Application polyamide resin adsorption mechanism analysis

Application polyamide resin adsorption mechanism analysis:

A polyamide is a polymer containing repeating units of class structure amide bond (ª² CONH ª²) , the structure of the general formula [NHRNHCOR2CO] n, O groups on the amide , N atom bonded protons in an acid medium and with positive charge , electrostatic forces are formed in the anion adsorption solution , the phenolic hydroxyl group with a compound rich phenols, acids , quinones , flavonoids and the like and hydrogen adsorption , adsorption depends mainly on the strength of these two compounds the number and location of the hydroxyl group to form a hydrogen bond association between the size of the capacity of the compound and a solvent or solvent and polyamide. Polyamide or solvent molecules with the ability of flavonoids to form hydrogen bond is stronger, the polyamide adsorption of these two compounds will be weaker . Column chromatography using a polyamide that is the nature of the various plants flavonoids , polyphenols and other adsorption , elution and separation , the so-called " hydrogen absorption " theory .

Polyamide chromatography separation mechanism , in addition to " hydrogen adsorption " doctrine but also have a "double chromatography " theory. The former can not explain when using chloroform : methanol eluent when , why aglucones than glycosides eluted first . The latter is considered that when a polar mobile phase ( aqueous solvent system ) eluting with a non- polar stationary phase a polyamide , which acts like a reversed-phase partition chromatography, chromatography, eluting with an organic solvent when the polyamide as a very stationary phase , which behaves like normal phase chromatography, partition chromatography . But the stationary phase ( adsorbent ) polarity is determined by its structure and nature of the decision itself , should not change with the change eluent Moreover, adsorption chromatography polyamide chromatography are not partition chromatography . Thus, " double chromatography theory " not reveal these two opposite phenomena generating the root cause .