I am working on the preparation of molecular imprinting polymer which was used as the stationary phase. The polymer was made by terpolymerizing Methacrylic acid, 2-vinylpyridine and Ethylene glycol Dimethacrylate. Acetonitrile or the mixture of acetonitrile and methanol with a very tiny ratio of acetic acid was used as the mobile phase. I was trying to figure out which types of solvent could be used as the void volumn marker. I appreciate for any kind of response.

Could someone please explain what molecular imprinting polymers are used for?

Thanks a lot.

Xiaolin,

If you are using a UV detector I would inject a dilute acetone solution or prehaps a dilute sodium nitrate solution to use as a void volume marker.

Regards,
Mark

Mark,

Thanks very much for your comments, I have tried acetone as the VM, But I think Acetone is not good enough because we have carboxylic acid group and secondary amine group in the stationary phase, there should be some interaction between them, is there some other chemicals which is more suitable as the void marker in my case?

Xiaolin,

I don't think acetone wouold be a problem but even so, the sodium nitrate should be a good marker also.

Regards,
Mark

Sodium Nitrate is a good marker for a reversed phase system because nitrate is UV absorbing and ionic. You need to describe the mobile phase and stationary phase more completely since it looks to be almost like a GPC column. In that case there may be a more appropriate marker since the goal for any marker is a low partition coefficient.

i know uracil is used often as the marker in RP HPLC

Yes, uracil is well-known non-retained compound for RP HPLC. In case the separation is based on other than RP or mixed retention mechanism you should decide what is the suitable non-retained compound for void volume evaluation.

Dr.Alex Weisman
Chemagis,
Israel