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GCCOLUMNS |
CAPILLARYCOLUMNS
Column Installation
The Restek Innovations and Technical Services specialists have found this to be a
reliable sequence for avoidingproblemswhen installing a capillaryGC column.
InstrumentPreparation&Column Installation
1. Cool all heated zones.
2. Visually inspect indicating oxygen andmoisture traps. Replace saturated traps.
3. Examine the inlet and the detector. Clean or replace all dirty or corroded parts.
4. Replace the inlet liner and septum, and the injector seals (O-rings, inlet seals, ferrules, etc.).
5. Mount the column in the ovenwith a support that protects it from scratches. Center the column in the oven.
This ensures uniform heat exposure generating consistent retention times.
•Restek has two types of cages for fused silica columns, an 11-pin cage and the original cage that uses
high temperature string to hold the column in place.
Ifyouhave thecagewithhigh temperature
string,donot remove thestring thatholds thecolumn in thecage!
6. Uncoil the ends tomake sure the ends are long enough to reach the injector and detector. Cut a few
centimeters from each end of the column.
•To cut a fused silica column, use the smooth edge of a ceramic scoringwafer (cat.# 20116).
7. While pointing the inlet end of the column downward (to prevent shards from falling into the column), slide
the nut and appropriate size ferrule onto the inlet end of the column. Cut an additional 2 cm from the end
of the column to remove anymaterial scraped from the ferrule onto the edge of the column.
8. Install the column the appropriate distance in the injector, as indicated in your instrumentmanual.
9. Set the carrier gas to the flow rate or inlet pressure recommended for the column or to yourmethod flow
rate/pressure. Confirm presence of column flow by immersing the column outlet in a vial of solvent.
10. Flush the column at ambient temperaturewith carrier gas: at least 5minutes for a 25-30m column and
10minutes for a 50-60m column.
11. Set the injector temperatures. Do not exceed the column’smaximum operating temperature (listed on the
column tag). Check inlet for leaks.
12. Install the column into the detector as described in the instrumentmanual. Set the detector gases and
temperatures to proper settings.
13. Check the detector connections for leaks, using aRestek Electronic LeakDetector (cat.# 22839).
14. Verify the carrier gas flow is at the rate you intend to use for your analysis. (Use theRestek ProFlow 6000
flowmeter, cat.# 22656, to ensure accurate flowmeasurement.) Set the split vent, septum purge, and any
other applicable gas rates as appropriate.
15. Inject an unretained compound, to verify the column is installed correctly and to determine the dead
volume time for checking column flow.The type of detector and column typewill determinewhich
compound to inject. A symmetric peak indicates the column is installed correctly. Adjust the carrier gas flow
as necessary.
16. Condition the column 20 °C above the final analysis temperature of yourmethod. Do not exceed the
column’smaximum operating temperature. Formost applications, 1 hour of conditioning is sufficient.
For sensitive detectors or low level analysis, longer conditioning times or conditioning the column at the
maximum temperaturemay be beneficial. Extended time at high temperatureswill not adversely affect
column performance as long as precautions are taken tomake sure the carrier gas is clean and is filtered
for oxygen andwater.
17. To check instrument performance, analyze a column testmix for a newmethod, or a known standard to
confirm proper column and system performance.
18. Your GC system is now ready to be calibrated and acquire samples.
Note1:
For some types of sensitive detection systems, likeMS, PID andPDD, it is recommended to condition
the column as listed in Step 16withoutmaking the connection to the detector. In this case, plug off the detector
during conditioning. After conditioning, continuewith Step 12.
Note2:
Also, when you intend to condition thick-film coated columns (film thickness>1µm) at temperatures
near themaximum operation temperature, it is recommended to do the initial 1-2 hrs conditioningwithout a
connection to the detector and repeat procedure above, starting at Step 12.
StandbyConditions
Short-Term:
leave the column in theGCwith carrier gas flowing at an oven temperature of 100-150°C.
Long-Term:
remove the column from theGC and seal the ends by gently and carefully pushing each end into
the curved edge of a septum. Store the column in the original box away from strong lighting.
If you have any questions or problems installing a Restek column, visit
or call
Technical Service at 800-356-1688 or 814-353-1300, ext. 4, or contact your Restek representative.
GCColumn InstallationChecklist
ScottGrossman, ApplicationsChemist
Checking for leaks, usinga thermal
conductivity leakdetector (step13).
Website :
E-mail :
TelNo : 03 9762 2034 . . . inAUSTRALIA
Mar 2011
