QUALITY ASSESSMENT OF GINSENG BY CHEMICAL FUZZY PATTERN RECOGNITION

A new method of assessing ginseng and screening its bioactive constituents by fuzzy pattern recognition has been proposed.

HPLC fingerprint of Nauclea officinalis stems in different harvesting period

Objective:To establish HPLC fingerprint of Nauclea officinalis stems in different harvesting periods,and analyze the effect of harvest time on the quality of the medicinal materials by combining with chemical pattern recognition.Methods:The analysis was performed on Sun Fire-C18(150 mm×4.6 mm,5μm)column.The mobile phase consisted of acetonitrile-0.1%phosphoric acid solution(gradient elution)at a flow rate of 1.0 mL/min.Results:The HPLC fingerprint of Nauclea officinalis stems was established and 12 common peaks were determined,and 3 chromatographic peaks were identified by comparison with the mixed references.There were some differences in the quality of Nauclea officinalis in different harvesting periods.The OPLS-DA analysis successfully predicted four main markers of quality difference.Conclusion:The established HPLC fingerprint could reflect the composition characteristics of Nauclea officinalis stems in different harvesting period,and the main markers that influence the composition difference of the stems could be used as key indicators for the quality control.

Chemical profiling and rapid discrimination of Blumea riparia and Blumea megacephala by UPLC-Q-Exactive-MS/MS and HPLC

Objective:To rapidly identify the two morphologies and chemical properties of similar herbal medicines,Blumea riparia and B.megacephala as the basis for chemical constituent analysis.Methods:UPLC-Q-Exactive-MS/MS was utilized for profiling and identification of the constituents in B.riparia and B.megacephala.Chemical pattern recognition(CPR)was further used to compare and distinguish the two herbs and to identify their potential characteristic markers.Then,an HPLC method was established for quality evaluation.Results:A total of 93 constituents are identified,including 54 phenolic acids,35 flavonoids,two saccharides,one phenolic acid glycoside,and one other constituent,of which 67 were identified in B.riparia and B.megacephala for the first time.CPR indicates that B.riparia and B.megacephala samples can be distinguished from each other based on the LC–MS data.The isochlorogenic acid A to cryptochlorogenic acid peak area ratio calculated from the HPLC chromatograms was proposed as a differentiation index for distinguishing and quality control of B.riparia and B.megacephala.Conclusion:This study demonstrates significant differences between B.riparia and B.megacephala in terms of chemical composition.The results provide a rapid and simple strategy for the comparison and evaluation of the quality of B.riparia and B.megacephala.

Operando-reconstructed polyatomic ion layers boost the activity and stability of industrial current–density water splitting

Metal–organic frameworks have garnered attention as highly efficient pre-electrocatalysts for the oxygen evolution reaction(OER).Current structure–activity relationships primarily rely on the assumption that the complete dissolution of organic ligands occurs during electrocatalysis.Herein,modeling based on NiFe Prussian blue analogs(NiFe-PBAs)show that cyanide ligands leach from the matrix and subsequently oxidize to corresponding inorganic ions(ammonium and carbonate)that re-adsorb onto the surface of NiFe OOH during the OER process.Interestingly,the surface-adsorbed inorganic ions induce the OER reaction of NiFe OOH to switch from the adsorbate evolution to the lattice-oxygen–mediated mechanism,thus contributing to the high activity.In addition,this reconstructed inorganic ion layer acting as a versatile protective layer can prevent the dissolution of metal sites to maintain contact between catalytic sites and reactive ions,thus breaking the activity–stability trade-off.Consequently,our constructed NiFePBAs exhibit excellent durability for 1250 h with an ultralow overpotential of 253 mV at 100 mA cm2.The scale-up NiFe-PBAs operated with a low energy consumption of4.18 kWh m3 H2 in industrial water electrolysis equipment.The economic analysis of the entire life cycle demonstrates that this green hydrogen production is priced at US$2.59 kg^(-1)H_(2),meeting global targets(<US$2.5 kg^(-1)H_(2)).