scholarly journals Flow-dependent separation selectivity for organic molecules on metal–organic frameworks containing adsorbents

2016 ◽  
Vol 52 (30) ◽  
pp. 5301-5304 ◽  
Author(s):  
Anton Peristyy ◽  
Pavel N. Nesterenko ◽  
Anita Das ◽  
Deanna M. D'Alessandro ◽  
Emily F. Hilder ◽  
...  

A new effect was discovered which allows changes of selectivity by variation of the mobile phase flow rate.

Processes ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 91 ◽  
Author(s):  
Pian Zhang ◽  
Kang-Ling Zhu ◽  
Jun Zhang ◽  
Yan Li ◽  
Heng Zhang ◽  
...  

In order to obtain high-purity flavonoid products, the extracts from mulberry leaves were separated and purified via high-speed counter-current chromatography (HSCCC). Moreover, the product was detected via high-performance liquid chromatography (HPLC). The characteristic absorption wavelength of the rutin standard for HSCCC detection and HPLC analysis at 257 nm was tested by ultraviolet scanning analysis. The effect of solvent systems and mobile phase flow rate on the separation efficiency were then researched. Finally, the solvent system of V(ethyl acetate):V(n-butanol):V(water) = 4:1:5 was selected as the operating system for HSCCC. This work theoretically analyzed the impact of the molecular structure and polarity of flavonoids on the choice of solvent systems. The results showed that the mobile phase flow rate had a great influence on the separation efficiency. Furthermore, the separation efficiency increased as the mobile phase flow rate decreased. When the mobile phase flow rate was 5 mL/min, the peak time for flavonoids was 140 min, the retention of the stationary phase was 56.4%, and the purity of the product reached 93.8%. The results of this study greatly improved the purity of flavonoids in mulberry leaf and provided a strong support for the separation and purification of mulberry leaf extract.


1979 ◽  
Vol 12 (5) ◽  
pp. 271-276 ◽  
Author(s):  
S. A. Volkov ◽  
Yu. A. Sultanovich ◽  
K. I. Sakodinskii

2017 ◽  
Vol 1 (2) ◽  
pp. 44-52
Author(s):  
Andrea E. Rech ◽  
Cristina P. Farina ◽  
Pamela C. Lukasewicz Ferreira ◽  
Diogo Miron

This paper describes a fast and direct method for quantification of arginine and ascorbic acid (vitamin C) in effervescent tablets. HPLC-UV multidimensional chromatography (RP18 and cyanopropyl columns) was developed and validated. Phosphate buffer 10 mMpH 3.4 was used as mobile phase. Satisfactory resolution between the drugs was obtained with analysis time less than 8.0 min. Method was linear in the ranges of 140-320 mg.mL-1 and 240-560 mg.mL-1 for arginine and ascorbic acid, respectively. Precision showed RSD <2.0%. Recovery was 99.5% and 100.0% for arginine and ascorbic acid, respectively. Robustness was confirmed through factorial analysis 22 (pH and mobile phase flow rate as factors).


The Analyst ◽  
2017 ◽  
Vol 142 (3) ◽  
pp. 517-524 ◽  
Author(s):  
R. D. Arrua ◽  
A. Peristyy ◽  
P. N. Nesterenko ◽  
A. Das ◽  
D. M. D'Alessandro ◽  
...  

Microparticles decorated with metal–organic frameworks exhibited a unique flow-dependent separation selectivity (FDSS) effect for the isocratic separation of small molecules.


Crystals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 69 ◽  
Author(s):  
Paloma Martinez-Martin ◽  
Josefina Perles ◽  
Juan Carlos Rodriguez-Ubis

Luminescent mixed lanthanide metal−organic framwork (MOF) materials have been prepared from two polyheterocyclic diacid ligands, 2,6-bis(3-carboxy-1-pyrazolyl)pyridine and 2,6-bis(4-carboxy-1-pyrazolyl)pyridine. The crystal structures of the two organic molecules are presented together with the structures for the MOFs obtained by hydrothermal synthesis either with Yb(III) or mixed Tb(III)/Yb(III) ions. Different coordination architectures result from each ligand, revealing also important differences between the lanthanides. The mixed lanthanide metal−organic frameworks also present diverse luminescent behavior; in the case of 2,6-bis(4-carboxy-1-pyrazolyl)pyridine, where no coordinated water is present in the metal environment, Tb(III) and Yb(III) characteristic emission is observed by excitation of the bispyrazolylpyridine chromophore.


2020 ◽  
Vol 2 (12) ◽  
pp. 5682-5687
Author(s):  
Jun Zhao ◽  
Bo Jin ◽  
Rufang Peng

As an alternative approach for conventional mechanochemical synthesis, a novel gas–solid two-phase flow (GSF) synthetic technique for the mechanochemical synthesis of dual metal–organic frameworks (DMOFs) was reported for the first time.


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