Submitted by anthias on
Connecting capillary columns together using the press-fit connector:
- Lower the carrier gas pressure through the column/connector to a minimum value that maintains a low flow through the column.
- Insert the trimmed end of each column firmly into the press-fit connector, wearing a latex glove will help get a good grip on the column so that you can push it in fully. You may be able to see a ring where the end of the column is sealing against the inside of the press-fit. If you remove it you should start with a new press-fit again, as the inside of the press-fit may have been scratched which would lead to a leak.
- Once both ends have been inserted, check each is leak-free.
- Gradually increase the GC oven temperature to approximately 200°C (check this is within the column limits). This will soften the polyimide coating at the column ends, causing the polyimide to flow and then bake to seal against the connector. If this step is done at a normal carrier gas pressure, sometimes the pressure combined with the softened polyimide pushes the column end from the connector causing a leak.
- Leave for approx 30 minutes; cool the oven and leak-check the connection again. If leak-free, restore full operating pressure to the column and use.
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