Prefilled Poly-Prep
Columns for
Ion Exchange
Chromatography
Instruction Manual
®
Table of Contents
Section 1 Introduction ............................1
Section 2 Column Description................2
Section 3 Instructions For Use...............2
Section 4 Ion Exchange Capacity ..........3
Section 5 Flow Rate Characteristics......4
Section 6 Chemical Compatibility.........5
Section 7 Temperature Limits ...............6
Section 8 Troubleshooting......................6
Section 9 Ordering Information ............8
Section 1
Introduction
Prefilled Poly-Prep columns are small
polypropylene columns containing ion
exchange resins. These columns combine the
analytical quality and wide selection of
Bio-Rad’s ion exchange resins with the convenience of small, disposable columns. Poly-Prep
columns are especially useful in sample preparation for HPLC, GC, IC, and AA analysis.
Multi-purpose cap
Volume markings
10 ml reservoir
2 ml bed
(fully visible)
Fig. 1. Poly-Prep column.
1
Built-in bed support
Luer tip fitting
Snap-off seal
Poly-Prep columns are ideal for routine
applications in which a small amount of chromatographic medium is used and then discarded, or for multiple sample clean-up applications. They are a time-saving and versatile
replacement for Pasteur pipets and other
improvised columns.
Section 2
Column Description
The graduate 0.8 x 4 cm columns, constructed of high density polypropylene, hold a
standard bed volume of 2 ml of chromatographic media, and include an integral 10 ml
reservoir. A Kynar
umn acts as a bed support for the resin packing. At the bottom of the column is a snap-off
seal, which leaves a male Luer tip fitting when
it is removed.
Prefilled Poly-Prep columns are shipped
sealed, to prevent the resin packing from drying. Columns are packed in deionized water.
During transport, the resin may move to the
top of the column. This is corrected by shaking
the column and allowing the resin to settle
before use. The columns should be stored
upright, in a dark, cool location.
®
20 µm frit inside the col-
Section 3
Instructions for Use
1. Shake the column and allow all the resin to
settle to the bottom.
2
2. Remove the column cap to allow the eluant
to flow freely.
3. Snap off the seal at the bottom of the
column.
4. Monitor the level of liquid in the reservoir,
and do not allow the resin to become dry.
5. Rinse the resin with several bed volumes
(at least 2 ml) of the sample solvent.
Discard rinse.
6. Add sample.
7. Collect effluent.
8. To reduce the flow rate or stop the flow,
use a Luer 3-way stopcock or the yellow
end-cap.
Section 4
Ion Exchange Capacity
The resin packing determines the ion
exchange capacity of each prefilled Poly-Prep
column. Table 1 lists the ion exchange capacity
of the resin in each prefilled Poly-Prep column.
Table 1. Ion Exchange Capacity of
Prefilled Poly-Prep Columns
Resin (nominal meq/2 ml of rein)
®
1-X8 resin 2.4
AG
AG 2-X8 resin 2.4
AG 50W-X4 resin 2.2
AG 50W-X8 resin 3.4
®
Chelex
100 resin 0.8
Bio-Rex®70 resin 4.8
Ion Exchange Capacity
3
The ion exchange capacity, usually
expressed as meq/ml of resin, is equivalent to
the number of ion exchange sites per unit volume of resin. The following examples shows
the calculated volume of 1 N sodium hydroxide that would be required to convert the 2 ml
of resin in a prefilled AG 50W-X8 (H+) PolyPrep column from the hydrogen form to the
sodium form. In general, it is recommended to
use only 70-80% of the theoretical capacity of
an ion exchange resin.
1 N = 1 equivalent/liter = 1 milliequivalent/milliliter (1 meq/ml)
AG 50W-X8 ion exchange capacity = 1.7 meq
1.7 meq/X ml = 1 N
1.7 meq/1 N = X ml
X = 1.7 ml
Therefore, 1.7 mls of 1 N NaOH required
to convert the AG 50W-X8 resin to the sodium
form.
Section 5
Flow Rate Characteristics
The flow rate of an ion exchange resin is
primarily determined by the particle size of the
resin. Using gravity flow, the expected flow
rate for 100-200 mesh resin in prefilled PolyPrep columns is approximately 4-6 ml/minute.
The flow rate for 200-400 mesh resin is
approximately 1.5 ml/minute.
Bio-Rex 70 resin has slower flow rate than
AG or Chelex resins. Bio-Rex 70 100-200 mesh
resin flows at approximately 1.0 ml/minute.
