Hi,

I have an issues with the detection of a standard on LC-MS.

I run MGDG standard (prepared in methanol, LC-MS grade) on HILIC BEH Amide column; the run is 15 minutes long, using a gradient from 95:5 to 70:30 of acetonitrile:ammonium acetate (in water) 10mM, pH 9.2 . For the nature of the compound, I select +ve for the analysis.

The chromatogram shows that the m/z I'm looking for (parent ion+adduct from the solvent) is eluted twice, around 6 AND 8 minutes. This result is consistent for all the concentration I used for the calibration curve.

I'd prefer to have a single peak for the compound to have a reliable quantification: how can I solve this issue, please?

Thank for the help!