查看更多>>摘要：? 2022This study focused on developing a set of quality evaluation methods that can reflect the multi-levels and multi-characteristics of traditional Chinese medicine (TCM). Taking licorice (Glycyrrhiza glabra L.) as the method development sample, the feasibility of multi-markers assay by monolinear method (MAML) was explored through the standard curve relationship among active components for the first time. Using glycyrrhizic acid as measurement marker, MAML can simultaneously quantify five components of licorice, including isoliquiritigenin, isoliquiritin apioside, liquiritigenin, liquiritin and liquiritin apioside. Comparing MAML and quantitative analysis of multi-components by single-marker (QAMS) to the external standard method (ESM) respectively, it was found that there was no significant difference in the content of components that were calculated by MAML and ESM (the relative error (RE) was generally less than 2.00%). However, the RE of the component content calculated by QAMS fluctuated greatly, indicating that the MAML was more accurate than QAMS. In addition, UV and THz quantum fingerprints were initiated by the interval erasure method. Taking the systematically quantified fingerprint method as the core, a “Trinity” fingerprint quality evaluation system based on HPLC, UV and THz was developed. The system successfully distinguished the quality differences of licorice samples from 13 producing areas and two ecological models by the comprehensive evaluation results. Simultaneously, the quality information of licorice at different technical levels was revealed. Finally, bivariate correlation analysis was used to examine the linkage between UV/HPLC and antioxidant spectrum efficacy, and the two-dimensional activity spectrum of licorice was provided. It may furnish a more thorough and objective analytical technique for licorice and even other TCMs in chemical fingerprint features, chemical bond vibration characteristics and biological activity information.
查看更多>>摘要：? 2022 Elsevier B.V.The separation of p-xylene (PX) and m-xylene (MX) isomers with near boiling points is a worldwide problem. The metal-organic framework material is an ideal stationary phase for chromatographic separation because of its high porosity, homogeneous pore diameter and good chemical stability. In this paper, a simulated moving bed (SMB) chromatography system with MIL-53(Fe) as the stationary phase and petroleum ether-dichloromethane as the mobile phase was designed to separate PX and MX at ambient temperature. Firstly, according to the elution curves of a single column, nonlinear competitive Langmuir adsorption isotherm equation was confirmed by equilibrium dispersive chromatography model. Then, the SMB separation zone was determined based on triangle theory, and the SMB operating conditions were optimized. Finally, the purity, recovery and productivity of PX reached 100.0%, 99.1% and 93.1 g/L/h, respectively; the purity, recovery and productivity of MX reached 96.4%, 100.0% and 23.5 g/L/h, respectively; the solvent consumption was 0.42 L/g.
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Elsevier