double peak

[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

[Jackus]

Without knowing the exact structure we can give you only general answers. Isn't it possible that molecule may have more enantiomers?

[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.

[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