DMHA peak in MS spec

[mk12]

Hi!

I was working with 10mM DMHA( dimethyhexylamine) in mobile phase.Now I have switched to formic acid 0.1% I have DMHA ion (130) all over my mass spec now interfering with my analysis. How can I remove that from my mass spec? I tried overnight was with 50:50 org: water and cleaned my interface.

But i still see huge peak of 130 in my mass spec please help

thanks in advance

[krickos]

well

not much info in details there, but could it be that you have "saturated" your system with an ion pair reagent, switching to the acid makes it "leach" out all over the place and by trying to clean out a reagent with a pka of ~10(?) with organic/water (no pH control) is not particular efficient?

I do not consider myself a LC expert but we usually dedicate ion pair columns.

[mk12]

Hi! thanks for your reply.

can you suggest some othe washing methods which will help me get rid of DMHA peak...