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CH3041
ON-LINE LECTURE 22
ION CHROMATOGRAPHY
• Ionic compounds cannot be separated by
GC or HPLC. The technique used is Ion
Chromatography (IC) which is the analytical
variant of ion-exchange chromatography.
GC or HPLC. The technique used is Ion
Chromatography (IC) which is the analytical
variant of ion-exchange chromatography.
• Ion-exchange chromatography uses an ion
exchange resin as the SP. A resin is a porous, amorphous, organic material; cross linked styrene-divinylbenzene copolymer is a common SP.
exchange resin as the SP. A resin is a porous, amorphous, organic material; cross linked styrene-divinylbenzene copolymer is a common SP.
The styrene substituents are
-SO3- (sulphonate) for cation exchange or
-NR3+ (ammonium) for anion exchange.
-SO3- (sulphonate) for cation exchange or
-NR3+ (ammonium) for anion exchange.
• The degree of cross linking defines the
pore sizes. (eg. Dowex X2 low; X12 high)
2% (large) 12% (small)
pore sizes. (eg. Dowex X2 low; X12 high)
2% (large) 12% (small)
