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- Posts: 14
- Joined: Sun Oct 16, 2011 9:38 pm
I was trying to use LC-MS to analyze a couple of steorids. Several compounds are just fine, but I got some difficulty with DHEA, DHEAS and Estradiol. I tried both methanol and acetonitrile as mobile phase B, water is mobile phase A. No acids were added. These three steroids just show no signals even at a relatively high conc. I checked a few references on website and don't see strange comments for them, so I feel very strange why they are not detected in my exp. I was using positive ion mode with Nanospray. Is it because I didn't have formic acid in the mobile phase? Other similar steroids such as cortisol, Corticosterone, etc were giving nice signals