Replacement of Septum
Preparation¶
First, set the instrument to a state in which it can be serviced (Maintenance Mode).
- Enter maintenance mode using the workstation.
- Enter maintenance mode using the the instrument monitor. (When the GC main unit is GC-2030)
- Enter maintenance mode using the maintenance button on the instrument. (When the GC main unit is GC-2050)
Required devices¶
No. |
Parts name |
Category |
Required number |
Note |
|---|---|---|---|---|
① |
Tweezers |
1 |
||
② |
Septum |
1 |
Various optional parts are available. |
|
③ |
Spacer |
1 |
Parts for SINJ. |
Procedures¶
Step 1¶
GC-2030¶
Open INJ/DET cover (★1).
GC-2050¶
For GC-2050, do maintenance work without opening the INJ/DET cover. Turn off the power before opening the INJ/DET cover.
Step 2¶
Turn the septum nut (★2) counterclockwise to remove it.
The appearance depends on the injection port. For SINJ, it is as follows.
Step 3¶
Remove old septum (★3) with tweezers (①).
For a SINJ, there is a spacer (③) under the septum. When replacing it, make sure that the surface with the slit faces downward.
Step 4¶
Install a new septum (②).
Hold down the septum with flat surface of tweezers for easier installation.
Step 5¶
Turn the septum nut (★2) clockwise, fully tighten it, and return it halfway.
-
If it is not returned halfway, the septum may become hard and the needle of the syringe may bend when the syringe is inserted.
-
Returning halfway after fixing prevents the septum from excessive compression, which makes it difficult to insert the syringe.
Step 6¶
Close INJ/DET cover.
Step 7¶
Exit maintenance mode using the following procedure according to the relevant instrument, and reset the consumable usage counter.
- Exit maintenance mode using the workstation.
- Exit maintenance mode using the the instrument monitor. (When the GC main unit is GC-2030)
- Exit maintenance mode using the maintenance button on the instrument. (When the GC main unit is GC-2050)
Type of bleeding depends on the septum, and they appear on chromatogram as different patterns. For high-sensitivity analysis, use a septum of which bleeding does not appear in positions that interfere with the peaks of the target compounds. After extraction with hexane, etc. for a few hours, conditioning for a few hours at about 120 °C to 150 °C (less than about 200 °C for LL/HT septum) may be effective to decrease bleeding.
However, extraction with organic solvent is not required when using a CRS septum (AG3) because it is a low-bleed septum.