Thermo Scientific ISQ, User Manual

Page: 34 / 152

2
Changing the Column
Replacing the Factory Installed Column
12 ISQ User Guide Thermo Scientific
Expect a K-factor of approximately 0.7 – 0.9 for a 15 m, 0.25 mm i.d. column
(1.3 – 2.0 for a 30 m, 0.25 mm i.d. column). If the column does not report a
K-factor within this range or within 0.1 units of the previous stored value, check for a
leak or broken column using the leak detector. The K-factor is a measured resistance
for the column. A K-factor that is too low may indicate a leak in the system, while a
K-factor that is too high may indicate a blockage.
g. Fix any issues found and rerun column evaluation until an appropriate K-factor is
achieved.
17. Disconnect the column flowmeter:
a. Disconnect the column from the column flowmeter connector.
b. Remove the column flowmeter connector, including its fittings, from the oven and
set them aside.
c. Close the GC door.
18. Condition the column before inserting it into the ISQ system. Column conditioning
consists of passing a carrier gas through the column heated to a programmed temperature
as described in the column manufacturer’s instructions.
a. If there are no conditioning instructions, perform the column conditioning by setting
a final temperature 10 °C–20 °C below the column’s recommended maximum
temperature.
b. Run the slow temperature program that is recommended by the manufacturer. A
typical program would hold the column at 40 °C (104 °F) for 15 minutes, and then
ramp at 10 °C/min (50 °F/min) up to 10–20 °C below the maximum allowed
column temperature. Hold the column at this temperature for two hours.
CAUTION INSTRUMENT DAMAGE: The material released from the column
(column bleed) during conditioning may contaminate the ion source if the
column is inserted into the transfer line during the high-temperature stage of
conditioning.
WARNING FIRE HAZARD:
Do not use hydrogen as the carrier gas for
conditioning your column. It could vent into the oven and present an explosion
hazard.
CAUTION INSTRUMENT DAMAGE: Never exceed the column manufacturer’s
maximum operating temperature.