the samples
were dried for 15 min. Norharmane (Sigma-Aldrich, Gillingham, UK)
matrix was applied to sections at 7 mg/mL in 2:1 chloroform:methanol
(v/v) using the TM-Sprayer M3 (HTX Technologies LLC, Carrboro, USA).
Eleven layers were applied with a drying time of 30 s between each
layer using a nozzle temperature of 30 °C with a flow rate of
120 μL/min. The velocity was set at 1200 mm/min combined with
a track passing of 3 mm allowing homogeneous matrix application.28 (link)