Please mount a new column. Ensure the connection from the transfer line to the column, and from the column to the emitter (if applicable) are properly seated and tightened as improper connections may lead to carry-over.

Run one standard sample injection (10-50 ng HeLa or K562; where concentration is dependent on which MS you are using) followed by three standard blank injections - follow entire Evotip preparation protocol but load 20 μL solvent A (water with 0.1% FA) as your "sample" for the standard blank. Estimate the amount of carry-over between the last standard sample injection and each blank injection.

Is carry-over still observed?

Sample Carry-Over