HPLC seperation problem

[Ray_Delft]

Hi All,
I had a problem with seperating acetylene and oxaloacetic acid with HPLC method.
Some one could help????

[skunked_once]

Someone may be able to help if you supply more information on how you are attempting the analysis and details on the problem you are encountering.

[Ray_Delft]

Hi All,
I had a problem with seperating acetylene and oxaloacetic acid with HPLC method.
Some one could help????

to clarify this problem,
the substrates I am going to seperate have identical structure and acidity (i guess).

I have tried ion exchange column, ion exclusion column, can't work this out.
Therefore , I would really need some help for separating them. Like which kind of column I would worth to try.
Thank you very much in advance.

[Vlad Orlovsky]

What is your detection technique? My main concern is monitoring acetylene.
In terms of retention and separation your solutions is mixed-mode chromatography. Acetylene will retain by weak reversed-phase interaction and oxaloacetic acid will retain based on anion-exchange mechanism.
Here are few applications for neutral and acidic compounds:
http://www.sielc.com/application_165.html (vitamin C is acidic and Vitamin B2 is hydrophobic)
http://www.sielc.com/application_163.html
http://www.sielc.com/application_136.html

Contact me if you have questions.

You can also consider doing GC.

[Ray_Delft]

What is your detection technique? My main concern is monitoring acetylene.
In terms of retention and separation your solutions is mixed-mode chromatography. Acetylene will retain by weak reversed-phase interaction and oxaloacetic acid will retain based on anion-exchange mechanism.
Here are few applications for neutral and acidic compounds:
http://www.sielc.com/application_165.html (vitamin C is acidic and Vitamin B2 is hydrophobic)
http://www.sielc.com/application_163.html
http://www.sielc.com/application_136.html

Contact me if you have questions.

You can also consider doing GC.

Detection was done by a UV-Control detector at 210nm.
It is found that the peak of enol-OAA overlays with ADC

btw, does OAA's enol and keto form should compose two peaks in the HPLC measurement?