By ejd_dpd on Monday, August 9, 2004 - 11:49 am:

I am interested in doing 1/2 to 1 gram seperations of "druglike" compounds under 500 mw. Typically these compounds will elut on c18 running acn water. Interested in finding out what size column would be recommended. The suppliers tell me everything from 50mm to 100mm in diameter. Does anyone have experience with this size seperation and can reccomend a column.


thank you in advance

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By JA on Tuesday, August 10, 2004 - 03:59 pm:

I've only worked up to 21.2 mm id scale with <500 mg, but I would say that if I had to go any higher, I'd want to be pretty sure that I had an adequate analytical-scale separation for the "druglike" compound. This would include a good estimate of it's loading capacity on the chosen phase before I bought a huge, expensive prep column and perhaps the LC hardware to push the necessary 100-500 ml/min of mobile phase :-)

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By Uwe Neue on Friday, August 13, 2004 - 04:42 pm:

You can test the loadability on an analytical column packed with the same material as the prep column that you consider using. Then consider optimizing the loading conditions on the analytical column. Most of the time, the issue is not so much the column, but details of your injection conditions. You can optimize all this on the analytical column. Then you know how much you need to scale, and what the best column would be.
If you need more info, send me an e-mail.