Schwartz et al (J Mass Spec 2003; 38:699) discuss using a nebulizer to spray matrix onto the section. Does anyone have specific experience with this technique (i.e. hints, particular setups, better alternatives)?
Yes, it works. We use it in our lab and it’s relatively robust and reproducible. In a typical coating we spray 8 ml of saturated CHCA solution in 50:50 ACN/0.1%TFA using a TLC sprayer. The authors state:[quote] The sample is allowed to dry for 1-2 min before the next coating cycle[/quote]
IMHO it is a requirement to never let the sample completely dry in between spray cycles ❗ .
Markus, could you elaborate on the flow rate during spraying, and what kind of surface is covered by the 8 mL of matrix solution?
Currently we use a home-built nebulizer, but only spray at 40?L/min because at higher flow rates the sections get too wet and the liquid is blown laterally over the sections due to the gas flow.
I can only estimate the flow rate of of our spray since we use a TLC sprayer operated by Bernoulli’s principle. We ajdust the spray to form a fine mist setting the pressure to approx 0.8 bar. This results in an estimated flow of 1 ml/min. We spray 8 ml in 30 minutes, with cycles of 10 s spray and 30 s pause.
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