). In this paper, four aromatic stationary phases involving aniline (S-aniline), 1-aminonaphthalene (S-1-ami-naph), 1-aminoanthracene (S-1-ami-anth) and 1-aminopyrene (S-1-ami-py) were synthesized based on full porous particles (FPP) silica, which were not end-capped for providing extra electrostatic interaction. Retention mechanism of these phases in SFC was investigated using a linear solvation energy relationship (LSER) model.
View Article and Find Full Text PDFJ Chromatogr Sci
May 2024
Daicel Chiral Technologies, 1475 Dunwoody Dr. Suite 310, West Chester, PA 19380, USA.
An optimized method employing chiral supercritical fluid chromatography with diode array UV-VIS detection has been developed for the quantitative analysis of nicotine and nornicotine enantiomer distributions. The method parameters that were optimized included: column type (stationary phases, Chiralpak IG-3), column temperature (40°C), modifier types and concentration (isopropyl alcohol, 10%), additive types and concentrations (diethylamine, 0.2%), elution times (<6 min, flow rate 3 mL/min) and resolution factor (>1.
View Article and Find Full Text PDFJ Chromatogr A
August 2023
Engineering Research Center of Pharmaceutical Process Chemistry, Ministry of Education, School of Pharmacy, East China University of Science and Technology, Shanghai 200237, PR China. Electronic address:
The present paper illustrates the versatility of the supercritical fluid chromatography (SFC) since, for the first time, four spirooxindole alkaloids (SOAs) including two pairs of isomers were separated by using two types of reversed-phase/ ion chromatography (RP/IC) mixed-mode stationary phases. Two mixed-mode stationary phases (C8SAX and C8SCX) was simultaneously provided dispersive and electrostatic interactions, which were suitable for the separation of such alkaloids. This study tried to provide an in-depth understanding of the SFC separation mechanism of the mixed-mode stationary phase through investigation of the impact of changes in mobile phase composition on alkaloids' retention behavior.
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