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Choosing a guard cartridge for LC

  • Nancy Schwartz
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So you have a guard cartridge holder of some sort, and you don’t have the guard cartridge to put inside.

If you happen to have missed that last blog post about the holder, click on the following link.

Choosing a guard cartridge holder for LC

Let’s determine what type of guard cartridge you need. A great resource is always the HPLC and UHPLC FAQs section of our website. If your analytical column is from Restek, the selection should be pretty straightforward.  Go to “Guard Hardware” on our website:

LC holder web search

Then select/click on the cartridge type on the left hand side that matches the description of your analytical column. These are shown according to our HPLC product lines based on the type of silica that is used. After selecting the column group, click again on the actual product that will be in the center of your screen.




At this point, a selection of cartridges for various bonded phases in that column grouping will appear. If you want to filter out and only look at the choices for your column phase, locate that phase in the Quick Filters menu at the bottom and click on it.

At that point, you will be shown the dimensions available for your column phase, which will be 10 x 2.1 mm or 10 x 4.0 mm. Except for our Raptor™ columns, the particle size is 5 um for all column groupings. The illustrations shown above are for an Ultra Aqueous C18 column and guard combination.

If you are using a Raptor™ column, the selection process is the same. However, you may notice that dimensions of 5 x 2.1 mm, 5 x 3.0 mm and 5 x 4.6 mm are offered. The guard cartridges are shorter (5 mm) and have 3 different IDs available to match the design of the new EXP Direct Connect Holders, which are used exclusively with the Raptor™ columns. You may also notice that the particle size for these are all 2.7 µm, which matches the packing material of the Raptor™ columns.

As mentioned in the FAQs, we do not offer guard cartridges for the 1.9 µm UHPLC columns. For these we still recommend either the UltraShield PreColumn Filter or the UltraLine In-Line Filter.

If interested, we have the following related videos available in our library for viewing:

Do I need an LC Guard Column?

Using Your EXP LC Guard Column Protection System

Using Your Trident LC Guard Column Protection System


I hope this helps with your selection of guard cartridges. If you still cannot find something that you need on our website and need help, please feel free to contact Technical Services. Thanks.

Learn more about Raptor™ SPP Core-Shell LC Columns