The Hg (253.7 nm) emission spectra obtained by conventional
pneumatic nebulization, vapor generation from the SCGD plasma,
and vapor generation from SCGD cathode electrolysis under
matched ICP conditions are depicted in Figure 3. The greatest
intensity was obtained from vapor generation by the SCGD
plasma; the signal is about 16 times of that produced by pneumatic
nebulization. Although electrolysis in the cathode zone also
produces volatile Hg species, its efficiency is much lower than
that of the SCGD plasma and is even slightly inferior to
conventional nebulization. Figure 3 clearly demonstrates the
feasibility of utilizing the SCGD as a vapor-generation method for
Hg determination when the sputtered/evaporated water vapor is
condensed and removed by a GLS.