I'm currently using triethylamine for separation of nucleotides on RP HPLC columns and they have very, very short lifetime.
I was recommended to use either double end-capped (as Zorbax XDB) or hybrid silica (as Water BEH).
Right now, I was using Zorbax EclipsePlus, which should be double end-capped as well and it should be rather higher class column than XDB, is that right? Or are the XDB columns even more endcapped or something like that?
But, what I want to ask more, our saler sent me prospect of Cogent Bidentate columns
http://mtc-usa.com/wcode_bc18.aspx
http://mtc-usa.com/wcode_type-c-cat.asp
of course the web page speaks in superlatives as it's their product, so I want to know if here is somebody with experience with these columns, because I never heared about them. However, that doesn't have to mean that much, as I'm no expert on HPLC columns.
So, could you recommend that column? Is it comparable with hybrid silica (because from my understanding it's different concept, although the result should be possibly the same)
Thanks in advance.
To your first question about XDB vs Eclipse. The XDB are specially designed to be used with basic modifiers to pH 10. I have used XDB to run over 70,000 assays per column.
To your second question, I have used the Cogent Bidentate columns for mildly basic compounds and used them with acid (trifluoro-acetic acid) and had good success at developing a method for drug intermediate purposes.
Thank you for the answer.
So XDB should be superior to EclipsePlus in my conditions, right?
In your opinion, are the bidentate column as excelsior as they claim? If they are, why are they not used more often? Do you think they are recommendable for my conditions? Which one of the three (XDB, EP, bidentate) would you pick, if you had to run with these conditions?
Hello Tomas, The challenge with some of the Waters columns such as the BEH is that it is aimed towards UPLC, not HPLC. The Cogent Bidentate C18 may not be the best choice for Nucleotides, but the Cogent Diamond Hydride is designed for Nucleotide analyses - in the acidic mode. The XDB may work but for all of the columns you need make sure the pore size is large enough - 300angstrom, not 80 -120 angstrom. Most applications I see are using a newer column technology with acidic mobile phase.
I hope that can help.
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