HILIC glycan Premier Column

I have some difficulties optimizing my HILIC gradient (the column:186009549) for my glycan method. The blanks injections shows, from inorganic towards organic solvents, observing clusters in the range of 758.25, 832.27, 906.29 etc.. The mass difference is 74Da and is referring to 'Polysiloxane, silicone rubber polymer (typical series at m/z's 684, 758, 832, 906) Si(CH3)2O (from rubber). My mobile phases are 0.1%FA in Water and 0.1%FA in ACN. Do you have any suggestion how to get rid of them? Thanks in advance!


  • Hi Elisa,
    There are quite a few articles in the Knowledge Base that refer to Polysiloxane contamination coming from vial caps.  The first step would be to isolate and remove the thing causing the contamination, then clean the residue.  In my experience, the best cleaning solution is the "magic mix" 25:25:25:25 MeOH:ACN:IPA:1% Formic acid in clean water but there is lots more information in the Controlling Contamination guide.

    Good Luck!