Hi, i´m looking for some hints on seperating
Octylphenole, Nonylphenole and Nonylphenole-Ethoxylates on a Hypercarb in one (single) run. i do not have any experiences with that kind of coloumn, and all in all just some (poor) knowledge in coloumn-materials and retentionmechanisms in general.

On the one hand i have with normal phase coelutions (Nonylphenole and Octylphenole) and on the other hand on reversed phase (Nonylphenole and EO´s)
I don´t have LC-MS, so the problem could be finally solved in a way on looking on the specific masses, if the separation is not fine ( at least i think so ;-) .... and of this i should find a system for seperating these analytes with common HPLC / fluores-detection and DAD.

on my opinion ( more based on a feeling *g*) a Hypercarb would help. if someone has any experiences on that kind of coloumn-material, it would be nice to get some response.

Many thanks in advance,
Hajo

ah, yep, .... if u want to ad some comments,
please forward also to my e-mail addy, that would be very nice, ...

many thanks

Try to manipulate the pH in reversed-phase. You should be able to ionize the phenoles in the alkaline

Several years ago I carried out a study on the degradation of these compounds. There is an enormous amount of literature on their separation. GC gives excellent results I seem to remember. Gradients using TFA/ACN/H2O were OK on C18. If you are set on using Hypercarb ring the suppliers for technical help, it will save you a lot of development time, and believe me developing methods on Hypercarb is not a trivial task!

I'm curious about why developing methods on Hypercarb should be any more trouble than conventional reverse-phase method development.

I would like to help but I don't know the differences between a RP and Hypercarb method?. What does an Hypercarb method implies? Special column, reagents, equipment?

Thanks

Hello all,
nice talk, but lets give some facts: Hypercarb is produced by filling Silica particles with polymer, graphitising the polymer and then dissolving away the silica! Result is a 7µm spherical particle, 60% porous with a surface area of 175-200m2/g!pH stable across the whole range 0-14, max. pressure 400bar, and mean pore size 250A, no swelling, no shrinkage. And it is 100% carbon, can be used under NP or RP conditions. Manufacturer was Shandon, now a Thermo Hypersil company. But I'm not sure if the company name didn't changed again. Dr. Bulvinder Kaur is since Hypercarb started their resident Hypercarb expert, and so far I know still on board. Many years ago Shandon published a brochure, author was Dr. Kaur. If you can get it, please have a look in it. Last chapter - Choice of solvents - will give you an idea why anonymous mentioned it is not a trivial task. And please think about what will happen when oxygen comes on the carbon surface (please don't ask how).
For separation of Phenole RP columns are often mentioned, and you can try it on silica or polymer based column materials, or on Hypercarb. Also capillary GC is possible. Think about!
Have fun and good luck.
Gerhard

Regarding Hypercarb and common RP (jclark):
There is a multitude of possible type of interaction in Hypercarb, we did an anal. of oxalate, apparently on basis of charge transfer interactions. With this the pH adjusment was very tricky, giving the strangest peak shapes that I have seen when pH was slightly off from ideal.
Regarding nonylphenol:
I am helping a colleague to synthesize 14C-nonylphenol and am checking the reaction with NP (MP = dichloromethane) as well as RP (a newer "aqua" type, MP = 30H2O+67CH3CN+3iso-PrOH [modified from one of the many refs]), the RP has considerably better resolution. Since some nonylphenol isomers are separated there should be no problem to sep. octylphenol and especially the ethoxylates. Now, GC is incomparably better than the best RP-HPLC, its just more convenient to do HPLC first.
Nevertheless, it would be interesting to see what hypercarb does with nonylphenol isomers.

first of all many thanks for ur responses and suggestions.
Regarding to the entry of HW Mueller, ....
and Gerhard Kratz ( wishing me fun and good luck ;-) )

what do u (HW Mueller) describe a "newer aqua type coloumn" ? something like C30 ( instead of common used C18 RP material)?
concerning ur interest what a hypercarb will do with EO´s and NP, .... i can give u meanwhile some statements: the gradient i tried is form pure Acetonitrile to Dichloromethane ( both with 1%TriFluoroAceticacide for better peakshape)....
EO´s elute in the first 5 to ten mins, seperated according to their chainlenght, but not really resolved to the baseline; Nonylphenole and Octylphenole have been seperated really good ( with retentiondifferences about two minute) at a time of about 20 mins. so, all in all it looks quite good meanwhile. but we will see how that system will work with real samples tainted with matrix ;-)