Bio-Rad Bio-Rex® 5 Anion Exchange Resins User Manual
Page 3
groups will be in the hydroxide form, while the tertiary
amine groups will be in the free base form.
The physical properties of the resins are listed in
Table 1. These resins are thermally stable and resistant to
solvents (alcohols, hydrocarbons, etc).
Table 1. Summary of Properties
Order of
Thermal
Solvent
Resin Type
Active Group
Selectivity
Stability
Stability
Bio-Rex 5
R-N(CH
3
)
2
I>phenolate>
Good to
Good
intermediate
HSO
4
>CIO
3
>
60 °C
base
NO
3
>Br>CN>
anion HSO
3
>NO
2
>CI
exchanger
>HCO
3
>IO
3
>
H
2
COO>HC>
OH>F
AG 4-X4
R-CH
2
N+(CH
3
)
2
HSO
3
>HCit>
Good to
Good
AG 3-X4
CrO
3
>H
2
SO
4
>
60 °C
weakly basic
tartaric>oxalic
anion >H
3
PO
4
>
exchangers
H
4
AsO
4
>HNO
3
>HI>HBr>HCl
>HF>HCOO>
HAc>H
2
CO
3
Mechanism
Both AG 3-X4 and AG 4-X4 resin are available in
the free base form. Here the functional group is neutral,
and is not charged. When a mineral acid is passed over
3
and is certified to contain less than 100 microorganisms
per gram of resin.
AG 3-X4 resin and AG 4-X4 resin are both 4%
crosslinked and have a tertiary amino functional group.
The resins differ in their backbone resin matrix material.
AG 3-X4 resin has a styrene-divinylbenzene copolymer
lattice matrix, and AG 4-X4 resin has an acrylic matrix.
These two matrices differ in their physical and
mechanical strength, and in their inherent hydrophilic
nature. The styrene-divinylbenzene matrix (AG 3-X4
resin) is very strong mechanically, but is hydrophobic,
which can cause adsorption of large organic molecules or
proteins. The acrylic matrix (AG 4-X4 resin) is softer,
and therefore sensitive to crushing from excess flow rates
or very large column sizes. This material is hydrophilic
and is suitable for use with high molecular weight
organic compounds, proteins, and carbohydrates.
Bio-Rex 5 intermediate base resin contains primarily
tertiary, but also some quaternary, amines on a styrene-
divinylbenzene lattice. Bio-Rex 5 resin can be used to
separate organic acids from neutral sugars. When the
resin is regenerated with base, the quaternary ammonium
2
LIT207B 9/2/98 10:03 AM Page 2