Columns For Sale on ebay

[chembot]

I saw some nice column bargains on ebay for ion exchange but I was wondering what a chromolith speedrod column does?

Thanks!

[tom jupille]

It's a "monolithic" column. Do a search on the keyword "monolith" and look at some of the previous discussions on that type of material.

[chembot]

Thanks Tom! Also, I was wondering what is the current smallest particle size on the market? I heard about 1.3-1.5 micron particles. Do any commercially available columns have particle sizes smaller than this?

Thanks!

Mike

[tom jupille]

Not that I'm aware of.

[chembot]

I wonder which yields more separation speed:

Waters Acquity fast-LC columns or Monolithic columns

Anyone have a Waters Acquity?

Mike

[Kostas Petritis]

Mike,

In addition to my reply to your relevant post at:

http://www.sepsci.com/chromforum/viewtopic.php?t=2624

If you add the separation efficiency as a parameter (which it has to be taken into account), small particle technology has a competitve edge.

For us, the advantage of monolithic columns lies on the ease of packing smaller ID columns (i.e. <20 um) which is a problem with particle technology.

[chembot]

Thanks for the references.

Mike

[chembot]

Can you calculate the minimum particle size practically allowed by physics? I was trying to combine fundamental principles with
chromatography equations and see if one could calc this.

LOL (too much free time on my hands)

Mike

[tom jupille]

Depends what you mean by "practically"

The lower limit is 0 (open-tubular column).

For packed columns, you need to specify desired run time and pressure capability. If you have lots of time, the equations are all in Giddings book "Dynamics of Chromatography" http://tinyurl.com/8879e.

For very small particles / high velocities, column dimensions will become an issue based on the ability to dissipate frictional heat.

[chembot]

Scientific books are just too expensive. LOL

[chembot]

anyone know of place that sells scientific books at a heavily discounted rate?

Mike