Peaks separation

Discussions about HPLC, CE, TLC, SFC, and other "liquid phase" separation techniques.

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what is the expected reasons for no separation of peaks of antibiotics on lc-msms all peaks almost appear close to each other
If components have similar or very slightly different affinity for phases (mobile and stationary) then there will be almost no difference.
In case of LCMS e/m also comes into game.

Try adding a 3rd solvent to your mobile phases, that is discriminatory. There are very few molecules that have a similar solubility in three solvents. Use a slow gradient ramp around these peaks.
What are your compounds? Usually antibiotics have a charge and mixed-mode chromatography is exploring small difference in ionic and hydrophobic properties of the molecule. In my 17 years using mixed-mode columns I only had one or two cases when compounds were not FULLY resolved. Let me know if I can help. Send me an email trough our website.
Vlad Orlovsky
HELIX Chromatography
My opinions might be bias, but I have about 1000 examples to support them. Check our website for new science and applications
4 posts Page 1 of 1

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