Chromatography Forum

Vlad, thank you, sir

Probably our server was down, on Tuesday, i'll be back and respond.

Hi Avitan,

Here is two methods for you: one is UV and another one is LC/MS/ELSD compatible.
Toluidines are retained by combination of reverse phase and ion exchange mechanisms. ACN will have the same effect on toluidines as in reverse phase chromatography. In order to use ion-exchange mechanism and decrease retention time you need to increase buffer concentration, if you would like to increase retention time then decrease buffer concentration.

http://www.sielc.com/application_120.html

Happy New Year!

We are willing to develop free method for anybody. Contact us if you would like to use this opportunity:

http://www.sielc.com/Services_MethodDevelopment.html

Regards,

Vlad

I haven't got a reference but porous graphitic carbon (tradename: Hypercarb) may also work.

Use these words (and your compound names) in a "literature search" and you should come up with some starting conditions.

Rob, thank you for your answer

Well, some results:

I've achived baseline-to-baseline separation for mixture at low concentration level on Phenyl column (one of YMC Pack and one Inertsil Phenyl-3 ), but when I injected sample at 100% it covers all three of them.

SiELC application (see 2 posts above) simply works. Great selectivity - plenty of posibilities to play with parameters , again, thank you, Vlad!

If I'll do some additional experiments, this section wil be updated...

Thanx for all discussion participants. I've learned a lot ...

Have you tried an other RP column?
We have a PFP Fluophase column ( pentafluorophenyl) giving the separation of these three isomers.
Do you want me to send it to you?

Thierry

I made a mistake; the application is on a RP Fluophase column ( C6 perfluorinated C6 bonding).
We also have the Hypercarb column ( Porous Graphitic Carbon) that may solve the problem. We have so many applications on this particular column about isomers
More informations about Hypercarb column?

Thierry

domenger, thank you for your reply and, yes, please, e-mail it to me.

I've had unsucsessful try with toluidines on FSP-RP column before ... [/b]

If you're willing to try normal phase, do the following:

Supelcosil "DIOL-like" DIOL column (don't know what DIOL like means, but that's what is in their catalog) We use this for a variety of NP methods and find them very rugged and reproducible.

0.25% IPA/1% Butyl Chloride in Heptane at 1 mL/min and 35 deg C (or some stabilized T around there)

UV detection (254 nm I think)

We use this to separate various aniline derivatives, but it might separate the positional isomers in your problem. NP is often good for that.

Thank you, ljc, that's interesting approach too