Waters IC-Pak Column and Guard - Manual (Page 9)

[ Care and Use ManUal ]
IC-Pak Column and Guard Column 9
V. Care and maIntenanCe
a. Troubleshooting
Table 11: Column Problems and Solutions
b. Column Storage
Remove columns not in use for over 72 hours and store:
•
Anion columns in Borate Gluconate Eluent
• Cation columns in the eluent used for analysis (either EDTA/HNO
3
or
EDA/HNO
3
)
Eluent may be left in the columns with the columns connected to the
system for short-term storage.
When storing columns:
• DO NOT store columns in water. To prevent growth of bacteria store the
columns in the eluent being used. Fill the column with eluent, replace
the end plugs, and return the column to its box.
• DO NOT allow the column to dry out. Allowing the column packing to
dry out can result in poor chromatographic performance. Eluent may
be left in the columns with the columns connected to the system for
short-term storage.
• Store at 15 °C to 35 °C. Freezing during storage will cause perfor-
mance degradation.
c. Cation Guard Column Preparation and Regeneration
Monovalent cation analysis may require frequent changing
or regeneration of the guard column due to interference from
polyvalent cations. Change or regenerate the column when:
• k’ changes or there is a noticeable decrease in retention time
(greater than 15%)
• Fused peaks are seen
• Resolution is abnormal
Changing or regeneration of the guard column may be frequent,
depending on the particular analysis. Monovalent detection using a
sample matrix containing heavy metals may load the column easily.
To regenerate the column, flush the column with 200 mL 0.1 M HNO
3
at a flow rate of 1.2 mL/min.
Symptom Conditions Corrective Action
Excess pressure buildup Filters plugged with
particulates. Check for
injector and pump seal
shedding
Back flush column at
0.1 mL/min with eluent.
Always filter eluents
and samples. Use an
in-line precolumn filter
between the pump and
injector.
Sample precipitates
on column (sample no
soluble in eluent)
Black flush column at
0.1 mL/min with elu-
ent. Use a solvent that
is compatible with the
sample.
Clogged tubing Unclog or replace tub-
ing.
Loss of resolution,
broad peaks, low plate
counts
Polyvalent electrolyte
accumulation
IC-Pak A – Slowly
purge (below 1 mL/min)
with 100 mL of the
following solution:
In a 1 liter volumetric
flask combine 50 mL
eluent concentrate,
120 mL Acetonitrile,
and 20 mL Butanol.
Fill to the mark with
18 megohm water and
filter.
IC-Pak C – Slowly purge
(below 1 mL/min) with
50 mL of 100 mM
HNO
3
-
Failing injector Repair injector.
Contaminated column Slowly purge with
strong solvent.
Insufficient equilibration Continue equilibration.
Incorrect 0.040-inch
stainless steel tubing
Install correct
0.009-inch stainless
steel tubing.