Merck Gaurd column performance specifications?

[jambon]

Are there any Merck gaurd column specifications QC sheet as I could not find one on their website.
Please message me the column specifications sheet for PEEK coated gaurd column.

So if the document says passes test what tests are there that are carried out on a gaurd column such as this one?.

https://www.merckmillipore.com/IE/en/pr ... hoo.com%2F

[mattmullaney]

Agreed, Jambon,

The only info that appears in the specification sheet is that the 1504350001 product meets the requirement for visual specification for shipping. What information are you interested in regarding either the column hardware or the phase? Seems that you'll have to look elsewhere to find either bit of information. For guard column stationary phase info, this is not unusual, though.

[Andy Alpert]

Guard cartridges are intended to be relatively cheap items that you throw away more frequently than the columns that they protect. Speaking as a manufacturer, it would be uneconomical to test each guard cartridge individually in the manner that the columns are tested. You probably shouldn't expect Merck to do so.

[jambon]

Information such as what type of stationary phase. The stationary phase lot number. Typical plate counts. If it will affect peak tailing. What stationary phases are compatible. What plate count. Today I found the plate count for that column was 90 to 300 plates only for an analytr standard small molecule 200-300g/mole all that effort for a gaurd column but I was very curious I had to test it since I couldn't find that in literature. Interesting in that positioning the gaurd column after my c18 improved separation. So it likely exaggerates the c18 interactions.

[jambon]

Also the specifications for what biological samples are appropriate to preserve lifetime of the gaurd column and therefore analytical column lifetime.

[mattmullaney]

Hi Again, Jambon,

Well, this is a link to the brochure for the item you cited and the stationary phase:

https://www.emdmillipore.com/US/en/prod ... anchor_BRO

Seems that the guard column uses the exact stationary phase as the corresponding analytical column, in 5um particle size, sulfobetaine-derivatized silica, 200-angstrom pores, 135 m^2/g surface area. Column is 2.1 mm x 20 mm, so having such a "small" plate count seems reasonable to me. This is about all I was able to quickly glean from my searching. You could likely get the lot number for the stationary phase for this guard column from EMD by giving them a call...Dr. Andy Alpert pretty much summed everything else up that I could comment on above. He knows a heck of a lot more about HILIC than I do.

I'm a bit confused, did you put this guard column in front of or behind this C18 analytical column you're using?

As to the last question...I think that the only way you'll find out is by trying out your method with your matricies, and see what happens. Not sure to know how the matrix will affect the guard or analytical column w/o knowing more about what is in the matrix to start.

[jambon]

I put the gaurd column after the C18. I dont know what the particle size is 3.5 or 5 micron not available in the merck website. Is it the internal diameter difference or the particle size that is mostly contributing to the peak tailing. I read also semi porous material increases peak height with same peak area increasing sensitivity of the HPLC assay.