Product characteristics
Polyamide is especially suitable for the separation of polyphenols, such as flavonoids, quinones, phenolic acids, carbonyl compounds, carboxyl compounds, etc. Because of its strong adsorption of tannin, it can also be used to remove tannin from crude extracts of plants.
Technical indicators:
Molecular weight: 14000 ~ 17000
Specific surface area: 5-10m2 / g
PH value: 6-7
Solubility: soluble in concentrated hydrochloric acid, formic acid, slightly soluble in acetic acid, phenol and other solvents, insoluble in water, methanol, ethanol, acetone, ether, chloroform and benzene and other commonly used organic solvents, which are more stable to alkali and less stable to acid, especially inorganic acid, and more sensitive at high temperature.
Product characteristics
Polyamide is especially suitable for the separation of polyphenols, such as flavonoids, quinones, phenolic acids, carbonyl compounds, carboxyl compounds, etc. Because of its strong adsorption of tannin, it can also be used to remove tannin from crude extracts of plants.
Technical indicators:
Molecular weight: 14000 ~ 17000
Specific surface area: 5-10m2 / g
PH value: 6-7
Solubility: soluble in concentrated hydrochloric acid, formic acid, slightly soluble in acetic acid, phenol and other solvents, insoluble in water, methanol, ethanol, acetone, ether, chloroform and benzene and other commonly used organic solvents, which are more stable to alkali and less stable to acid, especially inorganic acid, and more sensitive at high temperature. 1. Separation of flavonoids:
Since flavonoids have more than two aromatic nuclei and most of them have free phenolic hydrocarbon groups, they can be adsorbed on polyamide columns. Because aglycones have stronger adsorption capacity than glycosides, they can be washed down when they are eluted by water or dilute alcohol solution, while aglycones can only be washed down when they are eluted by concentrated alcohol solution.
2. Separation of acids and phenols:
The adsorption capacity of polyamide to aliphatic monoacids is small, but to aromatic acids and aliphatic polyacids is large, and the separation effect is good. The separation of phenols by polyamide chromatography is better.
3. Separation and removal of tannin
Tannin is a kind of polyphenolic substance, which can be easily adsorbed on polyamide resin column. The adsorption of low molecular tannin is reversible, and it can be separated by appropriate solvent elution. The adsorption of polymer tannin is irreversible and difficult to elute. No matter low molecular or high molecular tannins, their adsorption with polyamide is stronger than other compounds, so polyamide can be used to remove tannins.
Polyamide column chromatography plays an important role in the extraction and separation of natural products. However, in practical applications, there are often problems such as slow flow rate and low molecular impurities (oligomers of amides, etc.). In general, the problem of flow rate can be overcome by removing fine powder through pre screening or mixing with diatomite for granulation, while the interference of low molecular substances can be removed by pre washing with 5% methanol or 10% hydrochloric acid during column loading.
