Waters Protein-Pak PW Ion-Exchange Column - Manual (Page 4)

[ Care and Use ManUal ]
Protein-Pak PW Ion-Exchange Columns 4
a. Column Efficency
Waters Corporation measures the efficiency of the Protein-Pak ion-
exchange columns using the 1/2 peak height method. Plate count, as an
expression of efficiency, is determined as shown in the following diagram .
v. TROUbleshOOTINg
Figure 2: Typical Column Problems and Solutions
Problem Cause Solution
Excess pressure
buildup
• Filters
plugged with
Particulates
• Sample precipi-
tates on column
(sample not
soluble in mobile
phase)
• Clean filters in an ultrasonic
bath or replace. Always filter
solvents and samples
• Slowly purge with a strong
eluent appropriate to dis-
solve the contaminate.
Loss of resolution,
broad peaks,
low plate counts • Contaminated
column,
insufficient
equilibration
• Filters partially
plugged
• Column collapse
and void formation
• To wash or regenerate
columns, 0.1-0.2 NaOH
solutions are very effective.
Usually columns can be
regenerated by making
several 1-2 mL injections of
0.1-0.2 N NaOH. If this does
not improve column perfor-
mance, wash column with
several 1-2 mL injections
of 20-40% acetic acid.
• Since this may occur during
the first two weeks of use,
Waters Corporation will
replace any column with
this defect.
• Replace or clean inlet and
outlet filters.
N= Column Efficiency (plates)
V
r
= Volume peak apex (μL)
W 1/2= Volume of peak at
1/2 peak height (μL)
Column Name Part Number Mobile
phase
Optimal
Flow
Rate
(mL/min)
Test
Sample
Peak
Protein-Pak DEAE
5PW 7.5 mm x
75 mm
WAT088044 HPLC
grade
water
1 2 μL
acetone
Protein-Pak
SP-5PW
7.5 mm x 75 mm
WAT088043 HPLC
grade
water
1 2 μL
acetone
Protein-Pak
SP-5PW
21.5 mm x
150 mm
WAT010640 HPLC
grade
water
5 10 μL
acetone
d. Storage Consideratons
Store columns in distilled water. If microbial contamination is a
concern, refrigerate at 4-6 °C. DO NOT FREEZE.
DO NOT allow buffers or other potentially harmful materials to
remain in the system overnight when not being used. Run buffers with
a slow flow rate (0.1 mL/min) overnight if necessary.
Return the column to its box with the end caps firmly in place for
storage. Allowing steel columns to dry out can result in poor chro-
matographic performance.
Iv. TesT CONDITIONs
Columns are thoroughly tested in adherence to our specifications. Since
slight variations in your results will occur depending on the equipment used,
test sample makeup, and equipment settings and condition, perform the test
sample run given here for your new column and record the results (retention
time and the settings used) before attempting the first analysis. Use these
results for comparison throughout the life of your column.
Detectors should be run at 254 nm or 280 nm (UV). Otherwise, use instru-
ment settings that produce an acceptable test peak (this may mean using a
lower sensitivity on the UV detectors than normally practiced for a specific
analysis).
Note: Be sure to record results and instrument setting (and configurations) to
allow exact reproduction and comparison in the future.