Restek GC Serie Guia De Instalacion página 2

2 GC Column Installation Instructions
The Restek Innovations and Technical Services specialists have
found this to be a reliable sequence for avoiding problems when
installing a capillary GC column.
Instrument Preparation & Column Installation
1. Cool all heated zones.
2. Visually inspect indicating oxygen and moisture traps. Replace
saturated traps.
3. Examine the inlet and the detector. Clean or replace all dirty or
corroded parts.
4. Replace the inlet liner, septum, and the injector seals (o-rings,
inlet seals, ferrules, etc.).
5. Mount the column in the oven with a support that protects it
from scratches. Center the column in the oven. This ensures
uniform heat exposure generating consistent retention times.
Note: 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. If you have the cage with high temperature string, do
not remove the string that holds the column in the cage!
6. Uncoil the ends to make sure the ends are long enough to reach
the injector and detector. Cut a few centimeters from each end
of the column.
Note: To cut a fused silica column, use the smooth edge of a ceramic
scoring wafer (cat.# 20116).
7. 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 any material scraped from the ferrule onto the edge of
the column.
8. Install the column the appropriate distance in the injector, as
indicated in your instrument manual.
9. Set the carrier gas to the flow rate or inlet pressure recommend-
ed for the column or to your method flow rate/pressure. Confirm
presence of column flow by immersing the column outlet in a
vial of solvent and looking for bubbles.
Warning: If you are using hydrogen as your carrier gas, you must safely vent
the open end of your column out of the oven to prevent hydrogen buildup
and minimize the potential for explosion.
10. Flush the column at ambient temperature with carrier gas: at
least 5 minutes for a 25-30 m column and 10 minutes for a
50-60 m column.
11. Set the injector temperatures. Do not exceed the column's maxi-
mum operating temperature (listed on the column box). Check
inlet for leaks using a Restek® Electronic Leak Detector (cat.# 22839).
12. Install the column into the detector as described in Steps 7–8. Set
the detector gases and temperatures to proper settings.
13. Check the detector connections for leaks, using a Restek®
Electronic Leak Detector (cat.# 22839).
14. Verify the carrier gas flow is at the rate you intend to use for
your analysis. 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 time. A symmetric peak
indicates the column is installed correctly. Adjust the carrier gas
flow as necessary to obtain proper dead time.
16. Condition the column 20 °C above the final analysis temperature
of your method. Do not exceed the column's maximum operat-
ing temperature. For most applications, 1 hour of conditioning
is sufficient. For sensitive detectors or low level analysis, longer
conditioning times or conditioning the column at the maximum
temperature may be beneficial. Extended time at high tempera-
tures will not adversely affect column performance as long as
precautions are taken to make sure the carrier gas is clean and is
filtered for oxygen and water.
17. To confirm proper column and system performance, analyze a
column test mix for a new method or a known standard.
18. Your GC system is now ready to be calibrated and acquire data.
Note: For some types of sensitive detection systems, like MS, PID, and
PDD, it is recommended to condition the column as listed in Step 16
without making the connection to the detector. In this case, plug off the
detector during conditioning. After conditioning, continue with Step 12.
Note: When you intend to condition thick-film coated columns (film thick-
ness > 1 µm) at temperatures near the maximum operation temperature, it
is recommended to do the initial 1-2 hours conditioning without a connec-
tion to the detector and repeat procedure above, starting at Step 12.
Standby Conditions
Short-Term: Leave the column in the GC with the carrier gas flow
on at an oven temperature of 100-150 °C.
Long-Term: Remove the column from the GC 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 www.restek.com/gcinstall or contact your
Restek representative.
www.restek.com/gcinstall