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Columns differences
Posted: Fri Nov 20, 2009 3:44 pm
by Melissa
Hello everybody! Help me please!
I need to know if I can use this column: Zorbax Eclipse XDB C18 4.6 x 150mm x 5um; instead of this column: ODS LC-18 Luna phenomenex 150 x 4.6mm 5um, for sulfonamides' analysis.
What is the difference between them?
Thanks
Posted: Fri Nov 20, 2009 3:54 pm
by Consumer Products Guy
Most likely those two more-modern columns will work fine (likely better). Run with each and compare peak shapes and resolution.
Posted: Fri Nov 20, 2009 4:01 pm
by grzesiek
I would expect some differences, what kind of analysis are you doing? Some validated method?
Posted: Fri Nov 20, 2009 4:02 pm
by Melissa
The issue is that the method recommends phenomenex but I only have zorbax. So I worry about the packing of the column, i know that both of them are C18, but do they work similar?
Posted: Fri Nov 20, 2009 4:05 pm
by Melissa
I would expect some differences, what kind of analysis are you doing? Some validated method?
well... I'm going to start the method, so I have to validate it...
What kind of differences?
Posted: Fri Nov 20, 2009 4:10 pm
by grzesiek
"the method recommends phenomenex" vs "I have to validate it... " ????
how does the method recommends if it was not validated? Could you explain
Posted: Fri Nov 20, 2009 4:24 pm
by Melissa
"the method recommends phenomenex" vs "I have to validate it... " ????
how does the method recommends if it was not validated? Could you explain
jeje! ok! how i explain......... that method was developed in mexico and i want to run it in my lab, maybe i should verify instead of validate, but know my question is... if i change the column, do i have to validate?
do both columns work similar? I worry about the packing...
Posted: Fri Nov 20, 2009 5:05 pm
by tom jupille
Those columns may be broadly similar, but they are *not* identical. The Eclipse XDB is not in the ten "closest match" columns from either selectivity database on the USP web site:
(
http://www.usp.org/USPNF/columnsDB.html).
Unless the assay is a very simple one, you will probably have to make at least some modifications to the mobile phase in order to make the method work, and that *will* require revalidation.
Columns are cheap. Your time is valuable.
Posted: Fri Nov 20, 2009 5:53 pm
by Melissa
Thanks a lot!!!!! I really appreciate your help!
Posted: Fri Nov 20, 2009 7:55 pm
by JGK
However, in the current Phenomenex catalog the Penomenex Luna is listed as Phenomenex's "Direct Replacement" for the Zorbax Eclipse XDB
Posted: Sat Nov 21, 2009 9:36 am
by danko
Melissa,
In the light of all the good clarifications and suggestions above, I would just install the Zorbax column and test the method.
Regarding your worries:
do both columns work similar? I worry about the packing...
_________________
Melissa González
I don’t think you should worry too much. I can guarantee you that everything the Luna can tolerate, wouldn’t constitute any significant challenge for the mentioned Zorbax column.
And when all comes to all, the suitability of the suggested substitute depends very much on the desired chromatography per se.
For instance I’ve seen methods that only result in a single peak (the compound of interest) with no interference at all. In that case you may pick up the first and the best column in your drawer and use it successfully. In some cases there is even no need for a column (some people use the HPLC system/hardware instead of a spectrophotometer with an autosampler)
I’ve also seen people fearing other columns (especially superiorly performing) due to the risk of them seeing “thingsâ€