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C18 30 mm * 4.6 mm (2.4 uM) columns

Posted: Mon Aug 06, 2018 7:43 pm
by dap
Hello.
We found Thermo BDS 30 mm * 4.6 mm (2.4 uM) column is almost perfect one and validated many methods with this column. Unfortunately Thermo hid this column from web catalog ( https://www.thermofisher.com/order/catalog/product/28105-052130 ) that made us frustrating. Are there any pharmacopoeia allowed alternatives without particles size change?

Re: C18 30 mm * 4.6 mm (2.4 uM) columns

Posted: Thu Aug 09, 2018 1:29 am
by tom jupille
Check the USP. I believe (from memory) that you can make particle diameter changes so long as the column length to particle size ratio stays constant. You *do* have to pass system suitability, of course.

Re: C18 30 mm * 4.6 mm (2.4 uM) columns

Posted: Sun Aug 12, 2018 1:04 am
by mattmullaney
Hi DAP,

2.4 um diameter particles do not seem to be a typical size across multiple vendors. I'd think if the pharmacopeia recommended alternatives that each would have this information available upon request (USP occasionally lists multiple stationary phases for some of their methods, at least).

Looking at this website,

http://www.hplccolumns.org/database/compare.php

Chromegabond WR C18 (ES Industries), Viva C18 and Pinnacle DB C18 (Restek), and Superspher 100 RP-18e (MilliporeSigma) may be good alternatives--none of these is available containing 2.4 um diameter particle size.

Is it possible to request a special standing order of the Thermo BDS in 2.4 uM size in 30 mm * 4.6 mm column format?