Bio-Rad AG® MP-1M Anion Exchange Resins User Manual
Page 8
11
Section 4
Resin Conversion
Table 5 outlines common techniques for converting
ion exchange resins from one ionic form to another.
Resin conversion is most efficiently carried out in the
column mode. However, when choosing a column,
remember that the resin may shrink, or it may swell as
much as 100%, depending on the conversion.
10
Table 5. Techniques for Resin Conversion
Volumes of
Linear
Test for
Rinse:Vol.
Test for
Conversion
Sol’n/Vol.
Flow Rate
(4)
Type of
Completeness
Dl Water/
Completion
Resin
From
→
To
(1)
Reagent Used
of Resin
cm/min of Bed
Exchange
(3)
of Conversion
Vol. Resin
of Rinsing
AG 1 and
Cl
–
→
OH
–
1 N NaOH
(2)
20
IX
Cl
–(5)
4
pH<9
AG MP-1
OH
–
→
formate
1 N formic acid
2
2
N
pH<2
4
pH>4.8
Resins
Cl
–
→
formate
Use Cl
–
→
OH
–
and
20
IX-N
pH>4.8
then OH
–
→
formate
2
pH>4.8
Cl
–
→
acetate
same as formate except
IX-N
pH<2
4
pH>4.8
use 1 N HAc
AG 2 Resin
Cl
–
→
OH
–
1 N NaOH
(2)
2
2
IX
Cl
–(5)
4
pH>9
Cl
–
→
NO
3
–
0.5 N NaNO
3
5
IX
Cl
–
(
5)
4
1. Typical conversions are listed. The same reagents can be used to con-
vert from other ionic forms. Two steps regeneration, ion exchange fol-
lowed by neutralization, is included because of ease of conversion and
saving on expensive reagents.
2. Use U.S.P. or C.P. grade (low chloride).
3. N = Neutralization; IX = Ion exchange; IXN = two step process: Ion
exchange to acid or base form followed by neutralization with appro-
priate base or acid of salt, example (Step 1) Resin-Cl
–
+ NaOH
→
Resin-OH (IX); (Step 2) Resin-OH + H-formate
→
resin-formate +
H
2
O (neutralization).
4. For 50-100 or finer mesh resin. For 20-50 mesh about
1
⁄
5
the flow rate
is recommended
5. Test for Cl
–
in effluent: Acidify sample with a few drops of conc.
HNO
3
. Add 1% Ag NO
3
solution. White ppt indicates Cl
–
, yellow Br
–
or too basic.
LIT212C 6/17/98 12:25 PM Page 10