If you’ve ever needed to connect a guard column to an analytical column, or connect two columns together, or repair a broken column, you know how essential it is to have a clean, reliable connection.
In today’s Restek Tip, we’re going to show you how to use a Press-Tight connector. They come in a variety of types and have multiple uses, from connecting two columns together, to even repairing a broken column. Let’s connect some columns!
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If you’ve ever needed to connect a guard column to an analytical column, connect two columns together or even repair a broken column, you know how essential it is to have a clean, reliable connection. In today’s Restek Tip, we’re going to show you how to use a Press-Tight connector to make those connections.
We’ll start by cutting the ends off of our GC capillary columns to create nice, square edges. Once you have completed the cut, be sure to clean the end of the column using a lint-free wipe with a solvent like methanol or acetonitrile to remove any fragments. Now, while holding the Press-Tight connector in one hand, gently insert the column end into the connector until it is gripped firmly in the radial restriction. A continuous brown ring where the column end compresses inside the connector indicates a proper connection. Be careful not to press too hard as this could crush the end of the column. And now we simply repeat the process to insert the other column into the connector. To help ensure a durable connection, you may apply a very small amount of polyimide resin halfway around the column tubing near the opening of the Press-Tight connector. Allow thirty minutes to air dry.
Now you're ready to install the column. After the column is installed and the carrier gas flow is on, there are several important steps you should perform before using. Leak check the connections before and after the column is heated using an electronic leak detector. Test the integrity of the connection by injecting an unretained compound and carefully inspect the peak shape. Symmetrical peaks indicate a proper connection.
It is important to note that the connectors cannot be reused once they are heated because the polyimide residue cured inside the connector will prevent sealing. If you used a polyimide resin, once you have established a leak-free connection, cure the resin by heating the column in the GC oven using the following program, while keeping the flow on. Note that heating polyimide-coated tubing above 350°C for extended periods may cause the polyimide to dry out, resulting in a poor seal. Be sure to periodically leak check the connections to confirm seal integrity and that’s it! You’re done! That’s all that’s needed to create a seal between two columns.
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