By Robert Auer on Monday, August 18, 2003 - 06:46 am:
Dear All,
We have got a separation problem of molecules covering a large polarity range, namely adipic acid, cyclohexanol, cyclohexanone and ethanol from cyclohexane. Our HPLC apparatus is equipped with UV-VIS and RI detector. Could you give us advices concerning the method development, i.e. a suitable eluent (mixture), pH, column?
We are grateful for your ideas,
Robert
By Anonymous on Monday, August 18, 2003 - 10:21 am:
Your problem is really tough.
I would try gel permeation column with RI. I don't think any gradient will work with UV, especially if you are looking at low % levels or less.
An acidic mobile phase might produce enols with the ketone however.
GC would be a better solution in my opinion.
Rod
By Anonymous on Monday, August 18, 2003 - 04:20 pm:
There is a way to do this, but you need an FID with your HPLC. Do you have one?
By bill tindall on Monday, August 18, 2003 - 07:40 pm:
To add to Anon. II's comment I would suggest a mobile phase of helium to go with the FID detector already suggested. This is a near trivial GC problem. In fact, it looks like the materials you need to separate would make a great GC column test mix!