Dear colleague, as much as i know the LC-MS is limited in term of compounds identifications, the only way to identify a compound by classical LC-MS is by using standards. In my case I work with plant extracts and to identify the molecules on a mixture, I do preparative HPLC in order to fractionnate the extract, followed by column chromatography to purify every fraction, then an NMR analysis to determinate the structures i take protons and carbons, I wish you good luck.

Best regards.

Thanks, Hicham for your reply but my metabolite is giving excellent results but stiil a question in mind and literature also...

Thanks Navid and Davies