Dear Milad, Rob and Junhai
Great conversation. I just started being active in this forum and noticed your conversation. We can certainly help you with these questions if they are still of interest.
I agree with Rob that 0.200ml/min can be too much flow and results in a very wet spray, especially with 50% H20.
My starting point with CHCA sprayed on tissues, is:
<Solvent>70% ACN + 0.1%TFA</Solvent>
<Temp>75</Temp>
<NumPasses>4</NumPasses>
<Concentration>10</Concentration>
<FlowRate>0.12</FlowRate>
<Velocity>1200</Velocity>
<TrackSpacing>3</TrackSpacing>
<Pattern>HH</Pattern>
<Pressure>10</Pressure>
<GasFlowRate>3</GasFlowRate>
<DryTime>0</DryTime>
<NozzleHeight>40</NozzleHeight>
Note that this protocol has 70% ACN (instead of 50%). Higher organic content makes the spray evaporate faster. The temperature of 75 Deg C is close to the boiling point of the mixture but should be stable and will evaporate quickly.
Feel free to email me at acreissen(at)htximaging.com if you need more information
Alain
