Difference Btw Ultrasphere Octyldecyl Silane & XTerra®C18

[Organic_chemist]

Hi Matt!!

I am actually working on similar kind of stuff (99mTc(CO)3(H2O)3) but most of the reference papers used RP C18 having silica based supporting material.

[mattmullaney]

Hi Organic_chemist,

Understood. Based on the little I know of separating EDTA-Complexes, I think I'd stay away from the polar-embedded phases, then. Sometimes the names of the columns are tricky...another case in point (unrelated to what you're doing) is the separation of monodechlorovancomycin from vancomycin B by USP. The PF-recommended column is Xterra RP C18, the polar-embedded phase. PF lists two alternate columns, Agilent Eclipse XDB C18 and Thermo Hypersil Gold C18. I tried out the Eclipse column for this separation and know that in my hands the Eclipse doesn't work nearly as well as the Xterra column. Trying out Tom's suggestion, you would see from the equivalency website that Xterra and Eclipse are not nearly the same in terms of their behavior. BTW, do you need a suggestion for an alternative column for the Ultrasphere? Otherwise, I agree with you that in this case Xterra could be unsuitable for the application you're working with.

[Organic_chemist]

Hi Matt!!!

Mostly in our Laboratory we prefer to use Water XTerra column maybe due to the reason it is easily available.

Water XTerra MS C18 silica type B which seems similar to Ultrashpere and I think that will do the job for me in case if i purchase this one.

Thanks for your comments!!!!!!!

[mattmullaney]

Hi Organic_chemist,

Please, I urge caution. Here is a link, same type of site as Tom Jupille cited above, this is the site I use more often than USP's. Same principle of operation, I know the gentleman that set the site up a little bit when I used Zirchrom columns:

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

Ultrasphere is a product that Hichrom (U.K.) sells...to use Dwight Stoll's site, go to section #1, find and click on Hichrom Ultrasphere ODS, then go to section #3 and click on Waters to compare Ultrasphere directly to the Waters' products Dwight has looked at. The Fs is 18.09 for the two columns...that isn't that close to me...Like Tom, I have had good success with Fs </= 10, purists suggest </= 3. Zorbax StableBond 300A C18 seems a good Ultrasphere match...Fs = 6.87, for example.

[Organic_chemist]

Hi Matt!!

Thanks for your comments, it's really useful.

stay blessed!!

[mattmullaney]

My Best Wishes in return, Organic_chemist!

[mbm9332]

Hey,

Sorry if I am reading this wrong but the triethylammonium IP agent you are using would not retain a positively charged metal ion complex. It would just shoot right through. You would need a negatively charged IP agent.

About the method gradient, is there any kind of reequilibration prior to the next injection? I would think the triethyl would come off relatively easy in 100% MeOH. If there is not any reestablishment of the IP agent on the stationary phase then there wouldn't be much retention of the analyte when injected.

Mike

[mattmullaney]

Hi again,

Discovered today a weird thing I missed before, Ultrasphere C18 behaves similarly to Waters Acquity BEH C8 of all stationary phases!

I may actually get to "bear this out" with a separation using the XP version of that BEH C8 phase. Not near to the separation you're trying out, but kind of weird and neat anyway.