Cross-linked polyvinylpyrrolidone also called crospovidone or popcorn polymer is a common pharmaceutical excipient used as a disintegrant in pharmaceutical tablets after they are ingested and come into contact with water. Consequently it is a relatively cheap, pure, and inert material. Cross-linked polyvinylpyrrolidone is insoluble in all solvents. The metal complexing agent 8-quinolinol has a strong affinity for this polymeric material. Its association is by strong hydrogen bonding between the phenolic OH of the agent and the lactam oxygen of the polymer.
With 8-quinolinol bound to
the surface of crospovidone, metals are readily retained such as cadmium, zinc,
lead, copper, iron, manganese, nickel, cobalt and chromium salts. It would seem
that the metal is being complexed by the neutral form of 8-hydroxyquinolinol
since the hydrogen bond presumably must be preserved to bind with the polymer.
This crospovidone polymer by itself might be applicable for separating phenols and polyphenols because in my notes it is written: Phloroglucinol>resorcinol>phenol and pyrogallol>catechol>phenol. The more phenols in the molecule the stronger we can imagine the molecule might bind to the polymer.
This crospovidone polymer by itself might be applicable for separating phenols and polyphenols because in my notes it is written: Phloroglucinol>resorcinol>phenol and pyrogallol>catechol>phenol. The more phenols in the molecule the stronger we can imagine the molecule might bind to the polymer.
A lower than pharmaceutical
grade of crospovidone might be available inexpensively from a manufacturer of
this medicine excipient.
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