4
Section 6
Chemical Compatibility
Table 2 gives the chemical compatibility
of prefilled Poly-Prep columns. While the column is often very resistant, the compatibility of
the resin must be considered.
Table 2. Chemical Compatibility of
Column
Chemical Compatibility*
Acetic acid, 50% S
Acetone S
Acetonitrile S
Ammonium hydroxide S
Chloracetic acid S
Chromic acid, 50% U
Diethyl ether L
Dimethyl formamide S
Dimethylsulfoxide S
Ethyl alcohol S
Ethylene glycol S
Formamide S
Glacial acetic acid S
Glycerine S
Hydrochloric acid, 35% S
Isobutyl alcohol S
Isopropyl alcohol S
Methanol S
Perchloric acid U
Phosphoric acid S
Propylene glycol S
Sodium hydroxide, 50% to Sat. L (U for anions)
Sulfuric acid, 60% S (U for anions)
Sulfuric acid, 98% U
Urea, 8 M S
* S = Satisfactory U = Unsatisfactory L = Low
5
Section 7
Temperature Limits
Increases in temperature tend to decrease
resin selectivity, and can be used to decrease
elution times. Increased temperature also
increases exchange kinetics, resulting in
sharper resolution. However, some temperature
limits must be observed with ion exchange
resins. Table 3 gives the maximum temperature for each resin packing.
Table 3. Temperature Limits
Resin Packing Temperature (°C)
AG 50 resin 150
AG 1 resin 150 (50 °C if converted
AG 2 resin 150° (30 °C if converted
Chelex 100 resin 75
Bio-Rex 70 resin 100
Maximum
–
to OH
form)
–
to OH
form)
Section 8
Troubleshooting
1. Variation in color (lot-to-lot): Sometimes
the color of the resin may vary from lot to
lot. This will not affect the ion exchange
capacity of the resin.
2. Unusual odor: Amines will sometimes
cleave from anion exchange resin after prolonged storage. This is not unusual. They
6
can be removed easily by rinsing with 2-3
bed volumes of mobile phase.
3. Effluent is red: After prolonged storage,
sulfonic acid will sometimes leach from
AG 50 strong cation exchange resin, yielding a red effluent. Wash the resin with
mobile phase or water until the color is no
longer visible.
4. Cloudy effluent: The initial rinse may con-
tain a small quantity of resin. Discard the
wash and continue as normal.
5. Flow rate too fast: Use a stopcock to adjust
the flow rate.
6. Column runs dry: If the resin is allowed to
become dry, air bubbles can form in the
column bed. This will affect the flow and
the separation efficiency. To correct this,
add extra mobile phase, stop-up both ends
of the column, shake the column, and
allow the resin to settle. Proceed as normal.
If you have any questions about using prefilled Poly-Prep columns, call our toll-free
technical services number, 1-800-424-6723 (in
the U.S.), or contact your local Bio-Rad representative.
7
Section 9
Ordering Information
Catalog Ionic Mesh
Number Column Packing Form Size
731-6211 AG 1-X8 Resin, 50 Cl
731-6212 AG 1-X8 Resin, 50 Cl
731-6221 AG 1-X8 Resin, 50 HCOO
731-6247 AG 2-X8 Resin, 50 Cl
731-6225 AG 50W-X4 Resin, 50 H
731-6213 AG 50W-X8 Resin, 50 H
731-6214 AG 50W-X8 Resin, 50 H
731-6217 Chelex 100 Resin, 50 Na
731-6232 Chelex 100 Resin, 50 Na
731-6228 Bio-Rex 70 Resin, 50 Na+100-200
Note: Special order prefilled Poly-Prep
columns are available with the chromatographic material of your choice. A minimum
order of 1,000 columns is required for special
order. Prices quoted on requested.
Accessories
Catalog
Number Product Description
731-7005 Poly-Prep Column Rack
731-1550 Poly-Prep Columns, empty, 50
Luer-Lock Stopcocks
732-8102 Luer-Lock 2-Way Stopcock
732-8103 Luer-Lock 3-Way Stopcock
732-8107 Solvent Resistant 3-Way Stopcock
–
100-200
–
200-400
–
200-400
–
100-200
+
200-400
+
100-200
+
200-400
+
100-200
+
200-400
Kynar is a registered trademark of E.I. DuPont de
Nemours and Co.
8
Bio-Rad Laboratories, 2000 Alfred Nobel Dr., Hercules, CA 94547
LIT84 Rev B
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