Chromatography Forum

Hi!
I've been using HPLC for years but with UV detectors. I'm using a more sensititve Fluorescence right now and I noticed that even HPLC grade MeOH has peaks. I also tested deionized water and it also has peaks eluting in the chromatograms. Do i need to use distilled MeOH? We used distilled water and filtered it after putting activated charcoal but there are still unwanted peaks eluting. I wonder what solvent type do I need use? Any help? Thanks.

-ghie-

Gradient or isocratic separation?

Isocratic sir.

-ghie-

Hi!
I've been using HPLC for years but with UV detectors. I'm using a more sensititve Fluorescence right now and I noticed that even HPLC grade MeOH has peaks. I also tested deionized water and it also has peaks eluting in the chromatograms. Do i need to use distilled MeOH? We used distilled water and filtered it after putting activated charcoal but there are still unwanted peaks eluting. I wonder what solvent type do I need use? Any help? Thanks.

-ghie-

Check the batch of MeOH and if its fresh batch filtering through 0.22 micron membrane may help.

This water has organic impurities resulting in ghost peaks.


Regards,

Amaryl.

If you are seeing artifact peaks in an isocratic analysis, the chances are good that those peaks are contaminants in your sample or diluent, not in your mobile phase. Artifact peaks in gradients are more likely to come from the mobile phase.

Check your vials, glassware, filters, syringes, pipette tips, etc. (anything that comes in contact with the sample).