My GC capillary column was not sealed when I received it!

Traditionally, GC capillary column manufacturers have used several different methods to seal their products while in transit and storage. These sealing options include septa, silicone plugs, flame sealing, and press-fit caps.


I’m not going to discuss the advantages and disadvantages of these various approaches in this post. However, what I would like to address is a question that comes up periodically here in our technical service group:

What happens if you receive a brand new GC capillary column and one (or both) of the seals are no longer in place?

Is the column compromised? Will it still work? These are good questions to ask and consider.

Most of us have been told that exposing a capillary column to air (oxygen) can damage the phase. We are also aware that moisture or particles might enter an uncapped or unsealed column. What should you do if your column arrives without a proper seal?

Keep in mind that sealing a column is only intended to help protect column ends from damage and to keep particles from physically entering the column. These sealing mechanisms will not keep light or diffusive gases (such as hydrogen or helium) inside the column for very long.

Don’t panic. Although sealing the ends of columns is considered to be a good industry practice, occasionally, septa or silicone plugs will come loose, flame seals will break off, and column caps will disconnect. Yes, the column is now “exposed” and there is the possibility of “stuff” entering the column. However, the column is usually at relatively low (ambient) temperatures when this occurs, so the phase should be fine and it’s highly unlikely that the column has suffered any damage.

So, what should you do?

Install the column, leak-check the installation, and completely purge the column for a minimum of 20 minutes with clean, high quality carrier gas to help remove residual oxygen and moisture that may have entered the column during storage and transport.

This is a critical step. GC capillary columns MUST be thoroughly purged before being heated in the GC oven! Otherwise, stationary phase damage will occur.

Condition the column per the manufacturer’s recommendations. This will stabilize the baseline and minimize bleed. The following links provide detailed information on how to condition your columns:

How to Condition a New Capillary GC Column

PLOT column instruction sheet

Micropacked (0.53mmID) column instruction sheet

How do I condition a new packed or micropacked column?

In summary, it’s very unlikely that a missing end seal (or two) will result in damage to your column.

Thank you for reading!

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