It is well-known that reactive free radicals and electrons can
be generated by a glow discharge. The electrolyte cathode
atmospheric-pressure glow discharge (ELCAD)19 is a relatively
new optical emission source that uses an electrolyte solution as
the cathode in a dc glow discharge, with a metal counter electrode
positioned in the atmosphere above the solution. It operates in
an environment saturated with water vapor and is reported to
contain H and OH radicals and free electrons.