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Posted: Thu Sep 03, 2009 1:05 pm
by Bryan Evans
There can be an enormous differences in selectivity between ODS phases, one just needs to know what to look for.
That being said, of course ODS is not always the optimal phase for the separation.
Ruth, if you can post data on here, it will be helpful.
Posted: Thu Sep 03, 2009 1:10 pm
by Ruth
@Bryan Evans: which data would you like to see? Chromatograms?
Posted: Thu Sep 03, 2009 1:16 pm
by Bryan Evans
Hi Ruth,
Yes, (chromatogram) + (gradient profile / flow rate / column temp / mobile phase) + (sample prep information that provided the best results)
Also, as much information as you can give about the sample matrix & analytes themselves.
Thanks!
Posted: Thu Sep 03, 2009 1:23 pm
by Ruth
@ Bryan Evans: How can I put this information on the forum? Or can I send it by mail?
Posted: Thu Sep 03, 2009 1:30 pm
by Bryan Evans
Hi Ruth -
This link below has information as to how to embed data on the forum:
viewtopic.php?t=2617
If possible, it is best to post data on here. That way we all learn.
Posted: Thu Sep 03, 2009 1:48 pm
by Ruth
@Bryan Evans: It doesn't work by using the link you proposed. Any other options?
Posted: Thu Sep 03, 2009 4:57 pm
by Camisotro
@ctroster: I tried already similar gradients before, but just to be sure I tried the one you recommended... Unfortunately, no change in matrix effect... I am afraid that by changing the mobile phase conditions the ion suppression won't dissappear.
Well it was worth a shot. I still recommend visualizing the ion suppression with post-column infusion under a few different mobile phase conditions (including something ridiculous like 10% isocratic, just to see how long it lasts before it stops); this may give you a better shot at identifying both SPE and chromatographic conditions that reduce the interference.