Bio-Rad Bio-Rex® Reactor Grade Resins User Manual
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6.
Slowly pour the solution to be deionized into the
reservoir above the column, then elute slowly through
the column taking care not to disturb the resin bed.
Discard the first 1-2 bed volumes of the solution.
7.
The quality of the deionized solution may be verified
by measuring its conductivity against the conductivi-
ty of the starting solution.
Table 2. Guidelines for Column Deionization
Approximate Volume
Column Size
Weight of
of Deionized Water*
(diameter x length)
Resin (g)
(liters)
0.5 x 20
2.6
1.5
1.0 x 50
27.0
6.7
1.5 x 100
118.0
29.0
2.5 x 100
325.0
80.0
5.0 x 100
1,300.0
325.0
15.0 x 120
13.6
3,500.0
* Based on using 100 ppm NaCl. This volume will vary depending on ini-
tial water quality.
The dye (D) form of resin may be used to deionize
solutions until the dye begins to fade from blue to gold,
indicating capacity is exhausted. In a large column, the
dye will change color starting at the top of the column,
and deionization will continue until the color change
Column Method
Use mixed bed resin in a column to deionize larger
volumes (liter volumes) of mobile phase such as water.
The following procedure gives guidelines for column
deionization for a range of volumes; use Table 2 to select
the column size and quantity of resin.
1.
Select a column with a length to diameter ratio of at
least 5 to 1. Refer to Table 2.
2.
Weigh out approximately 0.6 grams of resin for every
1 ml of column volume.
3.
Using the resin as it comes from the bottle, pour a
small portion of resin into the column. Pour the col-
umn in sections, a scoop at a time, to prevent separa-
tion of the anion and cation resins. Add water,
keeping about 1/4 inch of water above the resin.
4. Repeat step 3, alternating resin and water, until the
total amount of resin is added. The resin will have a
tiger's tail appearance; more bands will mean a higher
efficiency. Remove any trapped air bubbles by tap-
ping the column during packing.
5.
When the column is packed, wash the resin with 3
bed volumes of deionized water. Discard wash.
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