Page 1 of 1
Ask help for seperation DOTA & DTPA related compounds!
Posted: Mon Apr 10, 2006 4:50 am
by Z.-X. JIANG
I have some difficulties in seperation some compounds like DOTA & DTPA which contain 3-4 COOH groups and 4 tertiary-amine groups. Those compounds came out either at the dead time (reverse phase column) or disappeared (normal phase column). Is there anybody with any experience on such compounds? Thanks !
Posted: Mon Apr 10, 2006 10:18 am
by Rafael Chust
One way of dealing with this stuff is playing with buffers - if your column allows it - frpm pH 2 to pH 11, and see how your analytes reacts.
I assume you are doing RP at low pH, otherwise you should ge retention.
Posted: Mon Apr 10, 2006 12:04 pm
by Patrik Appelblad
I'd say that your compound should be run under HILIC conditions.
Compounds that elute in the void on RP columns or require addition of IP-reagents are those best suited for HILIC. I would also bet that your compound have a very high interaction with the NP column you tested, which incidently would be the same if you tried a silica HILIC column.
There are though other HILIC phases available, check previous post @ this forum, and our zwitterionic phases might be one suitable alternative.
If you are not familiar with HILIC as technique, a copy of our "HILIC guide" can be ordered via our homepage.
Posted: Mon Apr 10, 2006 2:31 pm
by yangz00g
HILIC will definitely work. You may also want to try ion exchange.
Posted: Mon Apr 10, 2006 2:58 pm
by SIELC_Tech
Z.-X. JIANG,
We have a method for DOTA and related compounds on Primesep D column. It is not on the web yet but if you provide us with your email I will send you technical note on DOTA retention/separation.
Regards,
Vlad