Chromatography Forum

I used the heated nebulizer for the first time recently. I was able to scan my compound when I infuse it at 0.5 micrograms/mL. However, when I tried to run several injection in LCMS-MS, I could not see a peak, even at a concentration of 500ng/ml.

I previously used turboionspray to run it but the least that I could see using LCMS was 100ng/ml. Our target is below 10ng/ml. That was why I resoted to using the heated nebulizer, hoping to get better sensitivity. Any advice or recommendations? Thanks!

What is your compound and LC conditions? The heated nebulizer is generally better for compounds with lower polarity while electrospray is better for ionizable compounds. The heated nebulizer is also less affected by sample matrix. Maybe you can run a higher concentration for testing until you get all instrument conditions optimized?

Just to check, were you infusing into your mobile phase, with the same flow rate that you use for the analysis?