2000 MS Hardware Maintenance
124
GC Maintenance
NOTE: Rinsing the glass inserts with strong acids or bases or heating to a high
temperature will remove the deactivation coating on the glass inserts. Rinsing the
glass inserts with solvents or mixed solvents will not remove the deactivation
coating.
Deactivate the Glass Insert
Follow these steps to deactivate the glass insert in the 1079 Injector.
NOTE: This procedure can be used on all glass inserts except inserts packed
with 10% OV-101 on Chromosorb W-HP (03-918956-00). Up to three inserts can
be deactivated at a time using this procedure.
1. In a 10 mL glass graduated cylinder, add 0.5-1 mL of dimethyldichlorosilane.
Fill to 10 mL with isooctane, hexane or toluene.
2. Cover the top of the graduated cylinder with aluminum foil and place the
cylinder in an ultrasonic bath. Sonicate for 30 sec to mix the solution.
3. Add up to 3 inserts to the solution.
NOTE: Deactivate glass inserts only after they have been thoroughly cleaned
using the above procedure.
4. Sonicate the inserts in the cylinder for 10 min. Rinse the inserts 3 times with
10 mL isooctane, hexane or toluene. Each rinse should include 2-3 min of
sonication.
5. Add 10 mL of methanol and sonicate for 2-3 min. Decant the methanol and
repeat the methanol rinse step.
6. Decant the methanol. Transfer the deactivated inserts to a small clean glass
beaker. Cover the beaker with aluminum foil and bake at 200 °C for 1 hour.
7. After the inserts cool to room temperature, store them in a clean screw cap
glass vial or the original packaging.
To clean the injector body, proceed as follows:
1. Set the column oven temperature to 45
°
C and the 1079 injector temperature
to 50
°
C. Wait for the zones to reach their set temperatures and then turn
the column oven off by pressing the “TURN OVEN OFF” softkey located in
the Column Oven section of the method.
2. Use the 5/16" open-end wrench to loosen the capillary column nut.
3. By hand, carefully withdraw the fused silica column and nut from the injector
assembly. Set the column nut and column end on the floor of the GC oven.
