Rocket format HPLC column

[chromSep]

I recently came across Rocket Format - HPLC column. Its wide bore - high speed ccolumn format. Do anybody have experience with Rocket format HPLC column??

[danko]

Hi ChromSep,

I haven’t heard of rocket format columns, but it certainly sounds exciting.
Would it be possible for you to post a link to some info about them?

It was about time to introduce rocket science into chromatography

Best Regards

[grzesiek]

This seems to be short column (3-7cm) with high internal diameter (more than 5, usually 7).

It is short so short analysis time is to be expected
It is wide so it has enough volume to be used on older systems with higher extra column volume

[danko]

Is that all?

Let’s hope potential users don’t require high efficiency.

Best Regards

[grzesiek]

at least that's what I know, this didn't seem to be a great thing to me so I moved on, maybe there are people who are using this kind of format and they can tell more

[skunked_once]

It was about time to introduce rocket science into chromatography

Let's not do that!! I'm just starting to figure out the voodoo and witchcraft of chromatography

[LC_labrat]

I had a new boss that wanted to "impress" his colleagues. So we starting changing to rocket columns to reduce the run time- so we could run more samples. Of course the flow rate was doubled and run time was cut in half or more. The peaks got wider due to loss in efficiency but still met all criteria.

It may only take 10 minutes to run the sample, it still takes me the same amount of time to process the data to finished result, more samples=more processing=longer amount time for data analysis.

And the same number of samples that took 20 minutes to run per sample vs ~10 minutes, still could run overnight and be finished by the morning.

So for routine analysis a rocket column would not be my first choice, especially when looking at low level impurities. Needless to say we did not change all the methods.

[Bruce Hamilton]

About 9 years ago that the Platinum Rocket came out from Alltech. We purchased a couple of 3um C18 ( 53x7, 33x7 ) for "easy" separations on old HPLCs, hoping to speed them up, and also collect small fractions for further work.

Problem that we found was that peaks quickly broadened with repeat use.
I suspect that flow down the column wasn't as intended. We did try different flows, and running them vertical, to no avail. May have been our old hardware, but we didn't persist.

Turned out to be easier to use a combination of SPE and conventional columns.

Please keep having fun,

Bruce Hamilton

[JGK]

I've used them in the past for an analysis were were performing.

The analyses were short duration (3 minutes), but required high flow rates, we were running at 3 mL/min if I recall correctly.

You probably need to perform some sort of cost-benefit analysis to decide if this type of column is right for you. you may gain on shortened time but lose on mobile phase usage.

[Mattias]

Very much off-topic...

When I saw the title of the thread, I imagined the picture of a column with a wide diameter in the inlet, and a smaller diameter at the outlet. Could there be any advantages with a column like that? I guess they would be impossible to pack, so the discussion is surely theoretical.

[tom jupille]

When I saw the title of the thread, I imagined the picture of a column with a wide diameter in the inlet, and a smaller diameter at the outlet. Could there be any advantages with a column like that? I guess they would be impossible to pack, so the discussion is surely theoretical.

Interesting thought. You would have a linear velocity gradient along the column (slow at the inlet, fast at the outled). I'm not sure there would be any advantage, and I can think of a disadvantage if you have small enough particles to be near the minimum of the van Deemter curve.

[Kostas Petritis]

Mattias and Tom,

Believe or not, these columns exist... The type of chromatography is called "ballistic chromatography" and the columns are called "magic bullets" . Those are commercialized by Michrom.

You may find some more info and specifications at the links below:

http://www.accessmylibrary.com/coms2/su ... 346717_ITM

http://www.michrom.com/Products/LCConsu ... fault.aspx

Learning something new everyday

[Uwe Neue]

Yes, these columns and these ideas have been around for a long, long time. If you look at this from the standpoint of backpressure versus performance, a bit of algebra will tell you that a column with a non-uniform diameter will always loose. As you can see, there is no magic in these things.

[chromSep]

Thanks to all . . .

Because of its short length wide bore configuration with small particle size; theoretically it seems logical to achieve high performance / productivity on conventional HPLC. I was just wondering if anyone could give a practical opinion. Thanks . . .