Page 173 - Applied Pharmacognosy

What is Inside the Column-The Stationary Phase

Ion Exchanger is another Possible Column Type

❑ Anion (NH4+) and cation (-COO-) exchangers are preferable

exchangers in HPLC. Electrostatic interaction

H (Coulomb force)

Anion exchange N+ H

Cation exchange H + + + + +
COO- + + + ++

Cation Exchanger Anion Exchanger

Strong -SO3- (SCX) -NR3+ (SAX)
Weak -COO- (WCX) -NHR2+ (WAX) 172