Chromatography Forum

Hi Bruce, looks like sigma are saying a similar thing in terms of plate count 240,000 N/m - see http://www.sigmaaldrich.com/supelco/app ... 307181.pdf
I'm looking forward to testing this column to see if it can indeed acheive such a high resolution. Sounds like it might be a better bet than the monoliths in terms of efficiency.

I'm sure I saw a similar product from Shimadzu several months back. They had a 2.2 um particle column - and were also claiming some kind of manufacturing technology that gave a very narrow size range.


Thanks

Our approach is slightly different. Shimadzu uses conventional porous C18 material. But our message is that the gain in plates compared the increase in pressure for 2.2um particles is much better than for 1.7um participles.

The Hallo column principle looks interesting. I never tested them, so I can only speculate.
But if I see the results, I would say; buy non porous column. These columns have no internal surface at all!! But these columns have also a C-term and a much lower surface capacity. I see nothing about that here.

The monolith has still the future. A new generation monoliths will come soon and have better performance that 1.7 particles.

Koen

Regarding your last comment 'New generation of monoliths with performance of 1.7 um particles'

Wow! Tell us more!

Is such a thing really possible.

Thanks Adam

This thread kind of died off - maybe due to Pittcon. But I'll try it again.

Does anybody have any knowledge of these new monoliths (mentioned above) that are supposed to behave like 1.5 um particles.

How did they do it? What company is working on it? etc.

Thanks Adam

Hi Adam,

I haven’t heard of monolithic columns behaving like sub 2 μm particle columns, but I’m sure it’s a pretty realistic possibility in the near future.
The 2 most important parameters that make sub 2 μm particle columns more efficient than for instance the 5 μm columns, are the larger surface area per column volume and just as important if not more, the small inter- particle distances. Both parameters can be incorporated in/transferred to a monolithic material. The trick is smaller pore size, which means grater number of pores per column volume and it goes without saying less void volume, where the diffusion takes place.
Additional gains will be lower pressure than particle based columns (although higher than the pressure we experience with the present monoliths) and possibly better physical stability.
I hope somebody gets the idea, so that we soon can purchase this type of columns – not a bad prospect

Best Regards

Ascentis Express column have surface area similar to about 225 m2/gram. Loading is similar to or better than sub - 2 micron columns.