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double peak

Posted: Sat Jun 30, 2007 8:59 am
by tonja79
Hi at all,
I have another problem:
I don't understand why some time I have the double peak of same molecule. I analize aromatic amine.
Thanks
Antonio

Posted: Sun Jul 01, 2007 8:27 am
by Jackus
Without knowing the exact structure we can give you only general answers. Isn't it possible that molecule may have more enantiomers?

Posted: Mon Jul 02, 2007 5:02 pm
by Mark Tracy
This can happen if the pK of the analyte is close to the pH of the mobile phase and the buffering capacity of the mobile phase is low and the sample pH is mismatched. If this is happening in your case you can change the pH of the mobile phase so that it is farther away from the pk of your analyte, you can increase the buffering capacity of your mobile phase, or you can prepare the sample in mobile phase.

It can also happen if your compound has two isomers in a slow equilibrium.

Posted: Tue Jul 03, 2007 2:54 am
by ym3142
1, bad column;
2, over loaded column;
3, strong diluent;
4, bad connection;
5, degradation;
6, contamination;
7, low quality mobile phase if gradient